Berlin 2005 – wissenschaftliches Programm
EP 2.12: Vortrag
Freitag, 4. März 2005, 17:45–18:00, TU BH349
Model Simulations of Thermospheric NO Intrusions and Comparison with MIPAS-ENVISAT observations — •Thomas Reddmann1, Bernd Funke2, Thomas von Clarmann1, Sven Gabriel1, Wolfgang Kouker1, Manuel Lopez-Puertas2, Roland Ruhnke1, Gabriele Stiller1, and Roland Uhl1 — 1Inst. of Meteorology and Climate Research, Research Center and University of Karlsruhe — 2Instituto de Astrofisica de Andalucia, Granada
The contribution of NO intrusions from the lower thermosphere into the middle atmosphere to the total NOy budget during periods of higher solar activity and their effect on ozone chemistry is still an open question. During its first two years of operations the MIPAS instrument on the ENVISAT satellite observed NO enhancements in polar winter. In addition, first results of the solar storm period in October/November 2003 also showed enhanced NO concentrations in the upper stratosphere and ozone loss subsequent to this event. The MIPAS observations therefore provide a data set through which models of the middle atmosphere can be validated in respect of downward transport inside the polar vortex and the effect on ozone chemistry can be estimated.
Here we focus on first results of a comparison of the MIPAS observations of NO, ozone and stratospheric tracers with results obtained with the middle atmosphere model KASIMA. We discuss aspects of model initialization as data assimilation and the parameterization of photolysis rates especially for NO at high solar zenith angles.