Atmospheric ionization module osnabrück (AIMOS): 2. Total particle inventory in the October-November 2003 event and ozone

Abstract

Precipitating solar protons contribute to ozone depletion in the atmosphere; α particles and electrons also precipitate during solar energetic particle (SEP) events. If the SEP is accompanied by a shock, then magnetospheric particles can also be injected into the atmosphere as the shock hits the magnetosphere. Both particle species in both particle populations show distinct energy spectra (and thus penetration depth in the atmosphere) and precipitate in different regions: the SEP inside the polar cap and the magnetospheric particles inside the auroral oval. In this paper, we reevaluate the 3-D spatial and temporal precipitation patterns of these particle populations for the October-November 2003 event and compare the results to conventional approaches using only protons in evaluating SEP consequences. The main results are as follows: (1) The 3-D model AIMOS gives a very differentiated picture of the global ionization maps; (2) if only protons are considered, the differences between the 3-D model and the conventional approach of homogeneous precipitation inside the polar cap are small in NOx production and ozone depletion in the mesosphere and stratosphere; and (3) the consideration of electrons in addition to protons leads to significant increases in atmospheric ionization in the mesosphere, less so in the stratosphere. This is reflected in changes in the chemical composition as shown here for ozone depletion and an increase of NOx. Copyright 2010 by the American Geophysical Union.