Abstract

Variations in solar activity on different timescales are a good measure of solar radiation. Solar radiation reaching the earth’s atmosphere impacts on the earth’s climate. Sunspot numbers and F10.7 are widely accepted as good parameters for monitoring solar activity and in this paper. These two solar indices have been employed in determining their effects on Nigerian precipitation on annual and seasonal scales for the period of 102 years covering eleven complete solar cycles that is, from 1902 to 2021. Pearson’s rank correlation and covariance were employed in the study. Results show that there were weak positive and negative correlations between solar activity and rainfall in Nigeria on annual scale and during the rainy season, high amount of dry seasonal rainfall as well as Harmattan rainfall were recorded during low solar activity and a negative covariance existed between rainfall and solar activity during the dry season and Harmattan period and the wet season rainfall and annual rainfall recorded positive covariance.

Keywords: Dry season, F10.7, Precipitation, Solar activity, Sunspot, Wet season