HR: 1340h
AN: A33D-0939    [Abstracts]
TI: Modeling Characteristics of Winter Cyclone Activity in the Northern North Atlantic
AU: * Kindig, D N
EM: kindig@nsidc.org
AF: National Snow and Ice Data Center, 449 UCB, University of Colorado UCB 449, Boulder, CO 80309-0449 United States
AU: Tsukernik, M
EM: tsukerni@kryos.colorado.edu
AF: National Snow and Ice Data Center, 449 UCB, University of Colorado UCB 449, Boulder, CO 80309-0449 United States
AU: Serreze, M C
EM: serreze@coriolis.colorado.edu
AF: National Snow and Ice Data Center, 449 UCB, University of Colorado UCB 449, Boulder, CO 80309-0449 United States
AU: Serreze, M C
EM: serreze@coriolis.colorado.edu
AF: CIRES, University of Colorado at Boulder Main Campus 216 UCB-Room 318, Boulder, Co 80309-216 United States
AB: The region to the southeast of Greenland corresponds with the location of the Icelandic Low (IL). The IL and surrounding region has important influences on the transport of moist static energy into the Arctic that is required to balance the high-latitude radiation deficit at the top of the atmosphere. Cyclones act as a transport mechanism for the Arctic's freshwater budget, particularly through their impacts on net precipitation over the Arctic Ocean and the wind and ocean current driven export of sea ice and low salinity waters out of the Arctic via Fram Strait. Cyclones in the region are affected by low level thermal contrasts between the relatively warm high-latitude ocean and adjacent cold sea ice and land, and the effect of Greenland's position downstream of the primary eastern North American longwave trough, which promotes strong synoptic development in its lee. The objective of our study is to examine some of these regional cyclone lifecycle processes, with the aim of elucidating their role in Arctic's heat and freshwater budgets. We make use of the MM5 regional climate model. This complements parallel observational studies using information from the NCEP reanalysis. On the basis of NCEP data, we identified several key regions, where strong deepening and/or cyclogenesis occur. Several cyclone case studies were selected. These include both cyclones that move into the region surrounding Greenland and those that develop in the waters east of Greenland. Using MM5, these cases are subjected to a variety of sensitivity studies involving vertical and horizontal resolution of Greenland and the location of the sea ice margin. Important development processes include enhancement of low-level baroclinicity along the sea ice margin, large gradients in sea surface temperature, and vorticity production in the eastern lee of Greenland. As shown from studies in which we remove the topography of Greenland,the orographic barrier of the ice sheet has remarkable impacts on both the tracks and intensity of systems. Greenland therefore appears to be a key factor in determining patterns of heat and moisture transports into the Arctic.
DE: 0750 Sea ice (4540)
DE: 0774 Dynamics
DE: 0798 Modeling
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005