On the distinction of seasonal internal solitary waves characteristics in the Lombok Strait based on multi satellite data

This study presents a multi-satellite approach utilizing synthetic aperture radar (SAR) and optical sensors to distinguish the characteristics of internal solitary waves (ISWs) during different seasons in the Lombok Strait. SAR and optical sensors are employed to estimate the dynamic parameters (soliton number, wavelength, and phase speed) of ISWs during different seasons based on the detected ISW patterns. ISW characteristics in the Lombok Strait during two seasons were observed using Sentinel-1/SAR, GCOM-C/SGLI, and Terra/MODIS sensors. Results indicated that Sentinel-1/SAR detected a higher soliton number for the northward-propagating ISWs in the Lombok Strait during the north-west monsoon (NWM) than the south-east monsoon (SEM) period. The identified wavelengths of ISWs were wider during the SEM than during the NWM whenever two packets were detected in one image. Similar variations were observed by optical sensors (SGLI and MODIS). Estimation of ISW phase speed derived from multi-satellite images and the Korteweg-de Vries (KdV) equation showed that the phase speed was faster during the NWM than the SEM. These results correlated with the seasonal variation of thermocline depth and density differences between the two layers. Because of the bias caused by turbid water, a pattern of high chlorophyll-a was observed during the NWM period in the SGLI, MODIS, and VIIRS products. Propagation of turbid water to the north was assumed to be a result of the intense ISW activity in this area. Highly variable currents due to ISW activity in the Lombok Strait area were assumed to cause the anomalous sediment transport in this study. The multi-satellite observation data used in this study enhanced understanding of the influence of ISWs on coastal interactions in the Lombok Strait.