末次间冰期南半球西风急流变化的模拟研究  

RESPONSES OF WESTERLY JETS OVER THE SOUTHERN HEMISPHERE DURING THE LAST INTERGLACIAL BASED ON PMIP4 MODELS

作　　者：江南萱 燕青[1,3] 王会军 JIANG Nanxuan;YAN Qing;WANG Huijun(Nansen-Zhu International Research Centre,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029;University of Chinese Academy of Sciences,Beijing 100049;Key Laboratory of Meteorological Disaster/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology,Nanjing 210044,Jiangsu)

机构地区：[1]中国科学院大气物理研究所竺可桢-南森国际研究中心,北京100029 [2]中国科学院大学,北京100049 [3]南京信息工程大学气象灾害教育部重点实验室/气象灾害预报预警与评估协同创新中心,江苏南京210044

出　　处：《第四纪研究》2023年第4期977-988,共12页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:42022036);科技部第二次青藏高原综合科学考察研究项目(批准号:2019QZKK0101)共同资助。

摘　　要：研究末次间冰期气候变化有助于加深理解变暖情景下气候的变化规律及其对轨道参数变化的响应特征。本研究利用国际古气候模拟对比计划第四阶段的多模式结果,分析了南半球副热带西风急流(200 hPa)与副极地西风急流(850 hPa)在末次间冰期的变化特征及机制。多模式集合平均结果表明,末次间冰期夏季南半球副热带西风急流相较于工业革命前位置偏北(+2.5°),强度偏弱(-5.3%);南半球副极地西风急流也存在类似的变化特征(+1.1°/-7.4%)。在冬季,末次间冰期南半球副热带西风急流相较于工业革命前南移增强(-0.8°/+5.6%),而南半球副极地西风急流北移增强(+0.8°/+4.2%),并且不同洋盆上空的急流具有不同的变化特征。副热带急流与副极地西风急流位置与强度的变化分别与对流层中高层与低层的斜压稳定性的变化相联系。此外,热带非绝热加热与中纬度Rossby波传播的共同作用造成了南印度洋西侧与东侧、高层与低层西风急流反向变化的结果,这种反向变化得到了降水重建的支持。Deciphering climate change during the Last Interglacial(LIG)can advance our knowledge on its response to Earth's orbit in a warmer⁃than⁃present world.Based on the Paleoclimate Modelling Intercomparison Project Phase 4,we investigate variations of the subtropical westerly jet(STJ,200 hPa)and subpolar westerly jet(SPJ,850 hPa)over the Southern Hemisphere during the LIG relative to the preindustrial period(PI).Results showed that the STJ was located more northward(+2.5°)and weakened(-5.3%)in summer during the LIG,as well as the SPJ in summer(+1.1°/-7.4%).To be more specific,the STJ(SPJ)over the south Atlantic,Indian,and Pacific Oceans moved northward by 0.7°,2.0°and 4.9°(1.3°,1.5°and 0.7°),and the intensity changed by-1.9%,-5.0%and-9.0%(+0.2%,-4.6%and-15.4%),respectively.Moreover,in winter,the STJ moved southward and intensified(-0.8°/+5.6%)during the LIG,whereas the SPJ shifted northward and intensified(+0.8°/+4.2%),with the STJ and SPJ over different ocean basins exhibiting diverse responses in winter.The STJ was southward displaced and intensified over the South Atlantic(-2.3°/+17.7%),whereas moved northward and weakened over the South Pacific(+0.4°/-3.8%),with antiphase variations over the west and east of the South Indian Ocean(-1.7°/+11.4%over the west and+0.26°/-1.9%over the east).The SPJ over the South Pacific and South Atlantic were both located more northward and intensified during the LIG by+1.2°/+4.0%and+1.8°/+11.1%,respectively.The out⁃of⁃phase changes of the SPJ were still observed over the South Indian Ocean by+1.3°/-5.2%and-1.5°/-5.4%over the west and east.Variations of the STJ and SPJ were linked with changes in the baroclinic instability measured by the maximum Eady's growth rate in the mid⁃upper and lower troposphere,respectively.Additionally,the out⁃of⁃phase changes in the STJ and SPJ over the western and eastern Indian Ocean during the LIG in winter,supported by reconstructed precipitation,were jointly determined by the tropical diabatic heating/cooling and the ho

关 键 词：末次间冰期 南半球 副热带西风急流 副极地西风急流 

分 类 号：P467[天文地球—大气科学及气象学]