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• 1. [Article] Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Perturbations

  This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://journals.ametsoc.org/loi/mwre.

  Citation × Citation Citation Abstract Copy Title: Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Perturbations Author: Chelton, Dudley B., Skyllingstad, Eric D., Samelson, Roger M., de Szoeke, Simon P., O'Neill, Larry W., Perlin, Natalie This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://journals.ametsoc.org/loi/mwre. Title: Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Perturbations Author: Chelton, Dudley B., Skyllingstad, Eric D., Samelson, Roger M., de Szoeke, Simon P., O'Neill, Larry W., Perlin, Natalie This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://journals.ametsoc.org/loi/mwre. Close

• 2. [Article] Summertime Coupling between Sea Surface Temperature and Wind Stress in the California Current System

  Satellite observations of wind stress and sea surface temperature (SST) are analyzed to investigate ocean–atmosphere interaction in the California Current System (CCS). As in regions of strong SST fronts ...

  Citation × Citation Citation Abstract Copy Title: Summertime Coupling between Sea Surface Temperature and Wind Stress in the California Current System Author: Chelton, Dudley B., Schlax, Michael G., Samelson, Roger M. Satellite observations of wind stress and sea surface temperature (SST) are analyzed to investigate ocean–atmosphere interaction in the California Current System (CCS). As in regions of strong SST fronts elsewhere in the World Ocean, SST in the CCS region is positively correlated with surface wind stress when SST fronts are strong, which occurs during the summertime in the CCS region. This ocean influence on the atmosphere is apparently due to SST modification of stability and mixing in the atmospheric boundary layer and is most clearly manifest in the derivative wind stress fields: wind stress curl and divergence are linearly related to, respectively, the crosswind and downwind components of the local SST gradient. The dynamic range of the Ekman upwelling velocities associated with the summertime SST-induced perturbations of the wind stress curl is larger than that of the upwelling velocities associated with the mean summertime wind stress curl. This suggests significant feedback effects on the ocean, which likely modify the SST distribution that perturbed the wind stress curl field. The atmosphere and ocean off the west coast of North America must therefore be considered a fully coupled system. It is shown that the observed summertime ocean–atmosphere interaction is poorly represented in the NOAA North American Mesoscale Model (formerly called the Eta Model). This is due, at least in part, to the poor resolution and accuracy of the SST boundary condition used in the model. The sparse distribution of meteorological observations available over the CCS for data assimilation may also contribute to the poor model performance. Title: Summertime Coupling between Sea Surface Temperature and Wind Stress in the California Current System Author: Chelton, Dudley B., Schlax, Michael G., Samelson, Roger M. Satellite observations of wind stress and sea surface temperature (SST) are analyzed to investigate ocean–atmosphere interaction in the California Current System (CCS). As in regions of strong SST fronts elsewhere in the World Ocean, SST in the CCS region is positively correlated with surface wind stress when SST fronts are strong, which occurs during the summertime in the CCS region. This ocean influence on the atmosphere is apparently due to SST modification of stability and mixing in the atmospheric boundary layer and is most clearly manifest in the derivative wind stress fields: wind stress curl and divergence are linearly related to, respectively, the crosswind and downwind components of the local SST gradient. The dynamic range of the Ekman upwelling velocities associated with the summertime SST-induced perturbations of the wind stress curl is larger than that of the upwelling velocities associated with the mean summertime wind stress curl. This suggests significant feedback effects on the ocean, which likely modify the SST distribution that perturbed the wind stress curl field. The atmosphere and ocean off the west coast of North America must therefore be considered a fully coupled system. It is shown that the observed summertime ocean–atmosphere interaction is poorly represented in the NOAA North American Mesoscale Model (formerly called the Eta Model). This is due, at least in part, to the poor resolution and accuracy of the SST boundary condition used in the model. The sparse distribution of meteorological observations available over the CCS for data assimilation may also contribute to the poor model performance. Close

• 3. [Article] Dynamical Analysis of the Boundary Layer and Surface Wind Responses to Mesoscale SST Perturbations

  The dynamical response of the marine atmospheric boundary layer (MABL) to mesoscale sea surface temperature (SST) perturbations is investigated over the Agulhas Return Current during winter from a 1-month, ...

