Ionization effect of solar particle GLE events in low and\ middle atmosphere 1Sodankylä Geophysical Observatory (Oulu unit), University of Oulu, Finland
03 Mar 2011
2Ioffe Physical-Technical Institute, St. Petersburg, Russia
3Institute of Physics, St.Petersburg State University, St. Petersburg, Russia
4Space Science Division, Naval Research Laboratory, Washington, DC, USA
5Praxis, Inc., Alexandria, VA, USA
Received: 04 October 2010 – Published in Atmos. Chem. Phys. Discuss.: 14 December 2010 Abstract. Using a new reconstruction of the solar proton energy spectra for Ground Level Enhancement (GLE) events,
based on fits to measurements from ground-based and satellite-borne instruments covering a wide energy range,
we quantitatively evaluate the possible ionization effects in the low and middle atmosphere
for 58 out of the 66 GLE events recorded by the world-wide neutron monitor network since 1956.
The ionization computations are based on the numerical 3D CRAC:CRII model.
A table of the ionization effect caused by the GLE events at different atmospheric heights
is provided. It is shown that the direct ionization effect is negligible or even negative, due to the
accompanying Forbush decreases, in all low- and mid-latitude regions.
The ionization effect is important only in the polar atmosphere, where it can be dramatic in the
middle and upper atmosphere (above 30 km) during major GLE events.
Revised: 17 February 2011 – Accepted: 18 February 2011 – Published: 03 March 2011
Citation: Usoskin, I. G., Kovaltsov, G. A., Mironova, I. A., Tylka, A. J., and Dietrich, W. F.: Ionization effect of solar particle GLE events in low and\ middle atmosphere, Atmos. Chem. Phys., 11, 1979-1988, doi:10.5194/acp-11-1979-2011, 2011.