The Effect of Solar Activity on the Variation of Annual Precipitation in Iran

In the present paper using wavelet analysis,fourier analysis and statistical analysis we examine the role of the sunspots on the annual precipitation variation and take indicator stations of 7 precipitation regions of Iran. The results indicate that variation of annual precipitation is closely related to the variation of sunspot numbers. Mean annual precipitation in Iran; have a certain variations corresponding with 5,8,11 and 22 year sunspot cycles. Correlation between sunspot activity and annual precipitation variation is not constant and varies along coastal and inland areas in Iran.Therefore, precipitation variations at northern coastal areas in Iran, positively correlated with sunspot cycles, but this correlation in inland areas is vice versa.Existance of alternative drought and wet years that corresponding with sunspot cycles, indicate that, solar activity plays an important role in influencing the precipitation variation in Iran.