| 2010年秋、冬季节华北持续性干旱的气候成因分析 |
| |
| 引用本文： | 沈晓琳,祝从文,李明.2010年秋、冬季节华北持续性干旱的气候成因分析[J].大气科学,2012,36(6):1123-1134. |
| |
| 作者姓名： | 沈晓琳 祝从文 李明 |
| |
| 作者单位： | 中国气象科学研究院, 北京 100081 |
| |
| 基金项目： | 国家自然科学基金资助项目40921003、90711003;公益性行业(气象)科研专项GYHY200906017;中国气象科学研究院基本科研业务项目2010Z001、2010Z003;中国科学院战略性先导科技专项XDA05090408 |
| |
| 摘 要： | 利用1951～2011年中国台站观测的逐日降水、温度和美国NCEP/NCAR再分析月平均资料, 本文分析2010年秋、冬季(11月至次年2月)发生在华北地区持续性干旱的大气环流和海温异常特征, 并讨论了北极涛动(AO)和La Ni?a事件对此次干旱事件的影响。分析表明, 2010年发生在华北秋、冬季节的持续性干旱是叠加在降水减少气候趋势之上的一次极端干旱事件, 但本次极端干旱事件主要成因是受到同期较强的AO负位相和La Ni?a事件共同的影响。统计发现:AO的负位相有利于乌拉尔山阻塞高压维持和发展, 而贝加尔湖上空出现负位势高度异常, 导致东亚中高纬度经向环流加强和冷空气向南侵袭。AO负位相可导致贝加尔湖上空气压场偏低并影响冷空气的路径和强度, 进而间接地导致华北地区的干冷气候, 而同期La Ni?a的海温异常分布导致西北太平洋副热带高压偏弱偏南, 抑制了西太平洋水汽向华北地区输送, 从而直接导致该地区的干旱。由于2010年AO负指数和La Ni?a事件较历史干旱年份表现出较强和长时间持续性, 从而导致了锋面位置位于华北以南和华北本次的持续性干旱事件。
|
| 关 键 词： | 华北干旱 极端气候事件 北极涛动 LaNi?a事件 |
| 收稿时间： | 2011/10/18 0:00:00 |
| 修稿时间： | 2012/5/16 0:00:00 |
Possible Causes of Persistent Drought Event in North China
during the Cold Season of 2010 |
| |
| SHEN Xiaolin,ZHU Congwen and LI Ming.Possible Causes of Persistent Drought Event in North China
during the Cold Season of 2010[J].Chinese Journal of Atmospheric Sciences,2012,36(6):1123-1134. |
| |
| Authors: | SHEN Xiaolin ZHU Congwen and LI Ming |
| |
| Institution: | Chinese Academy of Meteorological Sciences, Beijing 100081 |
| |
| Abstract: | Anomalies in the sea surface temperature (SST) and atmospheric circulation that are linked to the drought event in North China during the cold season spanning 2010-2011 are discussed. The possible impacts of the Arctic Oscillation (AO) and La Niña are also addressed in the framework of historical analog analysis based on daily station-observed and NCEP/NCAR reanalyzed data sets. The results suggest that the precipitation in North China exhibits a downward trend over the past decades, however, the extreme drought event occurred during the cold season of 2010 has been mainly affected by the negative phase of the AO and the stronger La Niña event. Statistical analysis suggests that during the negative phase of the AO, the geopotential height at 500 hPa decreases around Lake Baikal, the Ural blocking high develops, and meridional circulation anomalies prevail over East Asia. Such high-latitude circulation may enhance the cold surge around Lake Baikal and cause it to shift southward, indirectly causing a cold, dry climate in North China. During La Niña years, however, the cooling of the SST in the Niño3.4 region weakens the western North Pacific subtropical high and directly blocks the southward moisture flux supply. In contrast to historical drought cases, the stronger and persistent negative phases of the AO and the La Niña event pushed the cold front much further south, and the two together caused the persistent drought event in North China during the cold season of 2010. |
| |
| Keywords: | drought in North China extreme climate event Arctic Oscillation La Niñ a |
| 本文献已被 万方数据 等数据库收录！ |
| 点击此处可从《大气科学》浏览原始摘要信息 |
| 点击此处可从《大气科学》下载免费的PDF全文 |
|
