Eurasian Snow Cover versus Indian Monsoon Rainfall—An Extension of the Hahn-Shukla Results

Abstract

The apparent inverse relationship between Eurasian mean winter snow cover extent and the following warm season Indian monsoon rainfall, described by Hahn and Shukla for the 1967–75 period, is substantiated by the addition of five subsequent years of data if known deficiencies in satellite snow observations are accommodated. In this respect, elimination of a bias due to under-observation of snow cover in the Himalayan region during 1967–74 was crucial for the attainment of statistically significant correlations. Nonsignificant correlations for a shorter period (1971–80) suggest that Eurasian and Himalayan region winter snow cover extent, as well as that of Eurasia less the Himalayan region, are all about equally well related to the subsequent Indian monsoon rainfall. Furthermore, Eurasian and Himalayan snow cover extent derived from satellite observations are found to be highly correlated.