中文摘要：

在北京天津区域的对流开始(CI ) 的特征在 20082013 的温暖的季节期间被检验。38877 个 CI 盒子的一个总数被雷雨鉴定识别，追踪，分析，和 nowcasting 算法。CI 盒子在联系地面的上下文被评估，捱过系统，并且打盖子性质。所有 CI 盒子的空间分发证明在 200-m 举起附近有稠密的 CI 活动，它意味着对流暴风雨更容易在山麓丘陵上被触发。从 15001800 ～ 03000600 BT (北京时间) ，高出现的 CI 区域趋于宣传向东南(即，从山脉到平原，然后到海洋) 。在四个本地天气系统之中，当在马槽以后系统有最低 CI 频率时，蒙古的冷旋涡有最高的 CI 频率。为与 CI 的陆地盖子关系，城市的陆地盖子有最高的 CI 密度，森林类型陆地盖子有第二最高的 CI 密度；陆地盖子的这二种类型对 CI 形成更导致。

英文摘要：

Characteristics of convective initiation（CI） in the Beijing-Tianjin region during the warm season of 2008-2013 are examined.A total of 38877 CI cases are identified by a thunderstorm identification,tracking,analysis,and nowcasting algorithm.CI cases are evaluated in the context of associated terrain,weather systems,and land cover properties.The spatial distribution of all CI cases shows that there are dense CI activities around the 200-m elevation,which means that convective storms are more easily triggered over foothills.From 1500-1800 to 0300-0600 BT（Beijing Time）,the high-occurrence CI region tends to propagate southeastward（i.e.,from mountains to plains,then to ocean）.Among the four local weather systems,the Mongolian cold vortex has the highest CI frequency while the after-trough system has the lowest CI frequency.For the land cover relationships with CI,the urban land cover has the highest CI density and the forest-type land cover has the second highest CI density;these two types of land cover are more conducive to CI formation.