Spatial distribution features extraction of SST in Xiamen Bay and adjacent waters based on remote sensing technology

To further understand the spatial distribution and change patterns of sea surface temperature (SST) in coastal waters. This paper takes Xiamen Bay and adjacent waters as an example and uses multiple HJ-1B SST and MODIS SST as well as other data to preliminarily summarize and analyze the spatial distribution characteristics of SST in winter and summer in this sea area. The results show that in winter, the SST distribution in Tongan Bay, Xiamen Western Waters, and Jiulong River estuary is relatively uniform, and the multi-year average SST inside Section 1 (S1) is not more than $1^{\circ}\mathrm{C}$ higher than that of the outside waters. However, a large area of cold water often appears on the north coast of Weitou – Dadeng Island. The river runoff into the sea reduces in this season, which directly contributes to the weak influence of Jiulongjiang River diluted water on SST distribution. In summer, the SST in Tongan Bay, northern Xiamen Western Waters, Jiulong River estuary, and the northern coast of Weitou – Dadeng Island increases rapidly, and the multi-year average SST inside S1 is more than $1^{\circ}\mathrm{C}$ higher than that of the outside waters. Moreover, large areas of cold water occur near the northern bay mouth. The SST fronts formed by Jiulongjiang River diluted water are distinctive and can extend into the Taiwan Strait under non-typhoon influences. Heavy precipitation caused by typhoon may lead to significant increases in high-temperature and low-salinity runoff and suspended matter concentrations in the study area, thereby affecting the spatial distribution of SST.