Indian summer monsoon precipitation extremes and their relation with global sea surface temperatures

Sea surface temperatures are significantly linked with Indian summer monsoon (JJAS) precipitation anomalies through different ways of teleconnections. However, the extremes of summer monsoon rainfall and their remote relation with global SSTs are not explored. Therefore, an attempt is made in this study to explore the teleconnective relation of global SSTs with the various indices of precipitation extremes in terms of their frequency, duration and depth. For the computation of indices of precipitation extremes, we used daily precipitation data from 53 stations distributed all over India for 30 year period (1984-2013). Strong significant negative relationship exists between equatorial pacific sea surface temperatures and indices of precipitation extremes. Interestingly correlations with the indices of frequencies defined as seasonal count of days when rainfall exceeds 30, 20, and 10 mm show that strength and spatial extent of negative correlations over equatorial pacific region decreases with increase in threshold values (See Figure below).