摘要
文中利用热带测雨卫星 (TRMM )搭载的测雨雷达 (PR)、闪电成像仪 (LIS)、GOES卫星红外通道辐射亮温(TBB)对 2 0 0 3年淮河汛期一锋面气旋系统的两个时次的探测结果 ,分析研究了降水结构及闪电活动 ,并与“98.7.2 0”武汉附近地区中尺度强降水的结构和闪电活动进行了比较。GOES的TBB、降水系统中的对流降水与层云降水比例、闪电活动频数随时间的变化均能表征锋面气旋系统的发展。TRMMPR探测结果表明 :冷锋降水狭窄细长 ,且均为强对流降水 (特别在冷锋加强时 ) ;暖锋宽广 ,且为大片层云降水 ,但其中存在面积不等的强对流降水云团 ;与“98.7.2 0”武汉附近地区中尺度强降水垂直结构的比较表明 ,锋面气旋降水的最大降水率出现在近地面 ,而中尺度强降水的最大降水率出现在低空 (3.0～ 3.5km) ,表明两者之间的降水微物理过程存在差别。TRMMLIS探测结果表明 :闪电活动均发生在冷锋的强对流降水云团中 ,暖锋中虽有强对流降水 ,但无闪电活动 ;闪电活动频数高所对应的降水廓线中、上部存在大量的冰相粒子。
Study has been made on heavy rainfall structures and lightning activities in clod-front cyclone occurred in Huai River reaches observed by TRMM PR and LIS separately in one and half hour on June 22, 2003 when raining season of the year started in the region. Precipitation profile features, lightning locations and its frequencies in this system were investigated and compared with those happened in a mesoscale convective system (MCS) near Wuhan city on July 20, 1998. Results indicate that the enhancing process of cold-front cyclone system can be represented well by TBB observed by GOES, ratio of convective rainfall to stratiform rainfall, lightning locations and its occurring frequency. TRMM PR measurements show strong convective rainfall occurred along a narrow and long cold front, especially when the cyclone was deepening and the cold front was enhanced after one and half hour. On the contrary, a large area of stratiform rains occurred in a wide warm front region although there were several strong convective rain blocks embedding in the wide region. Comparing with the averaged convective profile that had the maximum rainfall rate in the lower atmosphere about 3 km～ 3.5 km in the MCS of '98.7.20', the maximum one in the cold-front cyclone system occurred near the ground surface, which may imply different microphysical processes inside precipitating clouds between the two systems. Results also indicate that many lightning activities can be detected in the narrow cold front region due to strong convective rains occur there. But almost no lightning activities happened in the wide warm front region although there was several strong convective rain blocks in the region. Furthermore, results show that the higher frequency of lightning occurrences attends by a lot of ice droplets in the upper precipitating clouds from patterns of precipitation profiles.
出处
《气象学报》
CAS
CSCD
北大核心
2004年第6期790-802,共13页
Acta Meteorologica Sinica
基金
国家自然科学基金 (4 0 175 0 15
40 3 75 0 18
40 2 3 3 0 3 1
40 2 0 5 0 0 8)
中国科学院知识创新工程重要方向项目基金 (ZKCX2 SW 2 10 )
中国科学院知识创新工程重点项目基金 (KZCX2 2 0 8)
国家教育部留学归国人员科研启动基金
中国气象局科教局应用
