Abstract Wind stress at the sea surface is the main mechanical energy source for large‐scale ocean circulation. Quantifying this energy transfer—Wind Power Input (wind power input WPI)—depends strongly on whether wind stress is based on absolute winds or on relative winds that account for the difference between wind and surface current. Ignoring the surface current causes a large bias: WPI is overestimated by ∼58% within mesoscale eddies in the Kuroshio Extension (KE), far higher than the regional mean bias of 17%–35% reported earlier. Relative wind stress has traditionally been considered to be related to a so‐called “eddy killer” effect, that is, the wind usually weakens the kinetic energy of mesoscale eddies; however, recent studies indicate that winds can also enhance eddy development. Based on a coupled air‐sea data set of 6,670 eddies derived from satellite and reanalysis data (1993–2018), we analyzed eddy lifecycles to evaluate wind‐eddy interactions. The results indicate that anticyclonic eddies generally receive more wind energy than cyclonic eddies, with input strongest in winter and weakest in summer. Notably, WPI exhibits a distinct lifecycle dependence: energy input peaks during the generation stage, declines rapidly during maturity, and remains weak during decay while retaining its initial sign. This pattern indicates that early wind‐eddy coupling exerts a persistent influence, followed by a negative feedback in which initial energy input strengthens eddies, but subsequent sea surface temperature and heat flux changes weaken local winds, promoting decay. These findings improve our understanding of wind‐eddy energetics in the KE region and offer refined approaches for estimating wind energy input, with important implications for climate model parameterizations.
Ji et al. (Sun,) studied this question.