Computation of large scale currents in the Arabian Sea during winter using a semi-diagnostic model

A 3-dimensional, semi-diagnostic model with 331 levels in the vertical has been used for the computation of climatic circulation in the western tropical Indian Ocean. Model is driven with the seasonal mean data on wind stress, temperature and salinity data. Results of numerical experiments for winter season at selected levels are analysed and presented in this paper. The broad features of circulation during winter season such as the westward NEC and SEC, eastward ECC and southward Somali Current is computed successfully by the model. The SEC, NMC and MZC can be seen in all the levels 20, 50, 150 and 300 m depths. Model results show a southward undercurrent at 50 m depth along west coast of India, a southward subsurface current off Somali near 5 degree N at 150 and 300 m depths. Computed circulation features at the surface and subsequent levels showed fairly good agreement with the observations.