Kiel 2004 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

EP: Extraterrestrische Physik

EP 3: Teilchen und Wellen

EP 3.2: Fachvortrag

Tuesday, March 9, 2004, 16:05–16:25, C

ENERGETIC PARTICLES IN THE ATMOSPHERE: CONTINUOUS ENERGY LOSS vs. MONTE-CARLO — •Schröter Jörg, Heber Bernd, Wolff Edwina, and Kallenrode May-Britt — University of Osnabrück, Barbarastr. 7, 49069 Osnabrück, Germany

Precipitating solar energetic particles (SEPs) ionize the atmosphere, leading to an increase in NO_x and HO_x and consequently a reduction of ozone. Owing to the rather low particle energies, the interaction between SEPs and the atmosphere normally is treated in terms of continuous loss models. In this talk we present Monte-Carlo simulations of the SEP interaction with the atmosphere and compare them to calculations with continuous energy loss models. The main result is a shift of ionization to lower altitudes in the Monte-Carlo model resulting from the correct treatment of the secondaries. Consequences are twofold: first, the shift leads to a better agreement between electron densities observed by EISCAT and calculated ionization rates in the October 1989 event. And secondly, the shifted ionization altitudes allow for a better agreement between modelled and observed NO_x production and ozone depletion.