2012年全球重大天气气候事件及其成因  

Global Significant Weather and Climate Events in 2012 and the Possible Causes

作　　者：王东阡[1] 王腾飞[1,2] 任福民[1] 龚志强[1] 王遵娅[1] 李多[1] 

机构地区：[1]国家气候中心,北京100081 [2]南京信息工程大学遥感学院,南京210044

出　　处：《气象》2013年第4期516-525,共10页Meteorological Monthly

基　　金：国家自然科学基金项目(41205042);国家重大科学研究计划(2012CB955901);国家重点基础研究发展计划(2012CB417205)共同资助

摘　　要：2012年,全球气温偏高,可能为有观测记录以来的第九个最暖年,北半球经历了有记录以来第二个最热的夏季。年内,2011/2012年拉尼娜事件于2012年初结束,北极海冰范围创历史新低,世界范围内出现了显著的气候异常和极端事件。年初,低温、寒流和暴雪袭卷欧洲和东亚地区;5月,亚马孙河流域因强降水遭遇50年不遇的洪水;6—9月,美国发生1956年以来最严重的干旱;6月以来,多个强台风袭击东亚、东南亚和美国东海岸。全球极端偏暖事件主要出现在欧洲中部和南部、北美洲中部和南部、南美洲南部、亚洲西部、南部和东北部等地;极端偏冷事件主要出现在亚洲大部、欧洲东部和美洲东部的局部等地。欧洲中部、非洲西部、南美洲中南部、南亚、东南亚和东北亚南部等地区出现了极端强降水事件。分析指出,大气环流异常是上述全球重大天气气候事件的直接原因;此外,全球变暖背景下西风基本流偏弱,环流经向度加大、移速减缓和大气环流异常的持续性增强,也为极端事件的发生提供了有利的动力背景。During the first ten months of 2012, above-average temperatures affected most of the globe＇s land surface areas. This is the ninth warmest such period since records began in 1850. The 2011/2012 La Nina ended in the beginning of 2012, and the Arctic sea ice reached its lowest extent on 16 September. During 2012, notable climatic anomalies and extreme events were observed worldwide. Extreme low tem- perature and cold waves hit the Eurasian Continent during late January through mid-February. Extremely severe floods never seen in the past 50 years occurred in the Valley of Amazon River in May. From June to September, North America suffered the most severe drought since 1956. Since June, tropical storms and typhoons attacked East Asia, Southeast Asia and the east coast of America. The global extreme warm e- vents mainly appeared in the central and southern parts of Europe, central and southern parts of North A- merica, southern part of South America, the western, southern and northeastern parts of Asia while the global extreme cold events were mainly experienced in most of Asia, the east of Europe and parts of east- ern America. Besides, extremely severe rainfalls were seen in central Europe, western Africa, central and southern parts of South Americal, South Asia, Southeast Asia and southern part of Northeast Asia. Ana- lyses show that, atmospheric circulation anomalies are the direct causes of above global significant weather and climate events. In addition, with global warming, the westerly basic flow becomes weakening and the meridional circulations in middle and high latitudes becomes strengthening, leading to the enhanced per- sistence of anomalous circulations and favorable dynamic conditions for the formation of climatic anomalies and extreme events.

关 键 词：全球表面气温 寒潮 洪涝 干旱 热带气旋 

分 类 号：P461[天文地球—大气科学及气象学]