High-Frequency Observations of Oceanic Internal Waves from Geostationary Orbit Satellites

The Geostationary Orbiting Satellite(GOS)offers extensive opportunities for the study of oceanic internal waves(IWs)through high-frequency observations.In this study,the spatial and temporal distributions of sunglint from 3 GOSs(Himawari-8,FY-4A,and GK-2A)were calculated,and the observation times of IWs in various seas were also recorded.The GOS can continuously observe IWs at a frequency of 10 min for 2 to 3 h.As demonstrated by the application to IWs in the Andaman Sea,the GOS effectively captures the surface features of IWs,including soliton number,the length and wavelength of the leading wave,and the speed and direction of propagation.Furthermore,the GOS can be used to track the dynamic processes of IWs within a short duration and provide more accurate“instantaneous”phase speeds.In the case of the Indonesian Seas,the average error of the GOS-derived phase speeds is 0.13 m/s compared to the Korteweg–de Vries phase speeds.Additionally,a 7-day observation from FY-4A suggests the possibility of diurnal IWs in the Sulu Sea.The advent of high-temporal-resolution GOS provides an enriched dataset for oceanic IW studies,which will contribute greatly to a more comprehensive understanding of IW mechanisms.