杨美荣,袁铁,郄秀书,潘伦湘. 2011. 西北太平洋热带气旋的闪电活动、雷达反射率和冰散射信号特征分析[J]. 气象学报, 69(2):370-380, doi:10.11676/qxxb2011.032
西北太平洋热带气旋的闪电活动、雷达反射率和冰散射信号特征分析
An analysis of the characteristics of lightning activities, radar reflectivity and ice scattering for tropical cyclones over the western North Pacific
投稿时间:2009-09-02  修订日期:2009-10-27
DOI:10.11676/qxxb2011.032
中文关键词:  热带气旋,闪电,雷达反射率,冰散射,TRMM卫星
英文关键词:Tropical cyclone, Lightning, Radar reflectivity, Ice scattering, TRMM
基金项目:国家杰出青年科学基金获得者“百人计划”专项经费和国家自然科学基金项目(40930949,40774083,40905008)
作者单位
杨美荣 兰州大学大气科学学院半干旱气候变化教育部重点实验室 兰州 730000 
袁铁 兰州大学大气科学学院半干旱气候变化教育部重点实验室兰州 730000 
郄秀书 中国科学院大气物理研究所, 中层大气和全球环境探测重点实验室北京100029 
潘伦湘 中国科学院大气物理研究所, 中层大气和全球环境探测重点实验室北京 100029
中国科学院研究生院 北京 100049 
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中文摘要:
      利用热带测雨卫星(TRMM)携带的测雨雷达(PR)、闪电成像仪(LIS)和微波辐射计(TMI)的同步探测资料,选取1998—2008年登陆中国的46个热带气旋,分析了其不同强度阶段的闪电活动、雷达反射率和冰散射信号的分布特征,以及闪电的发生与雷达反射率和冰散射信号之间的关系。结果发现:强度较弱的热带气旋平均闪电次数相对较高;当强度达到强热带风暴阶段后,强度越强,闪电数量反而越少。热带气旋强度不同,闪电的空间分布也有差别,热带风暴、强台风和超强台风阶段眼壁区闪电密度最大,而其他阶段则在外雨带区密度最大。热带气旋大部分区域被层云和弱对流降水控制,0℃层以上雷达反射率迅速减小,冰散射信号也普遍较弱。虽然热带气旋的眼壁区对流活动最强,但相比于外雨带却较不易发生闪电。在同等大小的雷达反射率下,闪电更易发生在台风和强热带风暴阶段,超强台风阶段发生闪电阈值最高。由于闪电的发生与软雹、冰晶和过冷水等微物理参量以及上升气流速度紧密相关,因此闪电资料可以提供关于热带气旋不同区域的微物理过程和动力过程信息。
英文摘要:
      Using the data from the precipitation radar (PR), lightning imaging sensor (LIS), and passive microwave imaging(TMI) onboard on the Tropical Rainfall Measuring Mission (TRMM) satellite, the characteristics of lightning activities, radar reflectivity and ice scattering of the 46 China landfalling tropical cyclones from 1998 to 2008 are analyzed, and the relationships among lightning occurence and radar reflectivity and ice scattering are investigated. The tropical cyclones are divided into the six intensity periods according to the maximum sustained wind near the eyewall. The results indicate that lightnings are more likely to happen in the weaker intensity period of tropical cyclones compared with the stronger ones. After a tropical cyclone reaches the tropical storms intensity, the stronger it is, the fewer flashes are. There are different spatial distributions of lightning activities in the different intensity periods of tropical cyclones. The largest flash rate occurs in eyewall regions during tropical storm, severe typhoon and super severe typhoon periods, while it occurs in outer rainband regions during the other periods. As a whole, the precipitation in tropical cyclones is dominated by stratiform rains. The radar reflectivity is sharply decreased and the ice scattering signature is weaker as well above the freezing level. Though the strongest convective signatures appear in eyewall regions, there are fewer lightning flashes in eyewall regions than in outer rainband regions. Given the same radar reflectivity, lightning flashes are more likely to occur in typhoon and severe tropical storm periods with a maximum threshold of radar reflectivity found in super typhoon periods. The electrical activities are closely related to ice crystal, graupel, supercooled water and convective updraft, so to some extent, lightning data can give us some information about the microphysical and dynamic processes in tropical cyclones. 
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