Polarity inverted intracloud discharges and electric charge structure of thunderstorm  

作　　者：ZHANG Yijun P.R.Krehbiel LIU Xinsheng 

机构地区：[1]Cold and Arid Regions Environmental and Engineering Research Institute,Lanzhou 730000,China [2]New Mexico Institute of Mining and Technology,Socorro,New Mexico,USA

出　　处：《Chinese Science Bulletin》2002年第20期1725-1729,1761-1763,共8页

基　　金：This work was supported by the Chinese Academy of Sciences (Grant No. KZCX2-201) ;the National Natural Science Foundation of China (Grant No. 49975003);the Key Project (Grant No. 40135010).

摘　　要：The three-dimensional spatial and temporal development of impulsive VHF radiation events during lightning discharges has been analyzed based on the data measured by the lightning mapping array (LMA) system with high space and time resolution. The results indicate that intracloud discharges in the thunderstorm with a normal tripole charge structure occur not only between the upper positive and middle main negative charge region, but also with inverted polarity between the lower positive and middle main negative charge region. The polarity-inverted discharge originates from the middle negative charge and propagates downward to the lower positive region, where then the discharge develops horizontally. The characteristics of the discharge are similar to that of normal intracloud discharge except the polarity opposite. The results further confirmed the existence of the lower positive charge region involved in the lightning discharge. It was also found that the inverted charge structure opposite to theThe three-dimensional spatial and temporal development of impulsive VHF radiation events during lightning discharges has been analyzed based on the data measured by the lightning mapping array (LMA) system with high space and time resolution. The results indicate that intracloud discharges in the thunderstorm with a normal tripole charge structure occur not only between the upper positive and middle main negative charge region, but also with inverted polarity between the lower positive and middle main negative charge region. The polarity-inverted discharge originates from the middle negative charge and propagates downward to the lower positive region, where then the discharge develops horizontally. The characteristics of the discharge are similar to that of normal intracloud discharge except the polarity opposite. The results further confirmed the existence of the lower positive charge region involved in the lightning discharge. It was also found that the inverted charge structure opposite to the normal polarity appears in some storms or at a certain stage of the storm development. In the storm with a polarity inverted charge structure, a main positive charge region is located at the middle part and a negative charge at the upper part of the storm. The intracloud discharges occurred between them are of inverted polarity, showing the existence of a polarity inverted charging mechanism in storms and the complexity of storm charge structure.

关 键 词：intracloud DISCHARGE CHARGE STRUCTURE of THUNDERSTORM polarity INVERTED discharge. 

分 类 号：P427[天文地球—大气科学及气象学]