Fundamental challenge in simulation and prediction of summer monsoon rainfall
Article first published online: 12 AUG 2005
Copyright 2005 by the American Geophysical Union.
Geophysical Research Letters
Volume 32, Issue 15, August 2005
How to Cite
2005), Fundamental challenge in simulation and prediction of summer monsoon rainfall, Geophys. Res. Lett., 32, L15711, doi:10.1029/2005GL022734., , , , , , and (
- Issue published online: 12 AUG 2005
- Article first published online: 12 AUG 2005
- Manuscript Accepted: 13 JUL 2005
- Manuscript Revised: 17 JUN 2005
- Manuscript Received: 16 FEB 2005
 The scientific basis for two-tier climate prediction lies in the predictability determined by the ocean and land surface conditions. Here we show that the state-of-the-art atmospheric general circulation models (AGCMs), when forced by observed sea surface temperature (SST), are unable to simulate properly Asian-Pacific summer monsoon rainfall. All models yield positive SST-rainfall correlations in the summer monsoon that are at odds with observations. The observed lag correlations between SST and rainfall suggest that treating monsoon as a slave possibly results in the models' failure. We demonstrate that an AGCM, coupled with an ocean model, simulates realistic SST-rainfall relationships; however, the same AGCM fails when forced by the same SSTs that are generated in its coupled run, suggesting that the coupled ocean-atmosphere processes are crucial in the monsoon regions where atmospheric feedback on SST is critical. The present finding calls for reshaping of current strategies for monsoon seasonal prediction. The notion that climate can be modeled and predicted by prescribing the lower boundary conditions is inadequate for validating models and predicting summer monsoon rainfall.