HR: 16:30h
AN: SA34A-03 INVITED    [Abstracts]
TI: Modeling the Chemical and Dynamical Response of the Whole Atmosphere to Energetic Particle Precipitation
AU: * Marsh, D R
EM: marsh@ucar.edu
AF: National Center for Atmospheric Research, Atmospheric Chemistry Division, P.O. Box 3000, Boulder, CO 80307-3000, United States
AU: Kinnison, D E
EM: dkin@ucar.edu
AF: National Center for Atmospheric Research, Atmospheric Chemistry Division, P.O. Box 3000, Boulder, CO 80307-3000, United States
AU: Vitt, F M
EM: fvitt@ucar.edu
AF: National Center for Atmospheric Research, Atmospheric Chemistry Division, P.O. Box 3000, Boulder, CO 80307-3000, United States
AU: Garcia, R R
EM: rgarcia@ucar.edu
AF: National Center for Atmospheric Research, Atmospheric Chemistry Division, P.O. Box 3000, Boulder, CO 80307-3000, United States
AU: Jackman, C H
EM: Charles.H.Jackman@nasa.gov
AF: NASA Goddard Space Flight Center, Code 613.3, Greenbelt, MD 20771, United States
AB: Investigations into the role of the middle and upper atmosphere on climate have led to development of coupled chemistry climate models that extend in altitude to the mesosphere and lower thermosphere. These models are now being used to investigate the importance of variable solar and geomagnetic forcing on composition and dynamics throughout the whole atmosphere.This study reviews investigations into the influence of energetic particle precipitation (EPP) on stratospheric composition and dynamics, and presents analysis of simulations using NCAR's Whole Atmosphere Community Climate Model (WACCM). We find ionization from EPP in the polar regions during the declining phase of solar cycle 23 lead to significant increases in the concentration of hydrogen and nitrogen species. This period was remarkable in that it included a series of large solar proton events (SPEs). Analysis of an ensemble of WACCM simulations indicates that SPEs affect ozone chemistry either directly via increased catalytic loss from the enhanced hydrogen and nitrogen species, or indirectly from perturbations to active chlorine and bromine partitioning. In the stratosphere, ozone and temperatures changes can persist for months following an SPE and are not restricted to the region where SPE ionization occurred.
DE: 0335 Ion chemistry of the atmosphere (2419, 2427)
DE: 0340 Middle atmosphere: composition and chemistry
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3337 Global climate models (1626, 4928)
DE: 3369 Thermospheric dynamics (0358)
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting