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投稿时间：2012-08-27 修订日期：2013-05-06
投稿时间：2012-08-27 修订日期：2013-05-06
中文摘要: 对1951—2007年华南地区18站春季（3—5月）降水进行EOF分析，发现华南春季降水的空间分布具有全区一致性、东西反位相、南北反位相及东北—西南反位相等特点。第二特征向量主要反映了华南春季降水的纬向非均匀分布特征，据此将华南春季降水型分为西涝东旱型和西旱东涝型，并利用NCEP再分析资料对春季降水的纬向分布异常年的大气环流背景特征进行了研究。结果发现：在西涝东旱年，华南西北部存在海平面气压场和高度场的正异常中心，有利于冷空气的南下，而该正异常中心的南部出现负异常，华南东部及其东部海面上呈现范围较大的气压场和高度场正异常，华南西部盛行东南风异常，华南东部存在东北风距平，风场和水汽输送场在华南西部表现为异常辐合，在华南东部表现为异常辐散，因此造成了华南西部降水的偏多和东部降水的偏少。同时，850 hPa涡度场、200 hPa散度场、850 hPa垂直速度场和1000 hPa温度场也均呈现出有利于华南西部降水增多和东部降水减少的环流形势。在西旱东涝年，情况基本相反。
Abstract:The spring (March to May) precipitation of 18 stations over South China during the period of 1951-2007 are analyzed by using the method of EOF analysis. The results show that the spatial distribution of spring precipitation over South China shows 4 main patterns that are the consistency of the whole region, anti phase between east and west, anti phase between north and south, anti phase between northeast and southwest etc. The second eigenvector of the spring rainfall in South China mainly reflects the zonal distribution of non uniform, so the spring rainfall pattern in South China are divided into the type of west flood and east drought, east flood and west drought. The characteristics of its associated atmospheric circulation background in the zonal distribution of spring precipitation anomalies years are analyzed by using NCEP reanalysis data, and the results show that, in the west flood and east drought years, an positive anomaly center of sea level pressure field and height field at 850 hPa is located in the northwest of South China, which is beneficial to the cold air down south. A negative anomalous sea level pressure and height at 850 hPa appear in the south of this positive center, and there presents a positive anomalous sea level pressure and height at 850 hPa in the east of South China and its eastern sea area. An southeast wind anomaly occurs in the west of South China, while there is an anomalous northeast wind in the east of South China. The wind field and water vapor transport field present abnormal convergence in the west of South China, but in the east of South China they perform an abnormal divergence, causing more precipitation in the west of South China but less precipitation in the east of South China. In the meantime, vorticity field at 850 hPa, divergence field at 200 hPa, vertical velocity field at 850 hPa and temperature field at 1000 hPa all show the circulation situation that is favorable for increase of precipitation in the west of South China and decrease of precipitation in the east of South China. In the west drought and east flood years, the situation is basically opposite.
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基金项目:公益性行业(气象)科研专项(GYHY201206041)、国家自然科学基金青年科学基金项目(41105073)和中国气象局成都高原气象研究所高原气象开放基金课题(LPM2012004)共同资助
| 作者 | 单位 |
| 李宏毅 | 中国气象局气象干部培训学院，北京 100081 中国科学院大气物理研究所国际气候与环境科学中心，北京 100029 |
| 林朝晖 | 中国科学院大气物理研究所国际气候与环境科学中心，北京 100029 |
| 宋燕 | 中国气象局气象干部培训学院，北京 100081 |
| 陈红 | 中国科学院大气物理研究所国际气候与环境科学中心，北京 100029 |
引用文本：
李宏毅,林朝晖,宋燕,陈红,2013.华南春季降水纬向非均匀分布及异常年大气环流特征分析[J].气象,39(12):1616-1625.
LI Hongyi,LIN Zhaohui,SONG Yan,CHEN Hong,2013.Zonal Seesaw Like Distribution of Spring Precipitation over South China and Characteristics of Atmospheric Circulation in Anomalous Climate Years[J].Meteor Mon,39(12):1616-1625.
李宏毅,林朝晖,宋燕,陈红,2013.华南春季降水纬向非均匀分布及异常年大气环流特征分析[J].气象,39(12):1616-1625.
LI Hongyi,LIN Zhaohui,SONG Yan,CHEN Hong,2013.Zonal Seesaw Like Distribution of Spring Precipitation over South China and Characteristics of Atmospheric Circulation in Anomalous Climate Years[J].Meteor Mon,39(12):1616-1625.