Alberto Mestas-Nunez, Texas A&M University Rate Professors

Alberto Mestas-Nunez

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School: Texas A&M University
Campus: Corpus Christi
Department: Environmental Science
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Location:
Corpus Christi, TX
Dates at Texas A&M University: April 2008 - November 2011
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Biography

Texas A&M University Corpus Christi - Environmental Science

Associate Professor of Research at The University of Texas at San Antonio
Research
Alberto M.
Mestas-Nunez
San Antonio, Texas
I am a physical oceanographer researcher and educator that studies the role of the ocean in climate variability and climate change. I base my research in the statistical analysis of remotely sensed and in situ observations and model output.

Experience

Texas A&M University-Corpus Christi
Research Associate Professor
Alberto worked at Texas A&M University-Corpus Christi as a Research Associate Professor
Texas A&M University-Corpus Christi
Associate Professor
Taught Introductory Oceanography, Physical Oceanography, Climate Variability, and Introductory Environmental Science courses.
University of Miami
Assistant Scientist
Alberto worked at University of Miami as a Assistant Scientist
University of Miami
Associate Scientist
Performed research in air-sea interactions and climate variability.
National Science Foundation
Program Director
Help manage the Physical Oceanography research program.
Harte Research Institute for Gulf of Mexico Studies
Harte Research Associate
Alberto worked at Harte Research Institute for Gulf of Mexico Studies as a Harte Research Associate
The University of Texas at San Antonio
Associate Professor of Research
Alberto worked at The University of Texas at San Antonio as a Associate Professor of Research

Education

Oregon State University
Master's Degree
Physical Oceanography
Oregon State University
PhD
Physical Oceanography
Instituto Tecnológico de Buenos Aires / ITBA
BS
Oceanography

Publications

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007
Remote Sensing Letters
The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean
Journal of Geophysical Research-Oceans
Uncertainties in turbulent ocean‐atmosphere heat flux estimates, both among the estimates and between them and ground truth, suggest that further comparisons are needed. We analyze estimates from the French Research Institute for Exploitation of the Sea (IFREMER) and the Woods Hole Oceanographic Institution’s Objectively Analyzed air‐sea Fluxes (WHOI OAFlux). The IFREMER products are based on satellite observations and the WHOI OAFlux ones on data from satellites, buoys, and ships assimilated into numerical analyses. We focus on the Atlantic sector (70°W–30°E, 45°S–45°N) during 1996–2005, where the variables that enter the bulk formulae for computing fluxes (wind speed, sea surface and air temperature, and specific humidity) can be evaluated against buoys in the Prediction and Research Moored Array in the Atlantic (PIRATA). Since WHOI assimilates PIRATA observations, we have added two independent buoy data sets: FETCH and ROMEO. To examine how each variable contributes to the difference between estimated and buoy fluxes, the method of Bourras (2006) is applied.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Can beach dune ridges of the Texas Gulf Coast preserve climate signals?
Geo-Marine Letters
A study of the evolution of North Padre Island (southern Texas Gulf Coast) dunes was carried out using LIDAR topographic data, dune vibracores through the center of the dunes, and grab samples of shoreface sand at four locations along a cross-shore profile. Grain-size analyses of the vibracores show vertical variations in shoreface sand deposition over decimeter depth intervals. A dune ridge growth model is introduced that describes the dune vertical accretion rate as a function of island progradation and freshwater lens expansion. This model allows indirect dating of the dune core samples based on a known island progradation rate (1 m/year), and height and spacing of the dunes calculated from the topographic data. A sand provenance model is also proposed that links the sand deposition in the dunes with sand sourced from various depths along the shoreface profile, depending on storm activity. We present evidence linking the changes in storm-sand deposition in the dune cores with yearly climatic fluctuations in the Gulf of Mexico associated with landfalling tropical storm activity in the period from 1942–1965. This record of storm-induced sand variability is negatively correlated with El Niño-Southern Oscillation (Pacific) sea surface temperature variability, and positively correlated with North Atlantic decadal sea surface temperature variability.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Improvement in air-sea flux estimates derived from satellite observations
International Journal of Remote Sensing
A new method is developed to estimate daily turbulent air–sea fluxes over the global ocean on a 0.25° grid. The required surface wind speed (w 10) and specific air humidity (q 10) at 10 m height are both estimated from remotely sensed measurements. w 10 is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T b) from the Special Sensor Microwave Imager (SSM/I) and q 10 is developed. It is an extension of the author's previous q 10 model. In addition to T b, the empirical model includes sea surface temperature (SST) and air–sea temperature difference data. The calibration of the new empirical q 10 model utilizes q 10 from the latest version of the National Oceanography Centre air–sea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q 10 exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are –0.04 g kg−1, 0.87 g kg−1, and 0.95, respectively. The new satellite q 10 is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10 m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25° spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5 W m−2, 27 W m−2, and 0.89, respectively.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition
Journal of Sedimentary Research
Gum Hollow Delta is a small microtidal, aggradational to slightly progradational, hyperpycnal, tropical-cyclonedominated delta in Nueces Bay (Texas). The delta formed over the past 80 years following anthropogenically diverted, high sediment-laden stream runoff through Gum Hollow Creek into Nueces Bay. Gum Hollow Delta formed episodically due to high runoff and increased discharge in Gum Hollow Creek and temporarily elevated sea level during Gulf of Mexico tropical cyclones. The delta is 600 m long, 1000 m wide, and 1.6 m thick. Fifty-one vibracores were taken along four dip transects and two strike transects to delineate the internal sedimentology, architecture, and geochronology of the delta. The delta consists of nine bedsets (tempestites) representing deltaic growth events. Internal stratigraphic correlations were constrained by the identification of significant widespread flooding surfaces and by 137Cs geochronology.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.
A mechanism for freshening the Caribbean Sea in pre-Ice Age time
Paleoceanography
Many believe that the Central American Seaway closed near 4 Ma, and that that closure led to increased salinity in the Caribbean Sea and stronger Meridional Overturning Circulation in the Atlantic, which facilitated the waxing and waning of ice sheets in the northern hemisphere. We offer an alternative explanation for Caribbean salinification. The atmosphere transports approximately 0.23 Sv (1 Sv = 1 million of cubic meters per sec) of fresh water (moisture) from the Caribbean to the Pacific today, but that amount varies by >20% during ENSO events. Regressions of moisture transport against the Niño-3 index, a measure of the sea surface temperature in the eastern tropical Pacific, show less moisture transport from the Caribbean during El Niño events than average. Abundant evidence indicates that at 3-4 Ma the eastern tropical Pacific was 3.5-4 °C warmer than today, and if so, an extrapolation of such regressions suggests that smaller moisture transport across Central America might account for paleoceanographic inferences of a smaller salinity difference between the Caribbean and Pacific at that time. Accordingly, that decreased salinity difference at ~3-4 Ma would not require blockage of relatively fresh Pacific water at ~2-4 Ma by the closure of the Central American Seaway, but rather would be consistent with a transition from El Niño to La Niña-like conditions in the eastern tropical Pacific around that time.

