| 大气环流系统组合性异常与极端天气气候事件发生 |
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| 引用本文： | 李崇银,杨辉,赵晶晶.大气环流系统组合性异常与极端天气气候事件发生[J].大气科学学报,2019,42(3):321-333. |
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| 作者姓名： | 李崇银 杨辉 赵晶晶 |
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| 作者单位： | 中国科学院大气物理研究所LASG国家重点实验室;国防科技大学气象海洋学院;中国科学院大学 |
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| 基金项目： | 国家重点研发计划（2018YFC1505901）；国家自然科学基金资助项目（41490642） |
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| 摘 要： | 根据2008年1月我国南方发生的持续严重雨雪冰冻灾害、1998年长江流域的特大洪涝灾害和2009/2010年冬季云南的极端干旱灾害的分析结果,再次强调指出,对于一些小概率的极端天气气候事件的发生,大气环流系统的组合性异常起着极其重要的作用。对于2008年的严重雨雪冰冻灾害的发生,多个大气环流系统的组合性异常包括:乌拉尔山阻塞高压和贝加尔湖-巴尔喀什湖的横槽,这为不断有冷空气从西路向南爆发提供了条件;东亚和日本地区的高度正异常使得北方冷空气的势力不是很强,适于锋面在我国南岭及其以北地区较长时间停留,为持续降水确立了背景;西太平洋副高偏强和偏西也对冷空气的向南推进起了阻挡作用;印-缅槽的持续偏强和西太平洋副高的偏强共同使暖湿空气源源不断地输送到华南地区,有利持续降水的发生,为冰冻造成了条件。对于1998年夏季长江流域的特大洪涝的发生,多个环流系统的异常包括:夏季西南季风涌的活动,西太平洋副热带高压活动,北方冷空气活动和青藏高原对流系统东传的共同作用。对于2009/2010年冬季云南的极端干旱灾害的发生,多个环流系统的异常包括:对流层高层中东地区副热带西风急流减弱,影响Rossby波的活动,不利于青藏高原-孟加拉湾槽的建立;西太平洋副热带高压偏强、位置略为偏南,对低层水汽输入云南起到抑制作用;NAO的负异常所导致的遥相关波列异常,使得东亚北方冷空气活动偏东,不易到达云南地区,还使得南支槽偏弱,暖湿气流也不易到达云南地区。ENSO虽然对中国天气气候变化有相当重要的影响,但并非每次异常天气气候事件的发生都是它的直接影响。对于ENSO影响必须具体分析,才能决定它在异常事件、特别是极端天气气候事件中的确切作用。
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| 关 键 词： | 大气环流系统组合性异常 持续雨雪冰冻天气 长江流域洪涝 云南极端干旱 ENSO影响 |
| 收稿时间： | 2019/3/2 0:00:00 |
| 修稿时间： | 2019/3/10 0:00:00 |
Combinational anomalies of atmospheric circulation system and occurrences of extreme weather/climate events |
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| LI Chongyin,YANG Hui and ZHAO Jingjing.Combinational anomalies of atmospheric circulation system and occurrences of extreme weather/climate events[J].大气科学学报,2019,42(3):321-333. |
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| Authors: | LI Chongyin YANG Hui and ZHAO Jingjing |
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| Institution: | State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China;Institute of Meteorology and Oceanography, National University of Defense Technology, Nanjing 211101, China,State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China and State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China;University of Chinese Academy of Sciences, Beijing 100049, China |
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| Abstract: | Based on the analyses of lasting disaster weather of freezing rain and snow over South China during the January of 2008,the catastrophic flood over the Changjiang River basin during the summer of 1998 and the severe drought in Yunnan Province during the winter of 2009/2010,this paper emphasizes again that the combinational anomalies of atmospheric circulation system play important roles to the little probabilistic extreme weather and climate events.For the lasting disaster weather of freezing rain and snow in 2008,the combinational multiple circulation anomalies are clear,including Ural blocking high and a trough from Lake Baikal to Lake Balkhash that offer condition for continual cold air pouring southward from the west passage,and positive geopotential height anomalies over the eastern Asia and Japan that weaken the force of cold air from the north.Thus the front stays longer time over the South Mountain and its north area,which establishes background for continuous raining.Meanwhile,the Northwest Pacific subtropical high extents westward and its intensity also enhances,baring the cold air.The persistent strong Indian-Myanmar Trough and Northwest Pacific subtropical high transport warm and wet air to South China,and it is favorable to the occurrence of continuous rain.Persistent cold air activity and precipitation induce persistent low temperature,which creates conditions for the freezing weather.For the catastrophic flood over the Changjiang River basin in 1998,the combinational multiple circulation anomalies include the southwest monsoon surge,the Northwest Pacific subtropical high and cold air activities in summer,combined with the eastward propagation of convective system of the Tibetan Plateau.For the severe drought in Yunnan Province during the winter of 2009/2010,the combinational multiple circulation anomalies include that the Middle East subtropical jet at upper troposphere weakens,which influences Rossby wave and is unfavorable to the formation of the Tibetan Plateau-Bay of Bengal Trough;The Northwest Pacific subtropical high intensifies and shifts slightly southward,which inhibits the lower-level water vapor transmission into Yunnan;Teleconnection wave train anomaly caused by negative anomaly of NAO makes the cold air activity in the northeast of East Asia locate to the east and be difficult to reach the Yunnan region.It also makes the southern branch trough weak,and the warm and wet air could hardly reach to the Yunnan region.Generally the ENSO has a very important impact on weather and climate variations in China,but the influence is not same in every time and every region.The specific impact of ENSO must be analyzed case by case in order to determine its exact role in anomalous events,especially extreme weather and climate events. |
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| Keywords: | combinational anomalies of atmospheric circulation system lasting weather of freezing rain and snow flood in Changjiang River Basin severe drought in Yunnan ENSO influence |
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