塔克拉玛干沙漠中尺度对流系统的时空分布特征

Geographic distribution and life cycle of mesoscale convective system over Taklimakan desert

采用云图增强和图像叠加的方法,通过对1998-2002年5年GMS-5静止气象卫星红外云图数字资料的普查,共获得33个发生在塔克拉玛干沙漠的中-β尺度的对流系统(MCS),研究了MCS的地理分布及生命史特点。结果表明:空间上沙漠西部和北部是MCS的多发区,季节上,MCS主要出现在春末和整个夏季,以5月最多。时间上MCS具有明显的夜发性,多数MCS形成于午后到午夜(16:00-1:00),夜间至凌晨消散,持续4～6h,生命史偏短。

By using the methods of enhanced infrared image and image superposition, 33 meso - convective sys- tems （MCSs） were found in Taklimakan desert during 1998 -2002 by the GMS -5 satellite infrared images, the geographic distribution and the character of life cycle of MCSs were given. MCSs generated most frequently in the northern and western Taklimakan desert. MCSs occurred from April to July, and more frequently in May. The MCSs of Taklimakan desert were distictly nocturnal, majority occurred from afternoon to midnight, and dissipated from night to dawn, the duration of life cycle was 4 - 6h, the life cycle was shorter.