...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Atmospheric chemistry and physics >Lightning characteristics observed by a VLF/LF lightning detection network (LINET) in Brazil, Australia, Africa and Germany
【24h】

Lightning characteristics observed by a VLF/LF lightning detection network (LINET) in Brazil, Australia, Africa and Germany

机译：巴西，澳大利亚，非洲和德国的VLF / LF雷电检测网络（LINET）观察到的雷电特性

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This paper describes lightning characteristics as obtained in four sets oflightning measurements during recent field campaigns in different parts ofthe world from mid-latitudes to the tropics by the novel VLF/LF (very lowfrequency/low frequency) lightning detection network (LINET). The papergives a general overview on the approach, and a synopsis of the statisticalresults for the observation periods as a whole and for one special day ineach region. The focus is on the characteristics of lightning which canspecifically be observed by this system like intra-cloud and cloud-to-groundstroke statistics, vertical distributions of intra-cloud strokes or peakcurrent distributions. Some conclusions regarding lightning producedNOx are also presented as this was one of the aims of the tropicalfield campaigns TROCCINOX (Tropical Convection, Cirrus and Nitrogen OxidesExperiment) and TroCCiBras (Tropical Convection and Cirrus ExperimentBrazil) in Brazil during January/February 2005, SCOUT-O3 (Stratospheric-Climate Linkswith Emphasis on the Upper Troposphere and Lower Stratosphere) and TWP-ICE(Tropical Warm Pool-International Cloud Experiment) during November/December 2005and January/February 2006, respectively, in the Darwin area in N-Australia, and ofAMMA (African Monsoon Multidisciplinary Analyses) in W-Africa duringJune–November 2006.Regional and temporal characteristics of lightning are found to be dependenton orographic effects (e.g. S-Germany, Brazil, Benin), land-sea breezecirculations (N-Australia) and especially the evolution of the monsoons(Benin, N-Australia). Large intra-seasonal variability in lightningoccurrence was found for the Australian monsoon between the strongconvection during build-up and break phases and the weak active monsoonphase with only minor lightning activity. Total daily lightning stroke ratescan be of comparable intensity in all regions with the heaviest events foundin Germany and N-Australia. The frequency of occurrence of such days was byfar the largest in N-Australia. In accordance with radar observed stormstructures, the intra-cloud stroke mean emission heights were founddistinctly different in Germany (8 km) as compared to the tropics (up to12 km in N-Australia). The fraction of intra-cloud strokes (compared to allstrokes) was found to be relatively high in Brazil and Australia (0.83 and0.82, respectively) as compared to Benin and Germany (0.64 and 0.69,respectively).Using stroke peak currents and vertical location information, lightningNOx (LNOx) production under defined standard conditions can be comparedfor the different areas of observation. LNOx production per standard strokewas found to be most efficient for the N-Australian and S-Germanthunderstorms whereas the yield from Brazilian and W-African strokes wasnearly 40% less. On the other hand, the main NO contribution in Brazilwas from intra-cloud (IC) strokes whereas in Benin it was due tocloud-to-ground (CG) components. For the German and Australian strokes bothstroke types contributed similar amounts to the total NO outcome.
机译：本文介绍了通过新颖的VLF / LF（甚低频/低频）雷电检测网络（LINET）在世界各地从中纬度到热带地区最近进行的野战期间从四组雷电测量中获得的雷电特性。本文对该方法进行了总体概述，并对每个区域的整个观察期和某一特定天的统计结果进行了概述。重点是闪电的特征，可以通过此系统专门观察到该特征，例如云内和云对地冲程统计数据，云内冲程的垂直分布或峰值电流分布。还提出了有关闪电产生的NO x 的一些结论，因为这是一月份在巴西进行的热带运动TROCCINOX（热带对流，卷云和氮氧化物实验）和TroCCiBras（热带对流和卷云实验巴西）的目标之一。 2005年2月/ 2005年11月/ 2005年11月和2006年1月/ 2006年2月分别为SCOUT-O3（对流层-平流层，重点放在对流层和平流层以下）和TWP-ICE（热带暖池-国际云实验），分别在达尔文地区在2006年6月至11月期间发生在北澳大利亚，在W-非洲发生了AMMA（非洲季风多学科分析）。 发现闪电的时空特征与地形效应有关（例如S-德国，巴西，贝宁），陆地-海风循环（北澳大利亚），尤其是季风的演变（贝宁，北澳大利亚）。澳大利亚季风在集结期和破裂期的强对流与弱活动季风期之间只有较大的闪电活动，发现季节内的闪电发生较大的季节变化。在德国和北澳大利亚发现的最严重的事件中，所有地区的日总雷击率可能相当。迄今为止，此类日子的发生频率在北澳大利亚州最大。根据雷达观测到的风暴结构，德国（8公里）与热带地区（北澳大利亚最高12公里）相比，云内冲程平均发射高度存在明显差异。与贝宁和德国（分别为0.64和0.69）相比，巴西和澳大利亚的阴云中风比例（与全冲程相比）相对较高（分别为0.83和0.82）。 使用笔划峰值电流和垂直位置信息，可以比较在定义的标准条件下针对不同观察区域的闪电NO x （LNO x ）的产生。发现每标准行程的LNO x 产量对于N-澳大利亚和S-Germanth暴雨最为有效，而巴西和W-African行程的产量却降低了近40％。另一方面，巴西的主要NO贡献来自于云内（IC）笔划，而在贝宁，则主要归因于云对地（CG）组件。对于德国和澳大利亚的中风，两种类型的中风对总NO结果的贡献相似。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号