Observations of compact intracloud lightning discharges in the northernmost region (51°N) of China
Observations of compact intracloud lightning discharges in the northernmost region (51°N) of China
复制标题
DOI：
10.1002/jgrd.50295
复制
发表时间：
2013-05-27
影响因子：
4.4
通讯作者：
Qin, Zilong
中科院分区：
文献类型：
--
作者：
Lue, Fanchao;Zhu, Baoyou;Qin, Zilong
利用三站宽带电磁场测量网和VHF接收机，在大兴安岭（北纬51度）记录了密集云内放电（CID）。这种类型的闪电放电以前从未在高纬度地区观察到过。在2009年和2010年夏季，共记录了493个CID的正电场脉冲（负电荷上移）发生在31个雷暴，87%（27/31）的CID产生的风暴产生小于20 CID。在北纬51度观测到的CID出现似乎与大多数低纬度地区有很大不同。具体而言，CID仅占140万次记录闪电事件总数的0.034%，并且没有观察到负电场脉冲（正电荷向上移动）的CID。共定位了202个CID，它们聚集在离地5至12公里的高度，平均高度为7.9公里。在15：00-06：00（当地时间）期间，有效电离层高度在75至95公里之间。30 dBZ雷达回波的中位最大高度的对流单体与CID和没有CID分别为10.8和9.4公里。我们推断，一个相对较小的垂直范围内的雷暴云，对流层顶的高度所限制的，以及缺乏强有力的对流涌在高纬度地区可能是负责的缺乏或不存在的CID一般和明显的抑制那些负电场脉冲特别。
Using a three-station wideband electric and magnetic field measuring network in conjunction with VHF receivers, we recorded the so-called compact intracloud discharges (CIDs) in the Greater Khingan Range (51 degrees N) in Northeast China. This type of lightning discharge had never been observed in such high-latitude regions before. During the summer seasons of 2009 and 2010, a total of 493 CIDs with positive electric field pulses (negative charge moving up) occurring in 31 thunderstorms was recorded, with 87% (27/31) of CID-producing storms generating less than 20 CIDs. The CID occurrence observed at 51 degrees N appears to differ significantly from that in most lower latitude regions. Specifically, CIDs accounted only for 0.034% of the total of 1.4 million recorded lightning events, and no CIDs with negative electric field pulses (positive charge moving up) were observed. A total of 202 CIDs was located and they clustered at altitudes ranging from 5 to 12 km above ground level (agl), with a median height of 7.9 km agl. The effective ionosphere heights ranged from 75 to 95 km during the time period of 15:00-06:00 (local time). The median maximum heights of the 30 dBZ radar echo for convective cells with CIDs and without CIDs were 10.8 and 9.4 km, respectively. We infer that a relatively small vertical extent of thunderclouds, limited by the height of the tropopause, and a lack of vigorous convective surges in higher-latitude regions might be responsible for the paucity or absence of CIDs in general and apparent suppression of those with negative electric field pulses in particular.