HR: 17:00h
AN: SA34A-05 INVITED    [Abstracts]
TI: Energetic Particle Precipitation Effects on the Polar Winter Stratosphere as Observed by MIPAS/Envisat
AU: * Funke, B
EM: bernd@iaa.es
AF: Instituto de Astrofisica de Andalucia, CSIC, Camino Bajo de Huetor, 50 Apdo. 3004, Granada, E-18008, Spain
AU: Lopez-Puertas, M
EM: puertas@iaa.es
AF: Instituto de Astrofisica de Andalucia, CSIC, Camino Bajo de Huetor, 50 Apdo. 3004, Granada, E-18008, Spain
AU: Stiller, G
EM: gabriele.stiller@imk.fzk.de
AF: Institut fur Meteorologie und Klimaforschung, Forschungszentrum Karlsruhe, Postfach 3640, Karlsruhe, D-76021, Germany
AU: von Clarmann, T
EM: thomas.clarmann@imk.fzk.de
AF: Institut fur Meteorologie und Klimaforschung, Forschungszentrum Karlsruhe, Postfach 3640, Karlsruhe, D-76021, Germany
AU: Reddmann, T
EM: thomas.reddmann@imk.fzk.de
AF: Institut fur Meteorologie und Klimaforschung, Forschungszentrum Karlsruhe, Postfach 3640, Karlsruhe, D-76021, Germany
AU: Sinnhuber, M
EM: miriam@iup.physik.uni-bremen.de
AF: Institut fur Umweltphysik, University Bremen, Postfach 330440, Bremen, D-28334, Germany
AB: Energetic particle precipitation (EPP) in the polar atmosphere has important implications on stratospheric ozone chemistry. Solar protons or highly energetic electrons generated during solar storms cause sporadicly in situ production of stratospheric NO_x and HO_x radicals involved in catalytic ozone destruction. Further, NO produced continuously in the mesosphere and lower thermosphere by medium energy electron precipitation descends to the stratosphere during the polar winter, where it represents an additional, though variable source of NO_x. The capability of MIPAS to measure all important NO_y species, as well as ClO and HOCl with global coverage including the polar night regions make this instrument an ideal candidate to study EPP effects on stratospheric chemistry. We present a quantitative assessment of EPP-induced stratospheric composition changes as observed by MIPAS during 2002-2004, including the unusually strong solar proton event in October/November 2003. Enhanced levels of NO_x in the upper stratosphere and lower mesosphere have been found for several winters within polar vortices. NO_x was subsequently transformed to other NO_y species, leading, for example, to a secondary upper stratospheric HNO₃ maximum. The impact of upper stratospheric enhanced NO_x levels, the mechanisms of their transformation to other NO_y species, and their effect on the stratospheric ozone budget has been studied with chemical models. The stratospheric ozone loss in the polar regions reached 20 DU and lasted over months to years.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 3300 ATMOSPHERIC PROCESSES
DE: 7514 Energetic particles (2114)
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting