Spatial and Temporal Variability of Sea Surface Height of Bay of Bengal Derived from Satellite Altimetry Benny Peter + , Mridula K. R., Sahrum Ses and Kamaludin Mohd Omar Department of Geomatic Engineering, Faculty of Geoinformation and Real Estate, University of Technology Malaysia, Johor 81310 Abstract. The spatial and temporal variability of sea surface height anomaly of Bay of Bengal is derived from satellite altimeter observations for the period of 1993-2008. The data used are the weekly Maps of Sea Level Anomaly with 1/3 x 1/3 longitude and latitude resolution weekly files. Annual average of sea level anomaly field is estimated to understand the long term variability. Empirical Orthogonal Functional analysis has been carried out to derive the spatial structure and temporal amplitude of the variability. The first three modes of EOFs capture 80% of the total variance. The temporal amplitude clearly exhibits the influence of climate modes on the sea level of Bay of Bengal. Keywords: Bay of Bengal, Sea Level anomaly, Variability 1. Introduction Bay of Bengal, the north eastern arm of the Indian Ocean is receiving much attention as it is the fertile ground for generation of severe tropical cyclones. It is a semi-enclosed basin which experiences the monsoon winds and associated seasonal reversing circulation. In the northern part of the Bay, mighty rivers from Indian subcontinent discharges vast amount of fresh waters, this is highly contributing to the water characteristics and stratification. Wyrtki (1971) 1 presents a preliminary information of Bay of Bengal waters. Kumar et al (1993) 2 described the seasonal and inter-annual se surface height variations using TOPEX/POSEIDON altimeter data. The seasonal variation of hydrography and circulation of has been accounted in Varkey et al (1996) 3 . Recent studies 4,5,6 has reported surface circulation and mesoscale features in the Bay of Bengal. The propagation of Kelvin and Rossby waves in the Bay of Bengal is discussed in Benny and Mizuno(2000) 7 . Sadhuram et al. (2006) 8 found that the sea surface height variation of Bay of Bengal is well correlated to with the fluctuation of isothermal layer and cyclone heat potential. Recent advances in satellite altimetry provide very accurate estimation of sea surface height, with high spatial and temporal resolution compared to with the in-situ observations. Satellite altimetry derived sea surface height data have been used to produce surface circulation and meso-scale features like fronts, eddies and the vertical motions. Moreover, the time series of Sea surface height data is available even form end of 1992, and it can be used for decadal scale variability studies. The present study determines the variability of sea surface height anomaly of Bay of Bengal during 1993-2008 using satellite altimetry observations and derives the spatial structures and temporal amplitudes of variability. 2. Data and Methodology The satellite altimeter data used in this study are Maps of Sea Level Anomaly (MSLA) produced by the Collect Localisation Satellites (CLS), France for the period 1993-2008. The Maps of Sea Level Anomaly + Corresponding author. E-mail address: bennyneettumkara@utm.my 2012 2nd International Conference on Environment and BioScience IPCBEE vol.44 (2012) © (2012) IACSIT Press, Singapore DOI: 10.7763/IPCBEE. 2012. V44. 23 110