Effect of altitude on the variation of pre-monsoon thunderstorm frequency during periods of higher sun spot number

Abstract

The variation of pre-monsoon Thunder Storm Frequency (TSF) depending on the appearance of sun spot (S.S.) have been studied for the period 1955-80 for total 96 stations distributed allover India. For most of the stations we can identify a critical S.S. number in the neighbourhood of mean S.S. 140 above which a clear increasing or decreasing trend of mean TSF is observed with increase of S.S. number. It has also been seen that for almost all the stations having altitude greater than 280m, TSF increases with increase of S.S. number provided it is greater than the critical number.