Recent studies on wind seas and swells in the Indian Ocean

Abstract

Winds and waves measured at a few locations along the west coast of India were analysed to study the wave characteristics in the deep as well as near shore regions during different seasons. The potential generation of swells observed in the Arabian Sea is from SW direction during SW monsoon season and from SW/SSW and NW directions during both pre-monsoon and post-monsoon seasons. The NW swells which occurs during shamal event, shows distinct characteristics such as an increase in wave height, decrease in swell period and a common propagation direction (northwest) for wind seas and swells. Also the swells generated at 40 degrees S, propagate in the north Indian Ocean, and enter in the Bay of Bengal than the Arabian Sea. During fair weather season, we can observe distinct and systematic diurnal variation in wind speed, wave height and wave period, especially, simultaneous increase in wave height and decrease in wave period with increase in local wind speeds due to sea breeze system. Fine resolution winds are necessary to understand the effect of land-sea breeze on wind-sea generation in the coastal regions. We have used atmospheric models such as MM5 and WRF to generate fine resolution winds, and the same will be used in wave models such as WAVEWATCH III to reproduce wave characteristics along the coastal regions.