|
|
 |
|
|
Ann. Geophys., 23, 675-679, 2005
www.ann-geophys.net/23/675/2005/
© European Geosciences Union 2005
Cosmic ray-induced stratospheric aerosols: A possible connection to polar ozone depletions
E. A. Kasatkina and O. I. Shumilov
Institute of North Industrial Ecology Problems, Kola Science Centre RAS, Apatity, Russia
Abstract. The model calculations of altitude distribution of CN (condensation nuclei),
plausible centers of sulfate aerosol formation after the occurrence of GLE,
are presented. Events with relativistic solar protons (i.e. protons with
energies >450MeV) are observed at ground level by neutron monitors and
called ground-level events (GLEs) (Shea and Smart, 2001). Analysis of
experimental data and model calculations permits us to explain some
distinctions observed in ozone total content (OTC) variations during several
GLEs. For example, model simulations show a significant CN concentration
enhancement during the May 1990 GLEs of relatively "moderate" magnitude,
when polar ozone "mini-holes" (OTC depletions up to 20%) have been
observed, while no OTC variations and considerable aerosol enhancements were
seen during more powerful GLEs (4 August 1972, 2 May 1998, 14 July 2000)
(Reagan et al., 1981; Shumilov et al., 1995, 2003). Our results demonstrate
that "moderate" GLEs may increase aerosol content significantly and cause
ozone "mini-hole" creation.
Full Article in PDF (316 KB) |
|
|
