Spatiotemporal Variability of Seasonality of Rainfall Over India

Abstract

AbstractWe analyzed 113 years (1901–2013) of daily rainfall over India to investigate spatiotemporal variability of rainfall seasonality. Rainfall seasonality and mean annual rainfall were found to be high over the Western Ghats, central, and northeastern parts of India and over the Indo‐Gangetic plains, and low over northwest, southern, and northernmost parts of India. Significant decreasing trends in seasonality coupled with decreasing rainfall were found over parts of central India, the Indo‐Gangetic plains, and parts of Western Ghats. Trends in timing of peak rainfall indicate later occurrence in the season, especially over southern Indo‐Gangetic plains, by ~10–20 days per century. In addition, there is a general decrease in the wet‐season duration throughout India by ~10–20 days per century. El Niño–Southern Oscillation and Indian Ocean sea surface temperatures were found to strongly influence seasonality and rainfall over large parts of India. The changes to rainfall and its seasonality will have profound socioeconomic implications for India.