Recent Studies on Wind Seas and Swells in the Indian Ocean: A Review

P. V. Ethamony, R. Rashmi, S.V. Samiksha, V. M. Aboobacker
2013 International Journal of Ocean and Climate Systems  
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 premonsoon and post-monsoon seasons. The NW swells which occurs during shamal event, shows distinct characteristics such as an increase in wave height,
more » ... in wave height, decrease in swell period and a common propagation direction (northwest) for wind seas and swells. Also the swells generated at 40 0 An ocean wave spectrum consists of wind seas generated by local winds and swells of distant storms. The characteristics of these waves are different in different seasons. An attempt has been made to understand the wave characteristics at different regions in the Indian Ocean for all seasons. Swells in the Indian Ocean vary in response to the prevailing wind systems according to the seasons. The sea state along the coastal regions of India is significantly modified by these swells . Identification of potential swell generation areas during various seasons is important to understand the effect of swells along the Indian coast, where they superimpose with wind seas and create complex sea states. In general, along the west coast of India, swells are predominant during SW monsoon (Kumar et al., 2000) . Shamal swells are generated in the northwestern Arabian Sea due to strong NW winds, called shamal winds, occur during post-monsoon and early pre-monsoon seasons (Aboobacker et al., 2011) . They propagate in the Arabian Sea with mean wave period ranging between 6 and 8s. However, during the pre-monsoon season, wind seas play a major role in controlling the wave characteristics (Rao and Baba, 1996) . Moreover, sea breeze is very active during pre-monsoon 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.
doi:10.1260/1759-3131.4.1.63 fatcat:eh5biqx74rhk5cnrhn3mlhi5um