  Citation × Citation Citation Abstract Copy Title: Dynamical Analysis of the Boundary Layer and Surface Wind Responses to Mesoscale SST Perturbations Author: Chelton, Dudley B., Thum, Nicolai, Samelson, Roger M., O’Neill, Larry W., Esbensen, Steven K. The dynamical response of the marine atmospheric boundary layer (MABL) to mesoscale sea surface temperature (SST) perturbations is investigated over the Agulhas Return Current during winter from a 1-month, high-resolution, three-dimensional simulation using the Weather Research and Forecasting (WRF) mesoscale model. A steady lower boundary condition for July 2002 is obtained using SST measurements from the Advanced Microwave Scanning Radiometer on the Earth Observing System (EOS)–Aqua satellite (AMSR-E). The WRF models’ ability to accurately simulate the SST-induced surface wind response is demonstrated from a comparison with satellite surface wind observations from the SeaWinds scatterometer on the Quick Scatterometer (QuikSCAT) satellite. Relevant features of this simulation include a quasi-periodic distribution of mesoscale SST perturbations with spatial scales ~200 km and strong winds that lead to a large surface sensible heat flux response, whose broad range of 80–100 W m⁻² between warm and cool SST perturbations is much larger than seen in most previous simulations of mesoscale wind–SST coupling. This simulation provides the first realistic example of vertical turbulent redistribution of momentum driven by the SST-induced surface heating perturbations acting in concert with the SST-induced pressure gradients to accelerate near-surface flow toward warm water and decelerate near-surface flow toward cool water. This simulation is also the first example of a near-surface wind speed response to mesoscale SST perturbations that differs qualitatively and substantially from the vertically averaged MABL wind response. In the vertically averaged MABL momentum budget, the surface wind stress acts as a drag on the SST-induced perturbation flow as it is being accelerated by SST-induced pressure gradients. However, only in the middle and upper reaches of the MABL does the turbulent stress divergence act as a drag on the SST-induced winds perturbations in this simulation. These mesoscale SST perturbations are also shown to modify the wind direction within the MABL. Dynamically, this is accomplished through SST-induced perturbations to the crosswind components of the pressure gradient, turbulent stress divergence, and the Coriolis force. Title: Dynamical Analysis of the Boundary Layer and Surface Wind Responses to Mesoscale SST Perturbations Author: Chelton, Dudley B., Thum, Nicolai, Samelson, Roger M., O’Neill, Larry W., Esbensen, Steven K. The dynamical response of the marine atmospheric boundary layer (MABL) to mesoscale sea surface temperature (SST) perturbations is investigated over the Agulhas Return Current during winter from a 1-month, high-resolution, three-dimensional simulation using the Weather Research and Forecasting (WRF) mesoscale model. A steady lower boundary condition for July 2002 is obtained using SST measurements from the Advanced Microwave Scanning Radiometer on the Earth Observing System (EOS)–Aqua satellite (AMSR-E). The WRF models’ ability to accurately simulate the SST-induced surface wind response is demonstrated from a comparison with satellite surface wind observations from the SeaWinds scatterometer on the Quick Scatterometer (QuikSCAT) satellite. Relevant features of this simulation include a quasi-periodic distribution of mesoscale SST perturbations with spatial scales ~200 km and strong winds that lead to a large surface sensible heat flux response, whose broad range of 80–100 W m⁻² between warm and cool SST perturbations is much larger than seen in most previous simulations of mesoscale wind–SST coupling. This simulation provides the first realistic example of vertical turbulent redistribution of momentum driven by the SST-induced surface heating perturbations acting in concert with the SST-induced pressure gradients to accelerate near-surface flow toward warm water and decelerate near-surface flow toward cool water. This simulation is also the first example of a near-surface wind speed response to mesoscale SST perturbations that differs qualitatively and substantially from the vertically averaged MABL wind response. In the vertically averaged MABL momentum budget, the surface wind stress acts as a drag on the SST-induced perturbation flow as it is being accelerated by SST-induced pressure gradients. However, only in the middle and upper reaches of the MABL does the turbulent stress divergence act as a drag on the SST-induced winds perturbations in this simulation. These mesoscale SST perturbations are also shown to modify the wind direction within the MABL. Dynamically, this is accomplished through SST-induced perturbations to the crosswind components of the pressure gradient, turbulent stress divergence, and the Coriolis force. Close

• 4. [Article] Satellite Observations of Mesoscale Eddy-Induced Ekman Pumping

  This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://journals.ametsoc.org/loi/phoc.

  Citation × Citation Citation Abstract Copy Title: Satellite Observations of Mesoscale Eddy-Induced Ekman Pumping Author: Gaube, Peter, Chelton, Dudley B., Schlax, Michael G., Samelson, Roger M., O'Neill, Larry W. This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://journals.ametsoc.org/loi/phoc. Title: Satellite Observations of Mesoscale Eddy-Induced Ekman Pumping Author: Gaube, Peter, Chelton, Dudley B., Schlax, Michael G., Samelson, Roger M., O'Neill, Larry W. This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://journals.ametsoc.org/loi/phoc. Close