An Apparent Relationship between Eurasian Spring Snow Cover and the Advance Period of the Indian Summer Monsoon

Abstract

Satellite images and Northern Hemisphere snow cover charts have been used to derive the Eurasian spring (March-May) snow cover area for the period 1967?78. The advance period of summer monsoon from the extreme southern tip of peninsular India to northwest India was derived from the Indian Daily Weather Reports. Year-to-year variations of the advance period of the Indian summer monsoon were compared with the Eurasian spring snow cover area and also with the Eurasian snowmelt, from March to May. This preliminary study revealed that springs with extensive snow cover area over Eurasia were followed by a longer advance period of the Indian summer monsoon. Further, an inverse relationship (negative correlation) is found between spring snowmelt and the advance period, that is, springs with more snowmelt over Eurasia were related with a shorter advance period of the Indian summer monsoon.