Internal Solitary Waves in the Central Andaman Sea Observed by Combining Mooring Data and Satellite Remote Sensing

Abstract

The behavioral characteristics of internal solitary waves (ISWs) in the central Andaman Sea were revealed by analyzing multisource satellite remote sensing images combined with synchronous mooring data. The relationship between the generation time and tides of ISWs in the central Andaman Sea was analyzed and discussed. The ISWs in the central Andaman Sea exhibit a notable semidiurnal tidal cycle, primarily occurring during the spring tide. Additionally, it was observed that larger currents can generate ISWs with larger amplitudes. The propagation velocity of the ISWs initially increases and then decreases from the source, with no significant overall change in the deep areas. Based on the analysis of satellite remote sensing images that cover the source of ISWs in the central Andaman Sea, the generation time of ISWs was estimated. A comparison was made between the estimated generation time and the tidal flow predicted from the TPXO 9 global tidal model at the location of the ISW source. It was found that ISWs are generated when the westward tidal flow reaches its maximum. The ISWs in the central Andaman Sea are generated between the islands of Car Nicobar and Teresa Island. They propagate eastward into the Andaman Sea, grow in amplitude, split into multiple waves, dissipate, and vanish in the waters near the Danao Islands. The entire life cycle of these waves lasts for approximately 3∼4 days.