Coupled Air-Sea Interactions in the Southeast Pacific

Dian Putrasahan (Scripps Institution of Oceanography, UCSD)
Art Miller (Scripps Institution of Oceanography, UCSD)
Hyodae Seo (International Pacific Research Center, University of Hawaii, Manoa)


We examine the air-sea interactions in the Humboldt Current System (HCS) using the Scripps Coupled Ocean-Atmosphere Regional (SCOAR) model. The oceanic component for this model uses Regional Ocean Modeling System (ROMS) and the atmospheric component uses the Regional Spectral Model (RSM). Recent studies based on satellite observations suggest that there is a tight coupling between summertime SST gradients and wind stress derivatives, and the SCOAR model has reproduced many aspects of the observed coupled processes. In this study, we are comparing the HCS wind stress and SST fields in SCOAR to those obtained from satellite observations such as QuikSCAT and TMI-AMSRE, and are also diagnosing the coupled processes that occur between the surface flux fields and the SSTs. We are examining the correspondence between the crosswind SST gradient and wind stress curl, along with the downwind SST gradient and wind stress divergence, in both the SCOAR model and NCEP/DOE Reanalysis II. Particular emphasis is being given to the effect of atmospheric feedback processes onto the stability of the coastal upwelling and understanding the processes that control the mean and eddy circulation in the HCS, which contributes to the overall heat balance in the upper ocean and the resulting mean ocean-atmosphere circulation of the Eastern Tropical Pacific region.