Influences of Solar Activity on the Exchange Intensity Between Stratosphere and Troposphere

Abstract

Recordings of Be7 and O3 in the air from a mountain observatory (3 km altitude, Zugspitze) constitute the basis for a study of the question whether the frequency of intrusions of stratospheric air into the troposphere is influenced by solar events. An influx of stratospheric air passing the measuring station is indicated by a noticeable increase in the concentration of these stratospheric constituents. Since 1973 it has been possible to identify a 40% increase in the frequency of stratospheric intrusions 2 to 3 days after solar flares and sector structure boundary passages. Recent studies aimed at a physical interpretation revealed a close correlation between stratospheric intrusions triggered by solar action and the Forbush effect. Recently, it has become possible to show that the intrusions are also coupled with an increase in the O3 concentration in the stratosphere, mainly in its lower layers.