CASE STUDIES OF STRATOSPHERIC INTRUSIONS ASSOCIATED WITH INCREASED RADIOACTIVITY IN THE SURFACE AIR

N. P. Shakina, I. N. Kuznetsova, and A. R. Ivanova

Cases of sharp increase in total beta-activity concentrations in the surface air in Russia in 1996—1998, with background values exceeded 5 to 10 times, are analyzed. High Be-7 concentrations in the samples confirm that the radioactivity peaks are caused by deep stratospheric intrusions. Characteristic features of atmospheric flow evolution during these episodes and particularities of tropopause topography, jet stream, and frontal parameter fields associated with the stratospheric intrusions are revealed and described.