Solar Cycle Modulation of Atmospheric Ozone

79-84Solar activity has both long term as well as short term influences on atmospheric ozone. A method has been developed here to distinguish between these influences in the observations of total ozone. Using this method, the relationships between the solar activity as represented by sunspot number and solar 2800 MHz radio flux (F10.7) and the daily variation of total atmospheric ozone during the sunspot minimum (1976) and maximum year (1979) at 5 northern hemisphere stations, have been investigated. These studies reveal that the number of observations attributable to the short term effects are fewer in the sunspot minimum year than in the sunspot maximum year, irrespective of the solar activity index being considered. This has led to the conclusion that solar cycle modulation effects may not be observable in the ozone data. A possible explanation based on the variations in the intensities of short term events between sunspot minimum and maximum years has been given