As a crucial physical phenomenon in the ocean,cyclonic(anticyclonic)eddies are generally thought to generate cold(warm)sea surface anomaly.However,there are a considerable number of eddies with"abnormal"sea surface temperature,which called anticyclonic cold eddies and cyclonic warm eddies.This study focus on the structural characteristics of the"abnormal"eddies,based on satellite remote sensing data and Argo profile data from 2000 to 2020,the composite structure of temperature anomalies of normal eddies(cyclonic cold eddies,anticyclonic warm eddies)and"abnormal"eddies in the Pacific Ocean and four mid-latitude characteristic regions were analyzed in a comparative manner.Results show that first,about 11％of the anticyclonic eddies in the Pacific Ocean are anticyclonic warm eddies,and about 9％of the cyclonic eddies are cyclonic cold eddies,and the"abnormal"temperature layer exists in the depth shallower than 50 m.The synthetic structure of sea surface temperature anomalies of"abnormal"eddies is the opposite of the normal eddies within the normalized eddy radius,and the degree of temperature anomalies is weaker than that of the normal eddies.Secondly,the sea surface temperature anomalies of the"abnormal"eddies in the Kuroshio Extension region have dipole modes,which is the most different from those of the normal eddies and the other three regional eddies.In vertical direction,the structural differences of the"abnormal"eddies in different regions are shown mainly in the thickness,core depth,and strength of the"abnormal"temperature layer.Thirdly,the"abnormal"eddies with subsurface strengthening characteristics may be formed mainly by eddy pumping and eddy-induced Ekman pumping;and the"abnormal"eddies with surface strengthening characteristics may be formed by mainly eddy-induced Ekman pumping.Lastly,horizontal eddy stirring plays an important role in some regions.This study provides a reference in scientific significance for understanding the phenomenon of"abnormal"eddies and analyzing their generation and dynamical mechanisms.
维普
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