HR: 15:15h
AN: A43G-06    [Abstracts]
TI: Winter Cyclone Activity in the Northern North Atlantic: Observational Analysis
AU: * Tsukernik, M
EM: tsukerni@nsidc.org
AF: National Snow and Ice Data Center (NSIDC), University of Colorado Campus Box 449, Boulder, CO 80309 United States
AU: Serreze, M
EM: serreze@nsidc.org
AF: National Snow and Ice Data Center (NSIDC), University of Colorado Campus Box 449, Boulder, CO 80309 United States
AU: Kindig, D
EM: kindig@nsidc.org
AF: National Snow and Ice Data Center (NSIDC), University of Colorado Campus Box 449, Boulder, CO 80309 United States
AB: The northern North Atlantic is one of the most synoptically active and variable regions of the planet, especially during the winter season. The region encompassing the Icelandic Low (IL) can be broadly thought of as the terminus of the North Atlantic cyclone track. Regional cyclone development processes are important. These include the presence of strong temperature contrasts between the open ocean and adjacent cold sea ice/snow covered surfaces, large gradients in sea surface temperature (SST) and vorticity production in the lee of the southern Greenland. Cyclone activity in this area plays a key role in the Arctic's heat budget through the poleward transport of moist static energy. Through impacts on net precipitation over the Arctic Ocean and wind and ocean current driven export of sea ice via Fram Strait, these cyclones also modulate Arctic's freshwater budget. The objective of our study is to examine regional cyclone development processes and better elucidate their role in Arctic climate. NCEP reanalysis data are used to examine winter cyclone activity for the period 1979- 1999. We identify several regions where strong deepening (>6hPa/6h) and/or cyclogenesis tends to be preferred. Areas of strong deepening include the region encompassing the mean IL, a region near Svalbard corresponding to the northernmost penetration of ice-free ocean and a region to the southwest of Greenland where there are large SST gradients. Cyclogenesis is most common near the locus IL. A number of these events represent lee-side cyclogenesis. Deepening and development processes are evaluated though composite analysis and case studies. Various NCEP fields, including sea level pressure, 500 hPa heights, surface and lower tropospheric temperatures and vertical motion are assessed.
DE: 0312 Air/sea constituent fluxes (3339, 4504)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3349 Polar meteorology
DE: 3364 Synoptic-scale meteorology
DE: 4540 Ice mechanics and air/sea/ice exchange processes (0700, 0750, 0752, 0754)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005