Tropopause height and solar activity

The variations in tropopause height with sunspot activity for 11 Indian stations have been studied for the period 1960 to 1972. The annual mean tropopause heights were plotted against Zurich sunspot numbers. The plots show clear latitudinal dependence in height variations. We calculated the correlation coefficients between tropopause height and sunspot numbers for lags varying from 0 to 5 years. The correlation coefficients for lag = 0 and lag = 3 exhibit entirely different latitudinal dependence. The largest negative correlation for mid-latitudes and an insignificant correlation for equatorial regions is found with lag = 0; whereas, for a lag of 3 years, the largest negative correlation is seen in the equatorial region with insignificant correlation for mid latitudes. This study shows that in low latitudes both the particle and electromagnetic part of the solar radiation cause changes in atmospheric circulation. Differences in sign of correlation coefficients between Indian and American regions suggest strong longitudinal dependence of solar-meteorological relationships.