The Potential Use of SARAL ALTIKA Towards Coastal Regions – A Case Study on East Coast of India
Authors: Acharyulu P. S. N., Prasad K. V. S. R., Vignudelli S., & Sharma R.
Journal: Modern Approaches in Oceanography and Petrochemical Sciences
DOI: 10.32474/MAOPS.2018.01.000120
Abstract:
Altimeter data provides a precise measurement of wave parameters especially over open ocean. Now, several attempts were made to retrieve wind and wave information towards coastal regions. SARAL/Altika is a first of its kind to operate at such a high frequency to provide better observation of coastal regions. The present study is especially important for the Indian coasts because most of the in-situ observations are either coastally located or at deep water. But there is no sufficient information on data available at intermediate waters, which is very important to addresses several coastal problems. In this paper, an attempt to observe retrieve and validate SARAL along track wave data at different coastal regions along the east coast of India. SARAL validation is carried out at the point closest to the buoy and at all the points along the track close to the coast. The narrow foot print size enables.com to get valid data as close as three km proximity to the coast. SARAL Significant wave height (SWH) estimates are well correlated with the coastal buoy measurements and improves observation of wave height estimates close to the coast. This helps.com to understand transformation of wave from deep water to shallow water. An important advantage of SARAL is better estimation of low wave heights, which is particularly important for the coastal regions along east coast of India especially during non-monsoon periods particularly during the months of January and February. Another important observation from the study was the orientation of the coast and altimeter flight path will also have an effect on altimeter measurement of wave heights particularly over the coastal regions. The seasonal distribution of mean wave climate data prepared from SARAL Altika with a time span of 3 years (April 2013 to March 2016) with one fourth degree resolution. The distribution of significant wave height over west Bay of Bengal displays a seasonal behavior and the impact of monsoon winds. It also displays a zonal character.
Keywords: Satellite Altimetry, Coastal Zone, Coastal processes, Significant Wave Height, Seasons, Low pressure systems
