1. Solar activity and extreme rainfall over Kerala, India
- Author
-
Thomas, Elizabeth, Vineeth, S., and Abraham, Noble P.
- Subjects
Physics - Atmospheric and Oceanic Physics ,Physics - Space Physics - Abstract
In this paper, we examine the relationship between solar activity and extreme rainfall events in Kerala, India. Kerala receives minimum and maximum rainfall during the winter and monsoon seasons, respectively. Sunspot number, F10.7 Index, and cosmic ray intensity are the solar indices considered and their variations with rainfall were studied over a period of 57 years (1965-2021), i.e., starting from Solar Cycle 20. For each solar cycle, correlative studies are performed and correlation coefficients are calculated. We find that rainfall in Kerala is correlated with sunspot activity, but with varying degrees of significance. During Solar Cycle 21, rainfall and solar activity are correlated with high significance during both winter and monsoon seasons. The variation of different solar indices with rainfall is studied. The winter season showed a better link between the sun and rainfall than the monsoon season. The years with rainfall surplus and deficiency are calculated and compared with the solar indices. We find that the years with rainfall excess and deficit mostly occur in the years around solar maximum or minimum (within $\pm$2 years). We hypothesise a physical relationship between solar activity and extreme rainfall events in Kerala that contributes to their predictability., Comment: 17 pages, 10 figures; (Earlier version available at https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4596139)
- Published
- 2024