North Pole Environmental Observatory delivers early results

Abstract

Scientists have argued for a number of years that the Arctic may be a sensitive indicator of global change, but prior to the 1990s, conditions there were believed to be largely static. This has changed in the last 10 years. Decadal‐scale changes have occurred in the atmosphere, in the ocean, and on land [ Serreze et al ., 2000]. Surface atmospheric pressure has shown a declining trend over the Arctic, resulting in a clockwise spin‐up of the atmospheric polar vortex. In the 1990s, the Arctic Ocean circulation took on a more cyclonic character, and the temperature of Atlantic water in the Arctic Ocean was found to be the highest in 50 years of observation [ Morison et al ., 2000]. Sea‐ice thickness over much of the Arctic decreased 43% in 1958–1976 and 1993–1997 [ Rothrock et al., 1999 ].