Long‐range tracking of thunderstorms using sferic measurements
Long‐range tracking of thunderstorms using sferic measurements
复制标题
使用空间测量对雷暴进行远程跟踪
DOI：
10.1029/2001jd002008
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发表时间：
2002
影响因子：
--
通讯作者：
U. Inan
中科院分区：
文献类型：
--
作者：
T. G. Wood;U. Inan
每一次雷击都会发射一个电磁脉冲，这种脉冲被称为无线电大气脉冲，在地球和电离层之间的波导中传播。谐波的大部分能量都在3hz到30khz的频段内，可以以低损耗传播到几十兆欧米的距离。利用南极帕尔默站的甚低频（VLF）磁场测量，发现源自北美（~ 10,000公里范围）的地磁方位角的测量精度低于1度。对帕尔默站到达方位角的分析可以评估包括北美和非洲在内的全球不同地区发生的风暴的闪电率。到达方位角与来自国家闪电探测网络（NLDN）的闪光水平数据进行了比较，83.6%的与NLDN闪光匹配的序列与这些闪光的预测方位角在2度以内。结果还与基于卫星的光学瞬变探测器（OTD）的数据进行了比较，帕尔默站探测到的闪电到达方位角与世界其他地方发生闪电的位置一致。讨论了一次特定的局域雷暴的地面闪和云闪的相对分布及其相互关系。有证据表明，在帕尔默站检测到云内排放产生的气体。
[1] Each lightning stroke launches an electromagnetic pulse, known as a radio atmospheric or sferic that propagates in the waveguide between the Earth and the ionosphere. Sferics, with most of their energy contained in the frequency band from 3 Hz to 30 kHz, can propagate with low loss to distances of tens of megameters. Using very low frequency (VLF) magnetic field measurements at Palmer Station, Antarctica, the azimuths of sferics originating in North America (∼10,000 km range) are found to be measurable to less than 1 degree accuracy. Analysis of the arrival azimuths at Palmer Station allows the assessment of lightning flash rates of storms occurring in diverse regions of the globe including North America and Africa. Arrival azimuths are compared with flash level data from the National Lightning Detection Network (NLDN) and 83.6% of the sferics that could be matched to NLDN flashes were within 2 degrees of the predicted azimuths for those flashes. Results are also compared with data from the satellite-based Optical Transient Detector (OTD), and the arrival azimuths of sferics detected at Palmer Station are consistent with the location of lightning occurring elsewhere around the world. The relative distribution of and the relationship between ground flashes and cloud flashes are discussed for a specific localized thunderstorm. Evidence that sferics generated by intracloud discharges were detected at Palmer Station is also presented.