JUNE 2003 AMERICAN METEOROLOGICAL SOCIETY | P ositive lightning discharges (flashes) are defined as those effectively transporting a positive charge from a cloud to the earth. It is thought that less than 10% of global cloud-to-ground lightning is positive (e.g., Uman 1987). Lightning discharges (flashes) that transfer to ground both positive and negative charges are termed bipolar lightning di...

A novel early streamer emission (ESE) lightning air terminal system is designed and fabricated. By comparing the intercepted artificial lightning striking numbers of the new ESE lightning protection device and the conventional lightning rod (CLR) lightning protection device in laboratory, the effectiveness of intercepting the artificial lightning strokes by the new ESE lightning protection devi...

one of the most dazzling events in the atmosphere is lightning. during updrafts in the life cycle of cumulus clouds, collision of graupels and ice crystals in the presence of liquid water results in vertical separation of electrical charges and lightning. there are four types of lightening depending on the location of discharge. the first type is cloud-to-ground lightning or fork lightning that...

Distribution lines are often located in areas with high ground flash densities, being therefore subject to lightning-caused power interruptions. This paper presents an overview of the various types of lightning overvoltages that can arise on overhead power distribution networks, as well as typical voltage waveforms. The effectivenesses of the most important methods for mitigating such overvolta...

The housing of zinc oxide lightning arresters are playing major role for discharging the lightning surges. Previously porcelain and silicon rubber housings were mainly used depending on the atmospheric conditions but in practice a lot of problems are faced with these housing. Hence this paper presenting the ZnO blocks performance characterizes with different dielectrics such as air, transformer...

Accurate estimates of tree mortality are essential for the development of mechanistic forest dynamics models, and for estimating carbon storage and cycling. However, identifying agents of tree mortality is difficult and imprecise. Although lightning kills thousands of trees each year and is an important agent of mortality in some forests, the frequency and distribution of lightning-caused tree ...

The effects of lightning on trees range from catastrophic death to the absence of observable damage. Such differences may be predictable among tree species, and more generally among plant life history strategies and growth forms. We used field-collected electrical resistivity data in temperate and tropical forests to model how the distribution of power from a lightning discharge varies with tre...

[1] The transient ELF ( 50–5000 Hz) magnetic field radiated by lightning discharges across North America was continuously measured at Duke University during the summer of 2000. In total, 881 sprite-associated lightning discharges over 17 days were analyzed. We report in detail on 76 sprites for which we could reliably determine the lightning charge moment change from the ELF data at the time of...