Rapport Klima 7, 2002

Rasmus E Benestad, Inger Hanssen-Bauer, Torill Engen Skaugen and Eirik J Førland:

Associations between the sea-ice and the local climate on Svalbard

The role of sea-ice for the local climate in the Svalbard region is investigated using observed temperature records from Arctic climate stations and gridded sea-ice data. The coupling between sea-ice and sea level pressure as well as 2-meter temperature is also examined. The quality of the sea-ice product from the HadISST1.1 project is evaluated in relation with variations in the sea level pressure, 2-meter temperature fields, and observed temperatures at Arctic climate stations. Furthermore, the gridded sea-ice analysis is compared with the 1990's climate described by 3 atmospheric-oceanic general circulation models. The analysis indicates that there is a close connection between the sea-ice extent and the local climate in the vicinity of Svalbard. The land temperature is sensitive to the location of the ice-edge. The good fit between the sea-ice and other climate variables since 1950 indicates that the sea-ice product is accurate for this recent period. But there are indications of severe degradation of the sea-ice data quality prior to the 1950s. The reduction in the quality is attributed to sparse observations. The comparison between 3 state-of-the-art climate models shows that there are important differences in their description of the Arctic climate, with a more than 10o difference in the location of the ice edge

Key words: Svalbard; sea-ice; temperature; canonical correlation analysis; step-wise regression; model evaluation