Simulations of the USA drought of 1988

A global general circulation model has been used to investigate the impact of the observed sea-surface temperature anomalies in the Pacific Ocean in 1988. A primary objective was to evaluate the importance and relevance of these anomalies to the 1988 USA drought. A series of experiments was conducted to this end, involving fixed sea-surface temperature anomalies, seasonally varying anomalies for 1987 and 1988, and seasonally varying anomalies for 1988 alone. In all experiments large-scale droughts were simulated over parts of the USA. The most realistic experiments, where results are presented in some detail, reproduced the overall spatial and temporal rainfall anomalies observed over North America in 1988 in encouraging detail. The rainfall variations over North America were found to be sensitive to initial conditions, indicating the need to conduct multiple experiments so that composites of results can be derived. No attempt was made to initialize the model experiments with conditions appropriate to January 1988, hence considerable potential exists for improving the realism of the simulations presented here.