2010年8月葫芦岛高频次暴雨的气候背景与环流形势分析

利用常规气象观测资料和国家气候中心的赤道中东太平洋海表温度、850 hPa纬向风距平和副热带高压脊线的数据,使用天气学分析方法,对2010年8月葫芦岛地区高频次暴雨的气候背景及环流形势进行分析。结果表明:2010年7月以来,赤道中东太平洋海表温度较常年同期偏低1.5～2.5℃,快速进入拉尼娜状态;热带地区低层850 hPa赤道中太平洋出现纬向风的强的负趋势,Walker环流有明显增强的正趋势;副高明显偏强,利于西太平洋暖湿的气流沿副高边缘向我国东北地区输送;3次暴雨过程均具有完整的高低空配置,低层辐合、高层辐散,水汽充沛,具有对流不稳定层结。

Analysis of Climate Background and Circumfluence Situation of High-frequent Rainstorm in Huludao Region in August, 2010

The climate background and circumfluence situation of high-frequent rainstorm in Huludao region in August,2010 were analyzed by using the routine meteorological observation data,the middle-eastern equatorial Pacific sea surface temperature provided by China National Climate Centre,the zonal wind anomaly fields at 850 hPa and subtropical ridge line data,as well as the synoptic analysis method.The results showed that: compared with the same period's temperature in normal year,eastern Pacific sea surface temperature was 1.5~2.5 ℃ lower since July,2010,so eastern equatorial Pacific sea quickly stepped into the La Nina state.Central equatorial Pacific sea at 850 hPa in tropical regions appeared strong and negative zonal winds.Walker circumfluence had significant and enhanced positive trend.The subtropical high was rather strong,which was conducive to the transport of western Pacific warm and humid air flow along the edge of the subtropical high to the northeast area of China.Three rainstorm processes had complete allocation of lower-level convergence and upper-level divergence,and abundant water vapor with convective unstable stratification.