A41C-0080
The impact of poleward moisture and sensible heat flux on Arctic winter sea-ice variability.
Thursday, 17 December 2015
Poster Hall (Moscone South)
Hyo Seok Park1, Sukyoung Lee2, Seok-Woo Son3, Steven B Feldstein2 and Yu Kosaka4, (1)Scripps Institution of Oceanography, La Jolla, CA, United States, (2)Pennsylvania State University Main Campus, University Park, PA, United States, (3)Seoul National University, Seoul, South Korea, (4)University of Tokyo, Bunkyo-ku, Japan
Abstract:
The surface warming in recent decades has been most rapid in the Arctic, especially during the winter. Here, by utilizing global reanalysis and satellite datasets, we show that the northward flux of moisture into the Arctic during the winter strengthens the downward infrared radiation (IR) by 30–40 W m-2 over 1–2 weeks. This is followed by a decline of up to 10% in sea ice concentration over the Greenland, Barents and Kara Seas. A climate model simulation indicates that the wind-induced sea-ice drift leads the decline of sea-ice thickness during the early stage of the strong downward IR events, but that within one week the cumulative downward IR effect appears to be dominant. Further analysis indicates that strong downward IR events are preceded several days earlier by enhanced convection over the tropical Indian-western Pacific Ocean. This finding suggests that sea-ice predictions can benefit from an improved understanding of tropical convection and ensuing planetary wave dynamics.
