Increased frequency of stratospheric injections into the tropopause as triggered by solar events

Abstract

For some years concentrations of cosmogeneous radionuclides (Be7, P32, P33, S35) in the air have been continuously measured at a high mountain station (3 km a.s.1.). Simultaneously-occurring peaks of these concentrations indicate an injection of stratospheric air through the tropopause into the troposphere. Location of injection and trajectories of stratospheric air masses are determined. The frequency of injections increases significantly, by about 50%, after H α -flares near the central meridian of the Sun. An increase also occurs after passages of the interplanetary magnetic field sector boundaries. The causal sequence of stratospheric air injections triggered by solar events is being investigated. These phenomena influence the residence time of impurities in the stratosphere as a function of solar activity and injections of stratospheric air, which may be highly polluted by radioactivity, into the biosphere.