In general,a mesoscale cyclonic(anticyclonic)eddy has a colder(warmer)core,and it is considered as a cold(warm)eddy.However,recently research found that there are a number of"abnormal"mesoscale cyclonic(anti...In general,a mesoscale cyclonic(anticyclonic)eddy has a colder(warmer)core,and it is considered as a cold(warm)eddy.However,recently research found that there are a number of"abnormal"mesoscale cyclonic(anticyclonic)eddies associated with warm(cold)cores in the South China Sea(SCS).These"abnormal"eddies pose a challenge to previous works on eddy detection,characteristic analysis,eddy-induced heat and salt transports,and even on mesoscale eddy dynamics.Based on a 9-year(2000–2008)numerical modelling data,the cyclonic warm-core eddies(CWEs)and anticyclonic cold-core eddies(ACEs)in the SCS are analyzed.This study found that the highest incidence area of the"abnormal"eddies is the northwest of Luzon Strait.In terms of the eddy snapshot counting method,8620 CWEs and 9879 ACEs are detected,accounting for 14.6%and 15.8%of the total eddy number,respectively.The size of the"abnormal"eddies is usually smaller than that of the"normal"eddies,with the radius only around 50 km.In the generation time aspect,they usually appear within the 0.1–0.3 interval in the normalized eddy lifespan.The survival time of CWEs(ACEs)occupies 16.3%(17.1%)of the total eddy lifespan.Based on two case studies,the intrusion of Kuroshio warm water is considered as a key mechanism for the generation of these"abnormal"eddies near the northeastern SCS.展开更多
The responses of the upper ocean to Typhoon Haitang in July 2005 are investigated using Argo float and multiplatform satellite data.The results show decreasing sea surface temperature(SST),a deepening of the mixed lay...The responses of the upper ocean to Typhoon Haitang in July 2005 are investigated using Argo float and multiplatform satellite data.The results show decreasing sea surface temperature(SST),a deepening of the mixed layer depth(MLD),and enhanced Chlorophyll-a(Chl-a)concentration.Two extreme cool regions are identified.While the magnitude of SST cooling in the two regions is similar,the biological response(Chla enhancement)differs.To facilitate comparisons,the region to the northeast of Taiwan is defined as region A and the region east of Taiwan as region B.Ekman pumping and the intrusion of the Kuroshio play an important role in the enhancement of Chl-a in region A.Cold eddies provide the material source for the formation of the cold center in region B,where mixing is dominant.Because of the relatively high translation speed(5 m/s)in region B,Ekman pumping has little influence on the cooling and Chl-a enhancement processes.Moreover,the MLD is shallower than the nutricline,which means that mixing does not result in a marked increase in nutrients in the euphotic layer(where the nutrient concentration is uniformly depleted).Sea temperatures,in contrast,gradually decrease with depth below the bottom of the mixed layer.In contrast to region A,region B showed no significant enhancement of Chl-a but strong SST cooling.展开更多
基金The National Natural Science Foundation of China under contract Nos 41906008,41806039,41806030,42076021,41676010 and 41706205the State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences under contract Nos LTO1902 and LTO1807+9 种基金the Strategic Priority Research Program of Chinese Academy of Sciences under contract No.XDB42000000the Youth Innovation Promotion Association CAS under contract No.2017397the Pearl River S&T Nova Program of Guangzhou under contract No.201806010105the Open Fund of State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of OceanographyMNR under contract No.QNHX2022the Startup Foundation for Introducing Talent of Nanjing University of Information Science&Technology under contract No.2019r049the Startup Foundation for Introducing Talent of Zhejiang Ocean Universitythe National Key Research Programs of China under contract Nos2016YFC1401407 and 2017YFA0604100the National Programme on Global Change and Air-Sea Interaction under contract Nos GASIIPOVAI-03 and GASI-IPOVAI-05the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)under contract No.311020004。
文摘In general,a mesoscale cyclonic(anticyclonic)eddy has a colder(warmer)core,and it is considered as a cold(warm)eddy.However,recently research found that there are a number of"abnormal"mesoscale cyclonic(anticyclonic)eddies associated with warm(cold)cores in the South China Sea(SCS).These"abnormal"eddies pose a challenge to previous works on eddy detection,characteristic analysis,eddy-induced heat and salt transports,and even on mesoscale eddy dynamics.Based on a 9-year(2000–2008)numerical modelling data,the cyclonic warm-core eddies(CWEs)and anticyclonic cold-core eddies(ACEs)in the SCS are analyzed.This study found that the highest incidence area of the"abnormal"eddies is the northwest of Luzon Strait.In terms of the eddy snapshot counting method,8620 CWEs and 9879 ACEs are detected,accounting for 14.6%and 15.8%of the total eddy number,respectively.The size of the"abnormal"eddies is usually smaller than that of the"normal"eddies,with the radius only around 50 km.In the generation time aspect,they usually appear within the 0.1–0.3 interval in the normalized eddy lifespan.The survival time of CWEs(ACEs)occupies 16.3%(17.1%)of the total eddy lifespan.Based on two case studies,the intrusion of Kuroshio warm water is considered as a key mechanism for the generation of these"abnormal"eddies near the northeastern SCS.
基金supported by the National Natural Science Foundation of China(40976011)the National Basic Research Program of China(2013CB430300)the Public Science and Technology Research Funds Projects of Ocean(201105018)
文摘The responses of the upper ocean to Typhoon Haitang in July 2005 are investigated using Argo float and multiplatform satellite data.The results show decreasing sea surface temperature(SST),a deepening of the mixed layer depth(MLD),and enhanced Chlorophyll-a(Chl-a)concentration.Two extreme cool regions are identified.While the magnitude of SST cooling in the two regions is similar,the biological response(Chla enhancement)differs.To facilitate comparisons,the region to the northeast of Taiwan is defined as region A and the region east of Taiwan as region B.Ekman pumping and the intrusion of the Kuroshio play an important role in the enhancement of Chl-a in region A.Cold eddies provide the material source for the formation of the cold center in region B,where mixing is dominant.Because of the relatively high translation speed(5 m/s)in region B,Ekman pumping has little influence on the cooling and Chl-a enhancement processes.Moreover,the MLD is shallower than the nutricline,which means that mixing does not result in a marked increase in nutrients in the euphotic layer(where the nutrient concentration is uniformly depleted).Sea temperatures,in contrast,gradually decrease with depth below the bottom of the mixed layer.In contrast to region A,region B showed no significant enhancement of Chl-a but strong SST cooling.