Abstract: The distribution characteristics of marine heat waves in the northwest Pacific Ocean, from July 1 to September 30, 2022, is analyzed basing on the Coral Reef Watch (CRW) heat waves monitoring dataset using satellite remote sensing. The typical marine heat waves processes and formation mechanism at single stations in three regions with strong heat waves were mainly explored. A composite analysis of atmospheric and ocean variables was used to investigate the mechanism of marine heat waves. The results indicate that: (1) The spatial distribution of various attributes of marine heat waves in the northwest Pacific has certain similarities except for the maximum intensity, and overall, the high values are relatively concentrated. (2) The properties of marine heat waves in the offshore area of Jiangsu are significantly higher than those in other regions; the Kuroshio basin near Taiwan has a lower maximum intensity but longer duration of marine heat waves; the values of various attributes of marine heat waves in the offshore area of Guangdong are above the spatial mean of Northwest Pacific Ocean. (3) The generation of a marine heat wave in the offshore area of Jiangsu within 92 days is closely related to the combined effect of atmospheric forcing under the expansion of the Western Pacific Subtropical High and the advection transport process of a large amount of sensible heat and latent heat in the Kuroshio basin. The marine heat wave in the Kuroshio basin near Taiwan and the offshore area of Guangdong is mainly caused by the increased solar radiation under the control of the Western Pacific Subtropical High.

Key words: marine heatwaves, Northwest Pacific, atmospheric forcing, sea surface temperature