Analyzing Sea Temperature Variation in Response to Typhoon Lekima (1909)

Multiple-source satellite data, high-frequency data directly measured using marine meteorological drift buoy, Argo floats data, and Analysis Dataset were used in this study to analyze the temporal and spatial variation in sea surface temperature (SST) and vertical seawater temperature profile during supertyphoon Lekima (1909). The results showed that the maximum SST decrease could reach above 5°C after “Lekima”. The cooling area was more concentrated on the right side of the typhoon’s track. “Lekima” resulted in the vertical mixing of the near-surface water and subsurface water column, and the subsurface water column was heated, increasing the depth of the mixed layer and deep-water temperature. According to the abovementioned data, the emergence of the main SST decreased region was 1 or 2 days later than the appearance of the “Lekima” center area. Among all the data, the marine drift buoy data could more accurately describe the SST variation and could be used as a reference to verify the satellite data because the drifting buoy could directly measure the SST at high frequencies. Moreover, the cooling effect in different marine regions also depended on the marine environment. The cooling effect was concentrated in the mixed layer when “Lekima” got closer to Kuroshio. Conversely, when “Lekima” was far from Kuroshio, the cooling effect could extend to the thermocline.