Subarctic and Arctic sea surface temperature and its relation to ocean heat content 1982-2010

Abstract

This is an examination of SST variability in the Subarctic and Arctic during the 29 year period 1982-2010, based primarily on data from the Pathfinder AVHRR data set as well as operational SST products from NOAA and the UK Meteorological Office. A goal is to explore the connection between SST variations in the subpolar gyres and SST variations further north, with emphasis on the Nordic Seas because of their atmospheric exposure and connection to the overturning circulation. After identifying and correcting for biases in Pathfinder AVHRR (also present in the operational products) the seasonal cycle and 29-year warming trend is described. The analysis shows that much of the warming of the North Atlantic subpolar gyre during the period occurred in 1990s and compensated for cooling during the decades of the early 1960s to mid-1990s in this same region. Superimposed on this warming trend the analysis reveals a succession of residual SST anomalies with 0.5C amplitudes that seem to move out of the North Atlantic subpolar gyre into the Nordic Seas following the North Atlantic and Norwegian Currents. Within the Nordic Seas these SST anomalies slowly advect in a counterclockwise direction. After approximately six years part of the anomalies exits the Nordic Seas through the East Greenland Current. The connection between these SST anomalies and underlying anomalies of 0/300 m heat content is discussed. The existence of these SST anomaliesand their origin at lower latitudes highlights the importance of ocean exchanges in influencing Arctic climate. © 2012 American Geophysical Union. All Rights Reserved.