中文摘要：

利用2008-2010年夏季（6-8月）NCEP再分析资料,对中国中东部地区中尺度对流系统（MCS）发生前和无MCS发生的环境物理量场进行了诊断对比分析。结果表明,有无MCS发生的环境物理量场明显不同,即：MCS发生前约6 h,中低层为西南风控制,风速明显加大,西太平洋副热带高压加强西伸,南亚高压加强东扩,北边存在明显的高空急流;平均生成位置低层为正涡度,有辐合,高层为负涡度中心,有辐散,整层几乎都有上升运动;平均生成位置附近中低层有来自东部洋面的暖平流,有一条源自孟加拉湾和南海的西南—东北向的水汽输送带;低层不稳定层结较强,中层为较厚中性层结,高层稳定。

英文摘要：

NCEP reanalysis data were used to examine the environment fields prior to mesoscale convective system（MCS）development and null MCS during summer（June-August）of 2008-2010 in central-eastern China.The significant differences were found between environments that support development of MCSs and those that do not support convective organization of MCSs. About 6 hours prior to development for MCS,strong southwest wind controls the middle and low troposphere,and the West Pacific subtropical high strengthens westward.Meanwhile,the South Asia high extends eastward and upper-level jet exists in north. Over the location of MCS generation,positive vorticity and convergence exist in low level,and negative vorticity and divergence exist in upper level,causing ascending motion almost through the whole troposphere. Around the location of MCS generation,there are an obvious warm advection transported from eastern ocean and a southwest-northeast vapor transportation belt whose water vapor is mainly originated from the Bay of Bengal and South China Sea in middle and low troposphere. Meanwhile,intensive unstable at low layer,thick neutral stratification in middle troposphere and stability in upper troposphere exist.