Marine heatwaves(MHWs)—discrete,prolonged episodes of anomalously warm ocean temperatures—have increased markedly in frequency,duration,and intensity under ongoing global warming.These events exert profound ecological,biogeochemical,and socioeconomic impacts,particularly in regions characterized by strong air-sea coupling and pronounced climate variability.The northwestern Pacific has emerged as one of the global hotspots of MHW activity,owing to its complex circulation systems,energetic mesoscale and submesoscale dynamics,and sensitivity to basin-scale climate modes.Over the past decade,rapid scientific progress has substantially advanced understanding of MHW characteristics,driving mechanisms,ecosystem impacts,and future evolution in this climatically critical region.Observational evidence from satellite products,reanalysis datasets,and in situ measurements reveals pronounced spatial heterogeneity in MHW occurrence across the northwestern Pacific.High-intensity and recurrent events frequently appear in the Kuroshio and its extension,the subtropical-subpolar frontal zones,and marginal seas such as the Yellow Sea and East China Sea.These regions are characterized by strong background currents,active eddy fields,and sharp frontal gradients that regulate horizontal advection,vertical heat redistribution,and upper-ocean thermal structure.Consequently,MHWs in this region exhibit strong seasonal,interannual,and decadal variability,as well as substantial diversity in vertical structure,ranging from surface-intensified warming to subsurface-intensified and vertically coherent events.
The mechanisms governing MHWs in the northwestern Pacific arise from complex interactions between local atmospheric forcing and remote climate influences.Local processes—including anomalies in radiative fluxes,latent and sensible heat exchange,mixed-layer stratification,and wind-driven Ekman transport—play critical roles in the initiation and persistence of warm anomalies.Oceanic processes such as warm-water advection,eddy-induced heat convergence,and anomalously stable stratification further amplify or prolong MHW events.In addition,large-scale climate modes influence MHW occurrence throug浨攠獡潴獭捯慳汰敨?慲湩摣?獴略扬浥散獯潮獮捥慣汴敩?灮牳漠捴敨獡獴攠獭?慤瑩瑦特椠扳畵瑲楦湡杣???坩?摤牳椬癣敬牯獵?愠捣牯潶獥獲?瑯楣浥敡?猠捣慩汲散獵?慡湴摩?慮猬獡敮獤猠楴湨来?敭捯潣汬潩杮楥挠慳汴?牵散獴灵潲湥献敉獮?瑲潥?浳畩汮瑧椠灥汶敩?捥潮湣捥甠牨物敧湨瑬?獧瑨牴敳猠獴潨牥猠??摰摯牲整獡獮楣湥朠?瑦栠敭獵敬?捩桳慣污汬敥渠杣敯獵?睬楩汮汧?牡敭煯畮楧爠散?敩硭灡慴湥搠敭摯?慥湳搬?獮畴獥瑲慮楡湬攠摯?潥扡獮攠牶癡慲瑩楡潢湩獬?楴浹瀬牡潮癤攠摭?牳敯灳牣敡獬敥渠瑤慹瑮楡潭湩?潳映?牮攠杳楨潡湰慩汮?瀠牴潨捥攠獳獰敡獴?楡湬?浹漠摣敯汭獰?楥湸琠敡杮牤愠瑶楥潲湴?潣晡?灬桹礠獮楡捴慵汲?愠湯摦?才楈潗杳攮漼换桲放浔楨捥愠汥?景牬慯浧敩督潡牬欠獡?慤渠摢?瑯桧敥?楣湨捥潭物灣潡牬愠瑣楯潮湳?潱晵?敮浣敥牳朠楯湦朠?浈慗捳栠楩湮攠?汨敥愠牮湯楲湴杨?慥灳灴牥潲慮挠桐敡獣?晦潩牣???坥?摩敮瑣敲捥瑡楳潩湮?慬湹搠?灥牬敬搠楤捯瑣極潭湥??扥牤?住癢敳牥慲汶汥?爠敩捭数湡瑣?慳搠癩慮湣捬敵獤?栠慣癯敲?獬椠杢湬楥晡楣捨慩湮瑧氬票?敢湩桴慡湴挠敤摥?畲湡摤敡牴獩瑯慮測摳楨湩杦?潳映?浮愠牳楰湥散?桥敳愠瑤睩慳癴敲?癢慵牴楩慯扮楳氬楲瑥祤?浣整捩桯慮湳椠獩浮猠?楲浩灭慡捲瑹猠?慲湯摤?晣畴瑩當物整?爬楤獩歳獲?楰湴?瑯桮敳?湴潯爠瑦桩睳敨獥瑲敩牥湳?偡慮捤椠晡楬捴??潡湴瑩楯湮畳攠摯?搠整癲敯汰潨灩浣攠湰瑡?潨晷?捹潳漮牓摥楶湥慲瑡敬搠?潸扴獲敥牭癥愠瑡楮潤渠慰汥?湳敩瑳睴潥牮歴猠?案楗杳栠?牵敲獩潮汧甠瑴楨潥渠?浡潴摥攠氲椰渱朰?愠湨摡?楥渠瑣敡牵摳楥獤挠楬灯汮楧渭慬牡祳?物敮獧攠慥牣捯桬?睧楩汣污?戠敤?敳獴獵敲湢瑡楮慣汥?昬潵牮?楥浲灳牣潯癲楩湮杧?灴牨敥搠楶捵瑬楮癥敲?换慩灬慩扴楹氠楯瑦礠?慥湧摩?獮畡灬瀠潥牣瑯楳湹杳?敥晭晳攮捍瑯楲癥敯?慥摲愬灴瑨慥琠楣潯湮?慵湲摲?敮捣潥猠祯獦琠敍浈?浳愠湷慩杴敨洠敯湴瑨?獲琠牣慬瑩敭条楴敥猭?楲湩?瑥桮椠獳?牲慥灳楳摯汲祳?捳桵慣湨朠楡湳朠?潣捥敡慮渠?牥敯杸楹潧湥?ation,acidification,and extreme rainfall-runoff events,raises concerns about compound and cascading impacts under continued warming.
Advances in modeling have improved understanding of both the predictability and projected evolution of MHWs.Seasonal forecasting systems show moderate predictive skill for certain MHW types,particularly those linked to ENSO-related atmospheric patterns or decadal background states.High-resolution coupled models increasingly resolve mesoscale processes,although biases in stratification,boundary currents,and air-sea feedbacks remain.Multi-model projections consistently indicate substantial future intensification of MHWs across the northwestern Pacific,including increased spatial extent,stronger thermal anomalies,and more frequent long-duration events.Nevertheless,uncertainties persist due to differences in model representations of ocean circulation,internal variability,and interactions across spatial scales.
Despite considerable progress,key knowledge gaps remain.Limited subsurface observations restrict understanding of the three-dimensional structure of MHWs,while challenges persist in quantifying the relative contributions of