HR: 17:40h
AN: OS34A-07 INVITED     [Abstracts]
TI: Increased Heat Transport into the Arctic Ocean in a Climate Model of the 21st Century
AU: * Bitz, C M
EM: bitz@apl.washington.edu
AF: University of Washington Polar Science Center, Box 355640, Seattle, WA 98195-5640 United States
AU: Woodgate, R A
EM: woodgate@apl.washington.edu
AF: University of Washington Polar Science Center, Box 355640, Seattle, WA 98195-5640 United States
AB: Recently Holland and Bitz (2003) showed that most global climate models predict an increase in the northward oceanic heat transport north of about 60N in future climate scenarios compared to present day. This increase in heat transport is reminiscent of explanations posed for the recently observed warming in the Atlantic layer in the Eurasian Basin of the Arctic Ocean. An implication is that warmings like those that occurred in the recent past, which have been attributed to wind variations by some, could also occur in the future due to greenhouse gas forcing. This may seem surprising because the North Atlantic Meridional Overturning Circulation (MOC) decreases in most future climate scenarios (IPCC 2001). Our analysis of one model, the Community Climate System Model Version 3, shows that, although in future scenarios the MOC becomes shallower and weaker south of about 60N, it strengthens into the Nordic Seas and Arctic Ocean. This increased flow near the surface carries warmer water than present into the Arctic. We present evidence to argue that the increase in MOC and heat transport into the Arctic in future scenarios with the model is in response to the transition from perennial to firstyear ice in the Barents Sea and Arctic Ocean, and the attendant increase in heat loss and brine rejection in fall and winter.
DE: 4207 Arctic and Antarctic oceanography
DE: 4215 Climate and interannual variability (3309)
DE: 4219 Continental shelf processes
DE: 4540 Ice mechanics and air/sea/ice exchange processes
DE: 1635 Oceans (4203)
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting