南海海气CO2交换对两个热带气旋“风泵”的不同响应机理分析  

Different mechanisms of air-sea CO2 exchange responding to“Wind Pump”effects of two tropical cyclones in South China Sea

作　　者：孙庆杨 林静柔 唐丹玲[2,3,6] 潘刚 姜兆玉[4] SUN Qingyang;LIN Jingrou;TANG Danling;PAN Gang;JIANG Zhaoyu(South China Sea Institute of Planning and Environmental Research,State Oceanic Administration,Guangzhou 510300,China;State Key Laboratory of Tropical Oceanography,Guangdong Key Laboratory of Ocean Remote Sensing,South China Sea Institute of Oceanology,Guangzhou 510301,China;Graduate University of Chinese Academy of Sciences,Beijing 100049,China;College of Life Science,Linyi University,Linyi 276000,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai,Guangdong 519082,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 510301,China)

机构地区：[1]国家海洋局南海规划与环境研究院,广州510300 [2]中国科学院南海海洋研究所,热带海洋环境国家重点实验室,广东省海洋遥感重点实验室,广州510301 [3]中国科学院大学,北京100049 [4]临沂大学生命科学学院,临沂276000 [5]南方海洋科学与工程广东省实验室(珠海),珠海519082 [6]南方海洋科学与工程广东省·实验室(广州),广州510301

出　　处：《生态科学》2020年第3期9-16,共8页Ecological Science

基　　金：国家自然科学基金重点项目(41430968);国家自然科学基金青年基金(41506127);广东省基金(2019BT2H594,GML2019ZD0602);中国科学院南海海洋研究所热带海洋环境国家重点实验室开放课题(LTO1604);广东省海洋遥感重点实验室开放课题(2017B030301005-LORS1805,2017B030301005-LORS1807);中国-东盟海上合作基金:全球变化背景下南中国海近海生态系统监测与保护管理示范。

摘　　要：利用实测和遥感数据,对比分析南海海气二氧化碳(CO2)交换对2011年4月热带气旋Tropical Depression One(TDO)和2013年9月热带气旋Wutip(WU)的响应及其机理。结果表明,两个热带气旋过境的“风泵”作用均对海气CO2交换产生显著影响:TDO和WU过境后,海水表层CO2分压(pCO2,sw)分别增加42.56μatm、30.88μatm,TDO过境导致区域海洋由强碳汇(-4.7±1.8)mmol·CO2·m^-2·d^-1变为弱碳源(2.0±3.1)mmol·CO2·m^-2·d^-1,而WU过境使区域海洋由弱碳源(1.9±1.0)mmol·CO2·m^-2·d^-1变为强碳源(4.0±1.6)mmol·CO2·m^-2·d^-1。pCO2,sw的增加均由于次表层富含溶解无机碳(DIC)海水的入侵,但是“风泵”的作用机制不同:TDO过境强风引起的艾克曼抽吸导致水体涌升作用显著,而WU过境导致的垂直混合作用强烈。“风泵”的作用机制差异可归因于热带气旋过境前海水的初始状态和过境时移动速度不同:TDO过境前该海域存在冷涡,强风引起的艾克曼抽吸使次表层海水的向上涌升作用增强;而WU过境前存在暖涡,强风引起的艾克曼抽吸造成次表层海水与下沉的表层水垂直混合。TDO的移动速度慢,对海水的作用时间更长,强风引起的艾克曼抽吸作用更强;而WU移动速度快,短时间强风过境造成的水体垂直混合效应作用更显著。The mechanisms of air-sea carbon dioxide(CO2)exchange responding to Tropical Depression One(TDO)and Wutip(WU)in South China Sea,were studied in the research using both ship measured and satellite data.Results indicated that CO2 fluxes(F)were significantly enhanced by the effect of“wind pump”after the two tropical cyclones.The partial pressure of CO2 in sea surface(pCO2,sw)increased by 42.56μatm and 30.88μatm after the passage of TDO and WU,respectively.The regional ocean changed from a strong carbon sink(-4.7±1.8)mmol·CO2·m^-2·d^-1 to a weak carbon source(2.0±3.1)mmol·CO2·m^-2·d^-1 due to the passage of TDO,while a weak carbon source(1.9±1.0)mmol·CO2·m^-2·d^-1 was changed to a strong carbon source(4.0±1.6)mmol·CO2·m^-2·d^-1 due to the passage of WU.The increase of pCO2,sw due to both tropical cyclone events were consequently from the infusion of deeper subsurface waters,which were rich in dissolved inorganic carbon.However,the mechanisms of“Wind Pump”effects were apparently different,by which a water upwelling process was driven by an Ekman pumping caused by TDO,whereas a strong vertical mixing was driven by strong winds caused by WU,respectively.Such difference was attributed to the difference of the initial oceanographic condition states and the transition speeds of those two tropical cyclones.On the aspect of initial oceanographic conditions,a pre-existed cold eddy before the passage of TDO enhanced the strong Ekman pumping causing upwelling,whereas a pre-existed warm eddy before the passage of WU made a vertical mixing.For the aspect of translation speed,the low translation speed of TDO was slow so that the interaction time was long and leading to a strong Ekman pumping,whereas the speed of WU was fast so that vertical mixing was more significant due to a short-term strong wind transition.

关 键 词：热带气旋 海气CO2交换 艾克曼抽吸 垂直混合 

分 类 号：S157.2[农业科学—土壤学]