陕甘宁及内蒙古西部地区夏季降水的异常气候特征  

Anomaly features of summer precipitation in eastern part of northwestern China and western Inner Mongolia

作　　者：张智[1] 林莉 梁培[1] 杨侃 

机构地区：[1]宁夏气象信息中心,宁夏银川750002 [2]宁夏气象台,宁夏银川750002

出　　处：《干旱区地理》2009年第4期527-531,共5页Arid Land Geography

基　　金：科技部(2004DIB3J121);中国气象局(CCSF2007-27);中英(2001-BA611B-04-06-01)项目共同资助

摘　　要：利用陕西、甘肃、宁夏和内蒙古西部地区64个气象站1961-2000年夏季（6-8月）降水资料,通过Mann-Kendall法和Morlet小波法分析其空间分布和时间变化特征,并选取5个典型多雨年和5个典型少雨年,用NCEP/NCAR资料进行降水异常的对比分析。结果表明：陕甘宁及内蒙古西部地区夏季降水具有明显的空间差异,东南部降水多、西北部降水少,降水整体呈缓慢增多的趋势,线性趋势为2.3 mm/10 a;1976年前后区域内降水发生突变,存在14-16 a的长周期和2 a、2-4 a和准5 a的短周期。多雨年北半球欧亚500 hPa高度距平场中贝加尔湖至我国西北地区为负距平区,东亚沿海为正距平区;温度距平场中贝加尔湖地区为负距平区,距平零线位于西北地区东部。少雨年北半球欧亚500 hPa高度距平场中冷空气主体偏北,贝加尔湖至我国西北地区为正距平区,东亚沿海为负距平区;温度距平场中冷空气活动的区域偏北,贝加尔湖至我国西北地区为正距平区。This paper analyzed the spatial distribution and temporal change of the summer precipitation （Jun. to Aug. ） in the eastern part of northwest China and western Inner Mongolia, using Mann - Kendall and Morlet, based on the monthly data of the summer precipitation from 64 representative weather stations during the period of 1961 - 2000, and compared the relationships between the summer precipitation and the data at NCEP/NCAR 500 hPa in the typical 5 years with high precipitation and the typical 5 years with low precipitation. The results indicated that there was a significant spatial difference of summer precipitation in the eastern part of northwest China and western Inner Mongolia, and the long-term overall trend of the summer precipitation in the eastern part of northwest China and western Inner Mongolia was increased at a rate of 2.3 mm per 10 years. The abrupt change of the summer precipitation occurred in 1976, and had the periods of 14 - 16 and 2 -4 and quasi-5 years oscillations. There were negative anomaly fields of 500 hPa Height in high-precipitation years between the Baikal and northwestern China, the positive anomaly fields were over the coast of eastern Asia, and there were negative anomaly fields of 500 hPa Temperature in the Baikal, the zero-line was over the Eastern of northwestern China. The cold-air was to the north- ern region at 500 hPa Height anomaly field in low-precipitation years, there were positive anomaly fields between the Baikal and northwestern China, the negative anomaly fields were over the coast of eastern Asia, and there were positive anomaly fields of 500 hPa Temperature between the Baikal and northwestern China.

关 键 词：陕甘宁 内蒙古 夏季降水量 气候变化 

分 类 号：P426.61[天文地球—大气科学及气象学]