NEW RESULTS REGARDING THE INFLUENCE OF SOLAR-ACTIVITY ON THE STRATOSPHERIC-TROPOSPHERIC EXCHANGE

The dependence of stratospheric intrusions on solar events is analyzed on the basis of 8-years' recordings of the concentration of stratospheric radionuclides and the ozone at 3 km altitude, as well as of the atmospheric profile of the ozone concentration and the total ozone. A significant, even though weak influence of solar magnetic sector structure boundary passages of type-/+ can be identified, a seasonal influence, however, is also observed. The strong 50 to 80% increase in the frequency of stratospheric intrusions after solar Hα-flares is significant and completely independent of the phase of the solar cycle and season. The total atmospheric ozone shows also a correlation with solar flares: A well defined maximum on the day preceding the flare. The neutron density clearly shows the Forbush decrease on the Hα-key day. Using key days with Forbush minimum for the superposed epoch analysis reveals a significant maximum of the Be 7-concentration on the day before the flare (rise by about 45 to 60%). Notable is the following sequence: Approximately 3 days before the solar flare the neutron density begins to decrease, 1 to 2 days before the flare the total atmospheric ozone maximizes, and 2 to 3 days after the flare one finds the maximum of the Be 7 in the troposphere as a consequence of the stratospheric intrusion. Around days with maximum Be 7-concentration the reliability of weather forecasts is clearly reduced - a fact, which at this point is obviously indicative of an acute activation of a labile atmospheric condition. We selected some characteristic individual cases to demonstrate by means of tables the time lapse of typical solar atmospheric and geophysical variables associated with solar flares. The attendant structures of the vertical ozone profile are discussed. Some preliminary reflections on a physical link are set forth. © 1979 Springer-Verlag.