HR: 1340h
AN: A13E-1601 [WITHDRAWN]    [Abstracts]
TI: Storm Track Variability and Interaction with the Mean Flow on Daily, Interannual and Climate Change Time Scales
AU: * Wettstein, J J
EM: justinjw@atmos.washington.edu
AF: University of Washington, Dept. of Atmospheric Sciences Box 351640, Seattle, WA 98195, United States
AU: Wallace, J M
EM: wallace@atmos.washington.edu
AF: University of Washington, Dept. of Atmospheric Sciences Box 351640, Seattle, WA 98195, United States
AB: "Pulsing" and "latitudinal shifting" modes of extratropical storm track variance are identified as fundamental modes of climate variability in the storm track basins of both the Northern and Southern Hemisphere. The secondary latitudinal shifting modes of storm track variability can be related to well-known modes of atmospheric flow variability, such as the Northern Annular Mode / North Atlantic Oscillation, Pacific North America pattern and the Southern Annular Mode. The dominant pulsing modes of storm track variability have received somewhat less attention in terms of their relationship to the mean atmospheric flow. At month-to-month and interannual time scales, pulsing and shifting modes of storm track variability are related to zonal wind anomalies that are consistent with anticipated forcing by the eddy-induced momentum fluxes. At day- to-day time scales, there is some indication that the pulsing mode of storm track variability may evolve into the shifting mode of storm track variability--resulting in wind anomalies consistent with the patterns of atmospheric flow variability previously described. At climate change time scales, extratropical storminess appears to be strongly suppressed in cold climates and moderately enhanced in warm climates, relative to the modern day in a fully-coupled general circulation model's output from Last Glacial Maximum, modern day and quadrupled carbon dioxide experiments. Observations from the Northern Hemisphere Pacific and especially throughout the Southern Hemisphere seem to indicate a recent intensification of the storm tracks geographically consistent with the general circulation model output.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1620 Climate dynamics (0429, 3309)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3319 General circulation (1223)
DE: 4215 Climate and interannual variability (1616, 1635, 3305, 3309, 4513)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting