HR: 13:45h
AN: A43G-01 INVITED     [Abstracts]
TI: Seasonal and Regional Aspects of Northern High Latitude Cyclone Activity
AU: * Serreze, M C
EM: serreze@kryos.colorado.edu
AF: CIRES/NSIDC, Campus Box 449, University of Colorado, Boulder, CO 80309-0449 United States
AB: Northern high latitude cyclone activity exhibits pronounced seasonal, regional and inter-annual variability. During winter, the North Atlantic storm track extends well into the Arctic, associated with large poleward heat and moisture transports. Cyclone activity peaks in the vicinity Icelandic Low (IL). While the strength and location of the IL is strongly allied with the phase of the well-known North Atlantic Oscillation, regional development processes are important. The high frequency of cyclogenesis and system deepening in this region reflects orographic influences of Greenland (e.g., lee-side development and bifurcation of systems migrating from the south) and strong sea surface temperature gradients, particularly along the sea ice margin. The IL and North Atlantic storm track weaken in summer, but cyclone activity increases over Arctic land areas and the central Arctic Ocean. Summer cyclogenesis tends to be focused along the Arctic frontal zone, most strongly developed along the shores of eastern Siberia and Alaska. The summer Arctic frontal zone appears to arise from strong heating contrasts along the sea ice/land margin. Coastal orography helps to sharpen the baroclinicity. Systems generated along the frontal zone tend to migrate into the central Arctic Ocean, where they occlude and stall. Recent decades have seen a general increase in northern high latitude cyclone activity.
DE: 0750 Sea ice (4540)
DE: 1840 Hydrometeorology
DE: 3349 Polar meteorology
DE: 3364 Synoptic-scale meteorology
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005