Modeling the Indian Ocean

Accurately representing physical processes over the Indian Ocean in global climate models is critical for predicting weather and climate in many regions over the globe. Because of the development of high-resolution ocean general circulation models (OGCMs) in recent years, the mean and seasonal cycle of upper ocean circulations, including narrow boundary currents, are reproduced reasonably well by global OGCMs integrated with given surface forcing fields. Yet quantitative comparisons of detailed upper ocean structure and currents, especially over the southern Indian Ocean, are still difficult because of a sparse coverage of in situ observations. Simulations and prediction of Indian Ocean climate variability such as the Indian Ocean dipole have been improved using high-resolution ocean-atmosphere coupled models. Regional coupled climate models are shown to be useful for identifying important local air-sea interaction processes. Coupled ecosystem models have been developed and used recently for investigating biogeochemical processes such as the dynamics of oxygen minimum zones.