中国东北地区中尺度对流复合体的时空分布特征

普查2005年5月1日至2008年9月30日FY-2C每隔30 min一次的红外云图，根据修正的MCC（Mesoscale Convective Complexes）标准，统计分析中国东北地区出现的MCC变化。结果表明：4 a共出现了22个MCC，其中19个出现在7-8月；东北地区MCC生成源地有明显的地域特点，MCC的生成与大兴安岭的地形密切相关，而辽宁和吉林东部极少生成MCC。中国东北地区MCC平均生命史为9.3 h，比美洲及中国南方地区都短，而≤-52℃和≤-32℃冷云罩面积明显大于以上两个区域；东北地区具有明显的夜发性特征，近85 %的MCC生成于午后到傍晚，15-24时是MCC对流最旺盛的时段。

Spatial and temporal distribution of mesoscale convective complex in Northeast China

A census survey was done using the FY-2C infrared cloud imageries with once every 30 minutes from May 1,2005 to September 30,2008. The variations of the mesoscale convective complex （MCC） in the Northeast China were analyzed based on the amended MCC standards. The results show that there are 22 MCCs during the census survey in the Northeast China and 19 of them appear in July or August. The source region of MCCs is of the significantly regional characters,and the generation of MCC is related to the terrains of Daxing＇anling moun- tain, while few MCCs are found in Liaoning province and the east of Jilin province. The average life time is 9.3 hours in the Northeast China which is shorter than that in America and the South China, while the scales under -52℃ or under -32℃ in the Northeast China are all greater than that in the above two regions. The noctumalism of MCCs is significant in the Northeast China. Among them, 85 % of MCCs generates during afternoon to eve-ning ,and its convective frequent period is from 15：00 to 24：00.