Effects of barotropic tides and ocean stratification on the generation and propagation of internal solitary waves in the deep south Andaman Sea

• Published in: Dynamics of atmospheres and oceans 2022-12, Vol.100, p.101329, Article 101329
• Main Authors: Huang, Songsong, Wang, Jing, Lu, Kexiao, Cui, Haiji
• Format: Article
• Language: English
• Subjects: Andaman Sea; Internal solitary wave; MITgcm; Numerical simulation
• ISSN: 0377-0265; 1872-6879
• DOI: 10.1016/j.dynatmoce.2022.101329

The Andaman Sea is one of the sea areas with the most internal solitary waves (ISWs) observed in the world and an ideal experimental site for studying the generation and propagation characteristics of ISWs. In this paper the generation and propagation characteristics of the ISWs in the deep south Andaman Sea are investigated based on the results of Massachusetts Institute of Technology General Circulation Model (MITgcm) numerical models. The reliability of the model is verified. The sea surface current gradient of 3D model is consistent with Terra MODIS and Sentinel-1A SAR remote sensing images. The turbulent kinetic energy dissipation rate of 2D model is also consistent with in-situ mooring measurements in other sea areas. The variation of temperature, energy and current field caused by barotropic tides and oceanic stratification are analyzed and compared. The results show that ISWs cannot be generated directly by the individual diurnal tides in our 2D model, and ISWs are mainly generated by the semidiurnal tides in the deep south Andaman Sea. Ocean stratification affects the waveform, the velocity and the generation position of ISWs. ISWs are easier to form in the hot season because of a larger Ursell number and stronger nonlinearity. •To study the generation and propagation of ISWs in the south Andaman Sea, 2D and 3D MITgcm models are investigated.•Internal solitary waves are generated by the semidiurnal tide in the deep south Andaman Sea.•Seasonal ocean stratification affects the waveform, the velocity and the generation position of internal solitary waves.•ISWs are easier to form in the hot season because of a larger Ursell number and stronger nonlinearity.