Classification of marine heatwaves in the South China Sea and their thermodynamic features

This is the authors' abstract. We don't add key points for this paper.

The frequency of marine heatwaves (MHWs) in the South China Sea (SCS) has increased recently. However, the relative roles of thermal and dynamic processes regulating the changes of SCS MHWs remain an open question. This study examines all long-lived MHWs (> 10 days) in the SCS from 1982 to 2021, categorizing them into intensified and attenuated MHWs based on the overall trend of sea surface temperature during an MHW event. A mixed-layer heat budget analysis reveals that the thermal processes primarily driven by the latent heat flux are crucial in modulating the SCS MHWs, particularly for attenuated MHWs. However, under intensified conditions, the proportions of dynamically dominated MHWs (40%) is approximately comparable to that of thermally dominated ones (47%). This study highlights the significance of dynamic processes in shaping SCS MHWs and discusses the potential impacts induced by tropical cyclones on these MHWs.