EESS Winter Seminar Series - LuAnne Thompson, Professor, School of Oceanography, University of Washington
EESS Winter Seminar Series - LuAnne Thompson, Professor, School of Oceanography, University of Washington, "Ocean forcing of the atmosphere in the North Atlantic Basin: a perspective from satellite observations", Abstract: The ocean acts to buffer changes in the climate system with the upper 800m of the ocean taking up more than 90% of the excess heat in the climate system. The ocean also plays an important role in transporting heat from the equator to the poles with poleward oceanic heat transport maximum near 30N. Over the last several decades, the potential role of changes in the Atlantic Meridional Overturning Circulation in heat delivery to the subpolar North Atlantic has been the focus of research. However, much of the heat brought from the tropics is released to the atmosphere at the latitude of the Gulf Stream. Here, we examine whether locally stored heat can influence the atmosphere in the North Atlantic Basin. With the satellite record of SSH (sea surface height) now 20 years long, and because regionally SSH can act as a proxy for ocean heat content, we examine whether SSH gives us additional information that is not present in other observation records. By calculating the correlations between SSH and surface heat flux for each month of the year, we find that SSH locally predicts surface flux one to three seasons in advance. The regions of high predictive skill are located primarily within the Florida Current/North Gulf Stream and North Atlantic Current systems, and these regions may be linked to specific features in cloud properties, suggesting that the impact of ocean heat changes could lead to changes in radiative forcing and to atmospheric circulation. This analysis suggests that SSH can be used as an additional tool for predicting North Atlantic climate on interannual times scales. In addition, we show that the oceanʼs influence on North Atlantic climate should be examined regionally and that basin-wide metrics may miss the mechanisms that control how the ocean and atmosphere interact in the mid-latitudes.