Coastal climate and upwelling

There is controversy in assessing future climate in the coastal band over the land and coastal waters. The expected increase of the global surface temperature over the land might not be fully valid in coastal regions and there are observational studies that indicate cooling of the coastal band over the land. Some studies of the coastal sea surface temperature indicate cooling of the surface coastal ocean while others show possible warming. One of the problems in investigating these results lies in the spatial inhomogeneity of the coastal ocean and adjacent marine atmospheric boundary layer. By using surface and buoy observations on the U.S. West Coast as well as regional climate modeling with 12 km horizontal resolution for the historical period and future scenarios, this study focuses on understanding weather and climate characteristics of the coastal environment and investigating future projections that might have an impact on the coupled atmosphere-ocean processes. The study also indicates that the variability within the same type of ENSO indices additionally influence coastal flows and ocean circulations. In particular, different zonal positions of the sea surface temperature anomaly pool during ENSO episodes have strong impact on the development and evolution of the coastal upwelling. Modulation of upwelling will have a significant impact on nutrients, productivity and venting CO2 back to the atmosphere. Improved understanding and prediction of coastal upwelling will lead to better operational forecasts of surface temperature in coastal regions as well as to proper treatment of this process in climate predictions.