中文摘要：

利用1971—2016年大连地区逐日降水量观测资料和NCEP/NCAR（National Centers for Environmental Prediction/National Center for Atmospheric Research）再分析月平均资料,对2013年7月大连地区降水异常偏多的成因进行了诊断分析。结果表明：2013年7月欧亚中高纬地区维持两脊一槽环流型,乌拉尔山和鄂霍次克海高压异常偏强,贝加尔湖附近低槽稳定维持造成冷空气频繁南下;同时,高空西风急流位置偏北偏强,西太平洋副热带高压明显偏西偏北,东亚夏季风偏强,有利于来自孟加拉湾、南海和西北太平洋的暖湿水汽沿副热带高压外围持续向大连地区输送,冷暖空气在大连地区交汇,形成水汽的异常辐合区,造成大连地区降水异常偏多。高能舌、不稳定层结、异常偏强的上升运动、高空辐散及低空辐合为大连地区降水异常偏多提供了有利的热力和动力条件。

英文摘要：

Based on the daily precipitation observations in Dalian and the NCEP/NCAR（ National Centers for Environmental Prediction/National Center for Atmospheric Research） monthly mean reanalysis data from 1971 to2016,diagnostic analysis of causes of anomalous more precipitation over Dalian during July of 2013 was conducted.The results show that a ＂ two ridge and one trough＂ circulation pattern retains in the middle and high latitudes over the Eurasian Continent. The high pressure over the Ural Mountains and Okhotsk Sea is abnormally stronger,and the low trough maintains steadily near the Baikal Lake,which results in the frequent movements of cold airs to the south. Meanwhile, the more northern and stronger subtropical westerly jets, the more western and northern Western Pacific Subtropical High,and the stronger summer monsoon over the East Asia favor the transport of warm,moist water vapor to Dalian from the Bay of Bengal, the South China Sea and the northwest Pacific Ocean,along the periphery of the subtropical high. Warm and cold airs converge over Dalian,and an abnormal converging area of water vapor formed, leading to anomalous more precipitation in Dalian. Moreover,a high energy tongue,the unstable atmospheric stratification,abnormally stronger upward motions,and the divergence at upper levels and convergence in lower levels provide favorable thermal and dynamic conditions for the anomalous rainfall in Dalian area.