Trends of maximum annual sea surface temperature in the Eastern China Seas

The increasing ocean warming due to climate change significantly threatens regional marine ecosystems by raising the frequency and severity of extreme temperature events. This study examines patterns and trends of maximum annual sea surface temperature (T max ) in the Eastern China Seas from 1985 to 2022. The results show a significant warming trend in T max , exceeding the global average, with notable differences between southern and northern regions. The northern T max warming rate is faster, with occurrence times significantly advancing, while the southern T max warming rate is slower, with occurrence times significantly delayed. The southern T max and its timing are closely correlated with the annual maximum air temperature and its timing. In the north, T max timing is influenced by latent heat flux (Q LH ); a significant increase in August Q LH inhibits the continued rise of SST, causing T max to advance. The study also highlights a significant increase in marine heatwaves at T max timing, with higher T max indicating a higher occurrence probability. By elucidating these T max trends and dynamics, our study enhances understanding of regional climate impacts, supporting targeted conservation efforts and adaptive ecosystem management strategies in the Eastern China Seas.