Analysis Of Internal Waves In The Andaman Sea And Its Adjacent Waters Based On Remote Sensing Images

The Andaman Sea is the northeastern marginal seas of the Indian Ocean,surrounded by the Asian Peninsulas of Malaya,the Andaman Islands,the Nicobar Islands and Sumatra.Due to its special submarine topography and the existence of a stable vertical stratification of sea-water,internal waves occur when they are disturbed by the external factors,and it's considered as one of those sea areas with most internal waves observed in the world.In this paper,the spatial and temporal distribution,propagation characteristics and internal wave source are analyzed based on multi-sensor satellite remote sensing images in the Andaman Sea and its adjacent waters.The purpose is to provide a more reliable basis for the internal wave study in Andaman Sea.More than 3000 MODIS,GF-1 Landsat and Sentinel-1 A SAR satellite remote sensing images covering the entire Andaman Sea and it's adjacent waters from 2013 to 2016 were obtained to analyze the spatial and temporal distribution,wave propagation feature and source of internal waves in the Andaman Sea.The statistical result shows that internal waves can be observed by the remote sensing primarily in four areas:north of Sumatra Island,middle of the Andaman Sea,north of the Andaman Sea and west of Nicobar Islands.The internal waves with a relative large spatial scale in northern Sumatra and eastern Andaman Islands are more active in the Andaman Sea.No internal waves in the deep sea and the gradually changing bathymetric gradients areas of the Andaman Sea have been observed based on current limited remote sensing data.The spatial distribution of observed internal waves is similar each year from 2013 to 2016 in the Andaman Sea.Internal waves can be observed in the Andaman Sea all through the year,most in February to April.For the propagation directions distribution,most internal waves in the Andaman Sea propagate to the west towards the Peninsulas of Malaya.In the north sea area,some internal waves propagate eastward or southeastward in north of Sumatra Island and eastern Nicole Islands,southeastward or southwestward in eastern Andaman Island.In addition,we found some internal waves propagate from the Andaman Sea to the Indian Ocean.In addition,the exploration of the source of the Andaman wave has been the focus of attention.In this paper,the sources of the Andaman sea wave are discussed based on the visible light and SAR remote sensing images.The origins of Andaman waves are same as those described by previous researchers.Internal waves occur in the western Andaman Sea,and there is an internal wave reflection zone in the north of Andaman Sea and northern Sumatra.In this paper,two source region of internal wave and a reflection region of internal wave are newly discovered,which are located in the channel between south Nicobar Islands,south Pre-Paris strait and the northern Sumatra.