Study of Internal Solitary Waves Characteristics Using Synthetic Aperture Radar Imagery and the Korteweg-de Vries Numerical Model in the South Andaman Sea Alfiza N., Lumbangaol M. G., Putri K.M.A., Mahendra S.A.H., Zhafran M.L. and Helmi M.
Departement of Oceanography, Faculty of Fisheries and Marine Science, Universitas Diponegoro, Indonesia
Departement of Marine Science, Faculty of Fisheries and Marine Science, Universitas Diponegoro, Indonesia
Abstract
Internal solitary waves (ISWs) are energetic nonlinear phenomena that strongly influence ocean mixing and circulation. internal solitary waves (ISWs) generated are by the transformation of internal tides as they interact with complex seafloor topography, leading to intense vertical mixing and influencing subsurface transport processes. This study examines ISWs in the Southern Andaman Sea through the integration of Sentinel-1 Synthetic Aperture Radar (SAR) imagery and the Korteweg-de Vries (KdV) numerical model. SAR analysis on 31 January 2018 identified six soliton packets with alternating bright-dark band patterns, propagating east-southeast from the 500-1000 m bathymetric contours. Surface signatures revealed stronger backscatter in the leading soliton and gradual attenuation downstream. Numerical simulations based on hydrographic data confirmed substantial isopycnal displacement and high energy concentration in the leading soliton, with amplitudes up to ~138 m, stable phase speed of ~2.9 m/s, and kinetic energy dominance (KE/APE ratio > 14). Both approaches consistently indicated energy dissipation, manifested in reduced amplitude, velocity, and soliton strength during propagation. By combining SAR observations with KdV modelling, this study provides spatial and quantitative insights into ISW dynamics. The results establish the Southern Andaman Sea as a hotspot for large ISWs and underline implications for navigation safety, fisheries, and offshore structures.
