HR: 11:25h
AN: SA12A-04 INVITED     [Abstracts]
TI: Recent impacts of energetic particle precipitation on the Earth's middle atmosphere
AU: * Randall, C E
EM: randall@lasp.colorado.edu
AF: University of Colorado, LASP, UCB 392, Boulder, CO 80309-0392 United States
AB: The extraordinary solar storms of October-November 2003 have now received much attention in the literature, and it is well-known that the associated energetic particles caused immediate production of HOx and NOx in the upper stratosphere and mesosphere that led to significant ozone depletion. Less obvious is whether unprecedented enhancements in stratospheric NOx and concurrent reductions in ozone several months following the storms were a direct result of the storms themselves, or of energetic particle precipitation later in the winter. Complicating the picture is the fact that the late winter upper stratospheric polar vortex in 2004 was stronger than previously observed since records began (1979). Insight to this dilemma can be gained by comparison of atmospheric effects after other periods of high geomagnetic activity, and in both hemispheres. Using satellite data and modeling, this presentation will compare and contrast the response of the middle atmosphere after several different periods of high geomagnetic activity in recent years. Emphasis will be placed on understanding the effects after the late 2003 storms in the context of storms that occurred at similar times of year relative to the northern and southern hemispheres; this will include, for instance, the solar proton events of October 1989 and November 2000 and 2001, and the solar storms of April 2002.
DE: 0342 Middle atmosphere--energy deposition
DE: 2716 Energetic particles, precipitating
DE: 3360 Remote sensing
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly