Simulations of the Indian summer monsoon with a coupled ocean-atmosphere model on PARAM Padma

Simulations with climate models is a computationally challenging problem. It is even more challenging when a coupled model of ocean and atmosphere is used. In this article, we report the implementation of a coupled ocean-atmospheric model on the PARAM Padma, a high-performance computer developed by Centre for Development of Advanced Computing, Bangalore and results from a 100-year simulation with this model. This is perhaps one of the largest computational experiments in the field of climate modelling conducted in the country. The computation took about 27 days of computer time on 104 processors spread over a period of three months. We find that the simulations of the Indian summer monsoon with the coupled model are more realistic than with the atmospheric component alone. We also find that the simulation of ocean state is reasonable, although the simulated sea surface temperature is colder than the observed climatology.