Application of principal component analysis to understand variability of rainfall

Abstract

The usefulness of principal component analysis for understanding the temporal variability of monsoon rainfall is studied. Monthly rainfall data of Karnataka; spread on 50 stations for a period of 8 years have been analysed for interseasonal; interannual variabilities. A subset of the above data comprising 0 stations from the coherent west zone of Karnataka has also been investigated to bring out statistically significant interannual signals in the southwest monsoon rainfall. Conditional probabilities are proposed for a few above normal/below normal transitions. A sample prediction exercise for June-July using such a transition probability has been found to be successful.