Intercomparison of Atmospheric GCM Simulated Anomalies Associated with the 1997/98 El Niño

Abstract

The atmospheric anomalies for the 1997/98 El Nin o-Southern Oscillation (ENSO) period have been analyzed and intercompared using the data simulated by the atmospheric general circulation models (GCMs) of 11 groups participating in the Monsoon GCM Intercomparison Project initiated by the Climate Variability and Prediction Program (CLIVAR)/Asian-Australian Monsoon Panel. Each participating GCM group performed a set of 10 ensemble simulations for 1 September 1996-31 August 1998 using the same sea surface temperature (SST) conditions but with different initial conditions. The present study presents an overview of the intercomparison project and the results of an intercomparison of the global atmospheric anomalies during the 1997/98 El Nin o period. Particularly, the focus is on the tropical precipitation anomalies over the monsoon-ENSO region and the upper-tropospheric circulation anomalies in the Pacific-North American (PNA) region.