HR: 1340h
AN: SA23A-1129    [Abstracts]
TI: Interannual variability in the effects of energetic particle precipitation (EPP) on the stratosphere
AU: * Randall, C E
EM: randall@lasp.colorado.edu
AF: LASP/Univ Colorado, 392 UCB, Boulder, CO 80309, United States
AU: Bailey, S M
EM: scott.m.bailey@vt.edu
AF: Virginia Tech, 302 Whittemore Hall, Blacksburg, VA 24061,
AU: Bernath, P F
EM: pfb500@york.ac.uk
AF: University of Waterloo, Dept. of Chemistry, Waterloo, ON N2L3G1, Canada
AU: Fang, X
EM: fang@lasp.colorado.edu
AF: LASP/Univ Colorado, 392 UCB, Boulder, CO 80309, United States
AU: Harvey, V L
EM: harvey@lasp.colorado.edu
AF: LASP/Univ Colorado, 392 UCB, Boulder, CO 80309, United States
AU: Liu, H
EM: liuh@ucar.edu
AF: NCAR/HAO, P.O. Box 3000, Boulder, CO 80307, United States
AU: Holt, L
EM: holt@lasp.colorado.edu
AF: LASP/Univ Colorado, 392 UCB, Boulder, CO 80309, United States
AU: Marsh, D R
EM: marsh@ucar.edu
AF: NCAR/ACD, P.O. Box 3000, Boulder, CO 80307, United States
AU: Russell, J M
EM: james.russell@hamptonu.edu
AF: Hampton University, Center for Atmospheric Sciences, Hampton, VA 23668,
AU: Siskind, D E
EM: david.siskind@nrl.navy.mil
AF: Naval Research Laboratory, Code 7640 4555 Overlook Ave, S. W., Washington, DC 20375, United States
AB: Odd nitrogen produced routinely in the mesosphere or lower thermosphere (MLT) by low- or medium-energy particles, or sporadically in the stratosphere by very high energy electrons or solar protons, can affect stratospheric ozone distributions. This talk focuses on the magnitude and variability of the contribution of EPP- NOx (odd nitrogen produced by EPP) to the stratosphere during the last two decades. New results from meteorological analyses, satellite-based observations, and 3D model simulations will be presented. We will show that interannual variations in the amount of EPP-NOx in the southern hemisphere stratosphere depend primarily on variability in energetic particle precipitation. In the northern hemisphere, however, meteorological variability appears to be more significant. Observations suggest that EPP contributes up to about 40 percent (10 percent) of the polar (hemispheric) NOx source in the stratosphere. We will highlight some of the gaps in our understanding of the pathways by which coupling between the stratosphere and MLT is affected by EPP, and the need for observations of NOx throughout the MLT in the polar winter.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0340 Middle atmosphere: composition and chemistry
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
DE: 0342 Middle atmosphere: energy deposition (3334)
DE: 2716 Energetic particles: precipitating
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting