北大西洋-东亚和北亚型遥相关的机制及其对新疆夏季旱涝的影响  

Mechanisms underlying the North Atlantic-East and North Asia pattern and its impact of on the summer drought and flood anomalies in Xinjiang,China

作　　者：樊威伟 马伟强[4,5,6] 胡泽勇 马耀明 杨耀先 韩翔 FAN Weiwei;MA Weiqiang;HU Zeyong;MA Yaoming;YANG Yaoxian;HAN Xiang(Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;Nagqu Station of Plateau Climate and Environment,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Nagqu 852000,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Land-Atmosphere Interaction and its Climatic Effects Group,State Key Laboratory of Tibetan Plateau Earth System,Environment and Resources(TPESRE),Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;College of Atmospheric Science,Lanzhou University,Lanzhou 730000,China;National Observation and Research Station for Qomolongma Special Atmospheric Processes and Environmental Changes,Dingri 858200,China;Ocean College,Zhejiang University,Zhoushan 316021,China)

机构地区：[1]中国科学院西北生态环境资源研究院/中国科学院寒旱区陆面过程与气候变化重点实验室,甘肃兰州730000 [2]中国科学院西北生态环境资源研究院/那曲高寒气候环境观测研究站,西藏那曲852000 [3]中国科学院大学地球与行星科学学院,北京100049 [4]中国科学院青藏高原研究所青藏高原地球系统与资源环境全国重点实验室地气作用与气候效应团队,北京100101 [5]兰州大学大气科学学院,甘肃兰州730000 [6]西藏珠穆朗玛特殊大气过程与环境变化国家野外科学观测研究站,西藏定日858200 [7]浙江大学海洋学院,浙江舟山316021

出　　处：《大气科学学报》2023年第1期30-41,共12页Transactions of Atmospheric Sciences

基　　金：国家自然科学基金资助项目(41830650,91837208);第二次青藏高原综合科学考察研究项目(2019QZKK0103)。

摘　　要：北大西洋-东亚和北亚(简称NAENA)型遥相关是夏季欧亚大陆对流层上层经向风异常的第二主导模态,对欧亚大陆多尺度气候变率有显著影响。本文在分析NAENA型维持的动力学机制的基础上,研究了该遥相关型对新疆夏季旱涝异常的影响及其可能机制。大气波列的涡度收支分析表明,气候态的旋转纬向风引起的扰动涡度平流可以被扰动旋转经向风引起的平均涡度平流所补偿。能量转换过程分析表明,该大气波列有效地从平均流中提取有效位能,通过斜压能量转换过程得以维持。大西洋海温异常三极子模态则是NAENA型维持的重要外强迫因子。回归分析表明NAENA型遥相关能通过促进南疆夏季降水,显著影响新疆的旱涝异常。NAENA型位于中亚的气旋性低压一方面增强了南疆地区的垂直上升运动,同时气旋性环流将更多的水汽输送到该地区,有利于水汽在对流层中低层的异常辐合,进而对南疆的降水有促进作用。The second mode of 200 hPa meridional wind over the Eurasian continent,known as the North Atlantic-East and North Asia(NAENA)pattern,has a significant impact on the multi-scale climatic variability in Eurasia.This paper examined the NAENA pattern’s influence on summer drought and flood anomalies in Xinjiang,China,as well as its possible mechanism,based on an analysis of the NAENA pattern’s maintenance mechanism.The vorticity budget analysis of atmospheric wave train shows that the advection of perturbed vorticity by the climatological rotational zonal wind can be compensated by the advection of mean vorticity caused by the anomalous rotational meridional wind.The energy conversion analysis indicates that the NAENA pattern is maintained mainly through the baroclinic energy conversion from the basic flow with the North Atlantic SST tripolar pattern being the important external driving factor for maintaining the NAENA pattern.Moreover,regression analysis shows that the NAENA pattern can significantly affect drought and flood anomalies in Xinjiang by promoting Southern Xinjiang summer precipitation.When the NAENA pattern is in phase with a cyclone over Central Asia,the vertical ascending motion in Southern Xinjiang tends to be above normal;however,more water vapor is transported into Southern Xinjiang,leading to an anomalous increase in precipitation over Xinjiang.This study is of great significance because it reveals the mechanisms of summer drought and flood in arid areas of northwest China,which is conducive to climate prediction and disaster prevention and mitigation.

关 键 词：遥相关型 新疆降水 维持机制 年际变化 

分 类 号：P426.616[天文地球—大气科学及气象学]