ON THE RELATIONSHIP BETWEEN EURASIAN SNOW COVER AND THE ASIAN SUMMER MONSOON

Abstract

ABSTRACT In this paper, we document the possible linkage between Eurasian snow cover and the Asian summer monsoon by analysing the National Oceanic and Atmospheric Administmtion snow data and the atmospheric circulation fields from the National Meteorological Center analyses. Using updated data, we confirm the inverse relationship between the Eurasian snow cover and Indian monsoon rainfall reported in previous studies. We find that the relationship becomes stronger in the partial correlation calculations excluding the El Niiio years. It is found by comparing years of more snow cover with years of less snow cover that the atmosphere is colder over land and warmer over the oceans during the winter seasons with more snow. During the summer following the winter with more snow cover, the lower atmosphere is colder over the Asian continent, especially north of India. Associated with these temperature changes, a weaker Asian monsoon circulation appears. KEY WORDS: Eurasian snow cover; Asian monsoon; atmospheric circulation; interannual variability