The Impact of Typhoon Hinnamnor (September 2022) on Coastal Upwelling in the Northwestern Part of the Sea of Japan according to Satellite Observations

Abstract—Enhanced wind-driven water upwelling was observed off the northwest coast of the Sea of Japan in the summer of 2022. Calculations of the upwelling index show that the coastal upwelling was induced by offshore Ekman transport. The transfrontal exchange in the upwelling zone was determined by mesoscale eddies and filaments. Analysis of multisatellite and meteorological observation data provided an opportunity to consider the influence of the typhoon Hinnamnor (September 2022) on the coastal upwelling zone in the northwestern part of the Sea of Japan. The influence of the typhoon resulted in the separation of the upwelling core from the coast. The advective transport of cold waters to the deep-water part of the sea was determined by the interaction of upwelling zone waters with the mesoscale anticyclonic meander of the Tsushima Current. After the typhoon passage, a sharp temperature decrease in the upwelling filaments was observed. The wind increase led to the formation of a new upwelling zone in the western shelf of the Tatar Strait. As a consequence, under the influence of the coastal upwelling and typhoon in September 2022, negative anomalies of surface temperature were observed in the northern part of the Sea of Japan.