GFI/BCCR Seminar: Extratropical Air-Sea Interactions: Kuroshio Eddies, Pacific Storm Track and Climate Variability

Ping Chang (Texas A&M University, Department of Oceanography, US):

Extratropical Air-Sea Interactions: Kuroshio Eddies, Pacific Storm Track and Climate Variability

Abstract
Eddy-rich western boundary current regimes, such as the Kuroshio and Gulf Stream Extension regions, have been identified as key locations in the extratropics where SST variability may provide an important source of energy for driving atmospheric variability.

In this talk, we present high-resolution regional climate modeling results, supported by observational analyses, that the rectified effects of meso-scale SST variability, largely confined in the Kuroshio-Oyashio confluence region (KOCR), can exert a significant remote influence on winter rainfall variability along the U. S. Northern Pacific coast. Warm ocean eddies punctuate atmospheric planetary boundary layer, moistening and destabilizing the lower atmosphere, which in turn affects the North Pacific storm track through impacts on cyclogenesis.

We further show that the ocean mesoscale eddy atmosphere (OMEA) feedback plays an important role in maintaining the sharp SST gradient along the Kuroshio Extension. These findings point to the need to improve the representation of ocean mesoscale eddies and their feedbacks with the atmosphere in climate models.