葫芦岛夏季降水特征和大气环流异常分析

利用NCEP/NCAR再分析月平均资料及葫芦岛地区4个气象站1981~2010年的夏季(6~8月)降水资料,研究了葫芦岛地区夏季降水的年际变化特征及其与大气环流的联系。结果表明:近30年来,葫芦岛沿海地区的夏季降水呈线性下降趋势,变化趋势不显著,西部地区呈线性上升的趋势,且变化趋势显著;葫芦岛地区夏季降水量的空间分布为全区一致型。在葫芦岛地区偏涝年份的200 hPa位势高度距平场上,东北地区反气旋性环流异常偏强,西风风速偏大;在偏涝年份的500 hPa位势高度距平场上,中高纬地区存在经向环流,副热带高压势力偏强、位置偏北;在偏涝年份的850 hPa风距平场上,中国东部存在偏南风异常偏强,带来较多的水汽。

Analysis of Summer Precipitation Characteristics and Atmospheric Circulation Anomalies in Huludao

The NCEP/NCAR reanalysis monthly mean data and the summer （ from June to August ） precipitation data of 4 me-teorological stations in Huludao area during 1981~2010 were used to study the interannual variations in summer precipitation and atmospheric circulation.The results showed that：in the past 30 years, the summer rainfall in Huludao coastal region was linearly downward , but the trend was not significant;the summer rainfall in the western region was linearly upward , and the trend was sig-nificant .The spatial distribution of summer precipitation in Huludao area was of all -consistency .On 200 hPa geopotential height a-nomaly field of more precipitation year , Northeastern China had anticyclonic circulation anomalies , which caused larger west wind speed.On 500 hPa geopotential height anomaly field of more precipitation year , the meridional circulation existed in middle -high-latitude area;the influence of subtropical high was relatively strong , and its location was slightly northward .On 850 hPa wind a-nomaly field of more precipitation year , the southward wind in Eastern China was abnormally and relatively strong , which brought more vapor .