ESCI 1401

ESCI1401 Description

3.5(2)

Level:
Credit hours: 0

ESCI 1402

ESCI1402 Description

2(1)

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ESCI 3000

ESCI3000 Description

1(1)

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ESCI 3351

ESCI3351 Description

3(2)

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Alberto Mestas-Nunez

Alberto Mestas-Nunez

Biography

Experience

Texas A&M University-Corpus Christi

Texas A&M University-Corpus Christi

University of Miami

University of Miami

National Science Foundation

Harte Research Institute for Gulf of Mexico Studies

The University of Texas at San Antonio

Education

Oregon State University

Oregon State University

Instituto Tecnológico de Buenos Aires / ITBA

Publications

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

Improvement in air-sea flux estimates derived from satellite observations

Improvement in air-sea flux estimates derived from satellite observations

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

Improvement in air-sea flux estimates derived from satellite observations

Improvement in air-sea flux estimates derived from satellite observations

Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition

Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

Improvement in air-sea flux estimates derived from satellite observations

Improvement in air-sea flux estimates derived from satellite observations

Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition

Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition

A mechanism for freshening the Caribbean Sea in pre-Ice Age time

A mechanism for freshening the Caribbean Sea in pre-Ice Age time

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

Improvement in air-sea flux estimates derived from satellite observations

Improvement in air-sea flux estimates derived from satellite observations

Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition

Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition

A mechanism for freshening the Caribbean Sea in pre-Ice Age time

A mechanism for freshening the Caribbean Sea in pre-Ice Age time

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

The ENSO footprint in monthly satellite evaporation over the global ocean during 1993-2007

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Differences between two estimates of air-sea turbulent heat fluxes over the Atlantic Ocean

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

Can beach dune ridges of the Texas Gulf Coast preserve climate signals?

Improvement in air-sea flux estimates derived from satellite observations

Improvement in air-sea flux estimates derived from satellite observations

Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition

Record of historical Gulf of Mexico storms preserved in the stratigraphy of Gum Hollow Delta, Nueces Bay, Texas: An example of tropical-cyclone-induced hyperpycnal deposition