HR: 0800h
AN: A21B-0731    [Abstracts]
TI: Anomalous Vortex Intensification and Associated Stratosphere-Troposphere Evolution
AU: * Limpasuvan, V
EM: var@coastal.edu
AF: Coastal Carolina University, Dept. of Chemistry and Physics, Conway, SC 29526
AU: Jeev, K
EM: kjeev@coastal.edu
AF: John Hopkins University, Dept. of Earth and Planetary Sciences, Baltimore, MD 21218
AU: Hartmann, D L
EM: dennis@atmos.washington.edu
AF: University of Washington, Dept. of Atmospheric Sciences, Seattle, WA 98195
AU: Yung, Y L
EM: yly@mercu1.gps.caltech.edu
AF: California Institute of Technology, Dept. of Geological and Planetary Sciences, Pasadena, CA 91125
AB: Composite stratosphere-troposphere evolution is observed during the Northern Hemisphere extended winters in association with stratospheric polar vortex intensification events. These events are initially marked by the descent of zonal wind and temperature anomalies from the upper stratosphere to the tropopause, in connection with strong anomalous heat fluxes in the upper stratosphere. As the events mature, enhanced anomalous momentum fluxes appearing in the upper troposphere accompany an increase in the amplitude of the Northern Hemisphere Annular Mode and related wind and temperature anomalies near the surface. Overall, the observed dynamics exhibit a largely linear relationship (similar, but opposite in sign) to those found during stratospheric polar vortex weakening events (as characterized by Sudden Stratospheric Warming). However, notable differences occur in the tropical region. In particular, anomalous vortex intensification tends to coincide with La Nina events.
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3362 Stratosphere/troposphere interactions
DE: 1610 Atmosphere (0315, 0325)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting