Simulating the impact of typhoons on air‐sea CO2 fluxes on the northern coastal area of the South China Sea

Abstract

The South China Sea is a typhoon-prone region, and previous studies have shown that typhoons have significant impacts on air-sea CO _2 fluxes. However, the effect of typhoons on the northern coastal area of the South China Sea is not well understood owing to limited observational data. In this study, we used a coupled model to simulate the impact of four typhoons (Hato, Mangkhut, Nida, and Merbok) on the partial pressure of CO _2 in seawater (pCO _2sea ) and the CO _2 fluxes in this area. Our results show that the coupled model effectively reproduces the spatial pattern of pCO _2sea in this region. The response of pCO _2sea to typhoons was determined by typhoon-induced vertical mixing and coastal upwelling, along with initial oceanic conditions. Typhoon Nida caused a decrease in pCO _2sea with Total Alkalinity and Sea Surface Temperature being the primary factors. However, typhoons Hato, Mangkhut, and Merbok caused an increase in pCO _2sea with Dissolved Inorganic Carbon playing a more prominent role. The average CO _2 fluxes during the passage were approximately 6–14 times higher than those before typhoon passage. These results enhance our understanding of the effect of typhoons on air-sea CO _2 fluxes over the northern coastal area of the South China Sea.

Keywords

• typhoons
• pCO2sea
• CO2 fluxes
• South China Sea
• vertical mixing
• coastal upwelling