Seasonal Variations of Wind-Wave Climate in the Indian Ocean Using Satellite Altimeter Data
As per Solomon et al., (2007) estimates for the twentieth century, global mean sea level rise is about 1.7 mm/yr. Apart from global mean sea level rise, the study of wind and wave climate in the oceans forms a major step in understanding the effect of climate change and helps to improve the coastal protection measures and numerical prediction models. The effect of changes in wind and wave climate is quite obvious as it directly affect the livelihood of millions of people living in the coastal areas and the economy of their respective governments.
In the recent years, satellite altimeter data sets have proved to be one of the reliable measurements. The significant wave height and wind speed data for Arabian Sea, Bay of Bengal and Indian Ocean regions were obtained from Topex/Poseidon, Jason-1 and Jason-2 altimeter missions for the period January 1993 to December 2010. The Indian Ocean partitioned into four different regions, in addition to Bay of Bengal and Arabian Sea. Further, a typical year is classified into four seasons in India viz., winter (December-February), summer (March-May), Monsoon (June-September), Post Monsoon (October-November). For each of the region, the yearly variations of sample average and maximum for the different seasons are computed for 18 year period for these two parameters. Since the dynamics of waves in ocean and wind are very complex, attempt has been made to correlate these two parameters. In addition, yearly seasonal percentage of frequencies of occurrences for all regions is analyzed. Further, the probability distribution for four seasons of 18 year period of Arabian Sea and Bay of Bengal are also computed, the details of which are presented and discussed in this paper.
Keywords: Wind, Wave, Altimeter, Seasonal Variation, Indian Ocean
Dinesh kumar Eswaran
Project Associate, Department of Ocean Engineering, Indian Institute of Technology Madras
Prof Sannasiraj Sannasi Annamalaisamy
Professor, Dept of Ocean Engineering, Indian Institute of Technology Madras
Prof Sundar Vallam
Professor, Ocean Engineering, Indian Institute of Technology Madras