On the relationship between Tibetan snow cover, the Tibetan plateau monsoon and the Indian summer monsoon



[1] More than a century ago, Blanford suggested that an inverse relationship existed between summer rainfall over Northwest India and snow cover in the western Himalaya. Recently it has been found that there is a positive correlation between Tibetan snow cover and Indian summer monsoon rainfall (IMR), a result opposite to that of Blanford. In this paper, we attempt to reconcile these contradictory observations through the analysis of spatial and temporal variability of Tibetan snow cover and its relationship with the Indian summer monsoon. We show that there exists an east-west dipole-like correlation pattern between snow cover over the Tibetan plateau and IMR that underwent a change in sign around 1985. We argue that variability in the Tibetan plateau monsoon is responsible for the spatial and temporal variability in the relationship between Tibetan snow cover and the Indian summer monsoon.