A study on the effect of Eurasian snow on the summer monsoon circulation and rainfall using a spectral GCM

摘要

Many studies based on observed data indicate the inverse relationship between the Eurasian snow cover/depth and the Indian summer monsoon rainfall (ISMR). The purpose of this study is to confirm the inverse snow-ISMR relationship by using the observed snow depth data as boundary conditions in the spectral general circulation model (GCM) of Indian Institute of Technology, Delhi (IITD), and to examine the influence of Eurasian snow depth on the monsoon circulation. The original model belonging to the European Centre for Medium range Weather Forecasts (ECMWF) at resolution T21 has been modified extensively to a higher resolution of T80L18 at IITD. A two-dimensional Lanczos digital filter has been used to represent the orography realistically.