P2.3
Middle atmospheric influences of very large Solar Proton Events in Solar Cycle 23
Charles H. Jackman, NASA/GSFC, Greenbelt, MD; and D. R. Marsh, F. M. Vitt, R. R. Garcia, E. L. Fleming, and G. J. Labow
A solar variability involving energetic solar protons precipitating on the Earth's atmosphere can lead to short- and long-term constituent changes. Middle atmospheric influences of solar proton events (SPEs) have been observed and modeled. UARS HALOE; Envisat's MIPAS, SCIAMACHY, and GOMOS; and EOS MLS have all observed significant constituent changes in the past several years as a result of SPEs. The Whole Atmosphere Community Climate Model (WACCM) has also been used to study the SPE-caused middle atmospheric influences. Polar middle atmospheric effects of SPEs measured by satellite instruments will be compared with WACCM predictions in this paper. An especially active period of very large SPEs (e.g., July and November 2000, November 2001, and October/November 2003) occurred in Solar Cycle 23 and impacted the middle atmospheric polar cap regions. The SPE-caused ionization, as well as dissociation processes, led to the production of HOx (H, OH, HO2) and NOy (N, NO, NO2, NO3, HNO3, HO2NO2, N2O5, ClONO2, BrONO2). Substantial (>40%) short-lived mesospheric ozone decreases followed these enhancements of HOx and NOy and significant (>10%) stratospheric ozone changes continued for months beyond the very largest SPEs due to the long-lived NOy. The long-term SPE-caused polar ozone effects (both decreases and increases) after these very disturbed periods produced stratospheric temperature changes up to 2K.
Poster Session 2, Long-Term Change in Middle Atmosphere and the Impact of Solar Variability: Poster
Tuesday, 21 August 2007, 1:30 PM-3:30 PM, Holladay
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