HR: 16:20h
AN: U44A-02    [Abstracts]
TI: An Ice Free Arctic?
AU: * Tremblay, B
EM: tremblay@ldeo.columbia.edu
AF: Lamont Doherty Earth Observatory of Columbia University, 61 Rt 9W, Palisades, NY 10964-8000 United States
AU: Newton, R
EM: bnewton@ldeo.columbia.edu
AF: Lamont Doherty Earth Observatory of Columbia University, 61 Rt 9W, Palisades, NY 10964-8000 United States
AU: Cullather, R
EM: cullat@ldeo.columbia.edu
AF: Lamont Doherty Earth Observatory of Columbia University, 61 Rt 9W, Palisades, NY 10964-8000 United States
AB: A decrease in the Arctic sea ice cover of 2.9% per decade has been observed in the last decades, particularly in summer. There is presently a lot of speculation in the scientific community that the Arctic may actually become seasonally ice free as global warming continues. Mechanisms that could be responsible for an ice-free Arctic Ocean are presented. In particular the relative importance of 1- increased downwelling longwave radiation, 2- changes in the atmospheric circulation, and 3- increased vertical ocean heat transport (all potentially associated with an increase in the greenhouse gas concentration) in shaping an ice-free Arctic are discussed. To this end, present-day and future climates simulated by several coupled general circulation models from the Intergovernmental Panel on Climate Change simulations (IPCC-2005) are investigated. Strength and weaknesses of these models are discussed in the light of recent satellite observations and hydrograhic data from the Arctic. Results from a stand-alone sea-ice model where each individual atmospheric fields can be varied individually, are also presented to help in the interpretation of the coupled model results.
DE: 0738 Ice (1863)
DE: 1863 Snow and ice (0736, 0738, 0776, 1827)
SC: Union [U]
MN: Fall Meeting 2005