Collaborative Research: Coupled Ocean-Atmosphere Feedbacks Affecting California Coastal Climate: Current Conditions and Future Projections

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

The coastal climate of California is profoundly affected by the ocean, which moderates its hot summers and provides moisture for much-needed winter rains. Sea surface temperature (SST) anomalies and ocean surface current anomalies, ranging from the meso-to-frontal scales of cool coastal upwelling to the regional-to-basin scales of the marine heat waves, are inherently coupled with the atmosphere. This study focuses on the fundamental coupled ocean-atmosphere feedback processes that affect the climate, weather, and upwelling along the coast. The project will use numerical models of the coupled ocean-atmosphere system to improve understanding of the ocean-atmosphere interactions, including with land and mountains, for coastal California. In addition, it will examine the effects on climate of coastal California under projected future greenhouse-gas-forced changes. This project will quantify the effects of ocean-atmosphere boundary layer coupling on California coastal regions using a series of regional high-resolution coupled ocean-atmosphere model simulations, including full ocean-atmosphere coupling and well-resolved orography and land-sea distribution. These will include ensembles of 10-year long runs forced by observed current climate and projected future climate boundary conditions, as well as ensembles of runs initialized under observed marine heat wave conditions. The model runs will be used to study how the statistics of daily, intraseasonal and interannual variability in the atmosphere and the oceanic upwelling field, are affected by the anomalous ocean-atmosphere conditions associated with eddies, fronts, and extreme SST anomalies, and assess how they may be altered by changes in large-scale atmospheric and oceanic drivers associated with global warming. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.