Climatology of the Nordic (Irminger, Greenland, Barents, Kara and White/Pechora) Seas ice cover based on 85 GHz satellite microwave radiometry: 1992-2008

摘要

The ice cover of the Arctic peripheral seas bordering the Northern North Atlantic is examined for 1992-2008 using the ARTIST Sea Ice (ASI) algorithm applied to derive the sea ice concentration from 85 GHz SSM/I measurements. Our analysis reveals a 2 months longer ice-free season in the Irminger Sea (IS), and reductions in ice area and extent between 1992-1999 and 2000-2008 by 10-20% during winter and 30-55% in summer. Barents Sea (BS) ice-cover anomalies (ICA) persist twice as long as ICA in the other regions. Early winter ICA in region IS are correlated to late summer/fall Greenland Sea (GS) ICA. Summertime GS and wintertime IS ICA are correlated to winter Fram Strait ice-area flux anomalies. The wintertime GS ice-cover decrease is associated with less Is Odden events. Our analysis suggests a large-scale, interregional ocean-ice-atmosphere feedback mechanism involving regions BS, Kara (KS) and White/Pechora Sea (WPS). To understand this mechanism the current and preceding general atmospheric circulation, associated variations in Arctic Ocean ice export and oceanic heat advection are needed. However, our results suggest (1) BS ICA could play a key role to predict subsequent KS ICA and (2) anomalous Arctic Ocean ice export into BS could trigger long-lasting BS ICA.