The Abnormal Indian Summer Monsoon of 2000

Abstract

Diagnostic analysis of observations and a series of ensemble simulations using an atmospheric general circulation model (GCM) have been carried out with a view to understanding the processes responsible for the widespread suppression of the seasonal summer monsoon rainfall over the Indian subcontinent in 2000. During this period, the equatorial and southern tropical Indian Ocean (EQSIO) was characterized by persistent warmer than normal sea surface temperature (SST), increased atmospheric moisture convergence, and enhanced precipitation. These abnormal conditions not only offered an ideal prototype of the regional convective anomalies over the subcontinent and Indian Ocean, but also provided a basis for investigating the causes for the intensification and maintenance of the seasonal anomaly patterns.