The Indian monsoon: 1. Variations in space and time

Abstract

Understanding the nature of the variation in the rainfall that occurs on different spatial scales (from that of a station or a taluk to that of the entire country) and on different time scales (from days to months, to the whole season, to interannual and longer), unraveling the underlying mechanisms and hence predicting the variation is the central problem of monsoon meteorology. In this series of articles, I shall attempt to address the 'how and why' of the Indian monsoon. I begin with a brief discussion of what we know about the nature of the observed variability of the rainfall on different regional and time-scales. What we understand about the physics of the monsoon and its variability will be considered in the next part. Finally I consider why we are not able to predict it better than we do and the challenges to be met for substantive improvement in understanding and prediction of the monsoon.