Impact of Air-Sea Turbulent Heat Flux on Eddy-Induced Sea Surface Temperature in the Northwestern Pacific Ocean.

Mesoscale eddies play an important role in upper-ocean heat redistribution, yet the mechanisms controlling eddy-induced sea surface temperature anomaly (SSTA) patterns remain incompletely understood. In this study, we investigate how air-sea turbulent heat flux damping modulates eddy-induced SSTA patterns in the Subtropical Countercurrent (STCC) and Kuroshio Extension (KE) regions of the northwestern Pacific. Using satellite observations, reanalysis products, and eddy trajectory data from 2010 to 2019, we composite cyclonic and anticyclonic eddies in different seasons and quantify the relative contributions of monopole and dipole SSTA components. The results show that the STCC region exhibits a larger dipole contribution and a higher normalized SSTA damping rate than the KE region in both warm and cold seasons. This regional contrast suggests that stronger SSTA damping is associated with a more pronounced dipole SSTA pattern, whereas weaker damping favors a more monopole structure. The spatial distribution of the normalized damping rate closely resembles that of the turbulent heat flux response rate, while mixed-layer depth appears to play a secondary role in shaping the large-scale damping pattern. In addition, the damping rate increases with background wind speed, indicating that wind speed may modulate eddy-induced SSTA patterns by enhancing turbulent heat flux feedback. These findings highlight the potential role of air-sea turbulent heat flux damping in shaping regional differences in eddy-induced SSTA patterns and provide a useful perspective for understanding mesoscale air-sea interaction in the northwestern Pacific.