Three-Dimensional VHF Lightning Mapping System for Winter Thunderstorms

Nishihashi, Masahide; Shimose, Ken-ichi; Kusunoki, Kenichi; Hayashi, Syugo; Arai, Ken-ichiro; Inoue, Hanako; Mashiko, Wataru; Kusume, Masako; Morishima, Hiroyuki

doi:10.1175/jtech-d-12-00084.1

Cited by 9 publications

(10 citation statements)

References 44 publications

(25 reference statements)

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“…(a), the BOLT source altitude distribution of the summer lightning has large values near altitudes of 8 km, whereas the altitude distribution of the winter lightning has large values near 2 km. This result fits well with previous studies . Morimoto et al .…”

Section: Statistical Comparison Of Winter Lightning To Summer Lightnisupporting

confidence: 93%

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Three‐dimensional radio images of winter lightning in japan and characteristics of associated charge structure

Yoshida

Yoshikawa

Adachi

et al. 2018

IEEJ Transactions Elec Engng

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We conducted lightning observational campaigns using a three‐dimensional (3D) lightning mapper called the Broadband Observation network for Lightning and Thunderstorms (BOLT) and C‐band radar to further understand the distinct characteristics of winter lightning in the coastal area of the Sea of Japan. We succeeded in locating 3D intracloud (IC) flashes, cloud‐to‐ground (CG) flashes, and upward lightning during winter. The basic characteristics of winter lightning, such as leader speeds and charge structure associated with an IC discharge, are similar to summer lightning. A noticeable difference between the winter lightning and the summer lightning is that the altitudes of the source locations associated with winter lightning are substantially lower than those associated with summer lightning. We performed a statistical comparison of winter and summer lightning. This comparison shows that the BOLT source altitude distributions during winter and summer peak at 2.1 and 7.5 km, respectively. Conversely, the distributions of the BOLT temperatures, which are the temperatures corresponding to the BOLT source altitudes, during both winter and summer show similar trends and have large values near −10 °C. These results indicate that a similar charge separation process, likely a noninductive charging mechanism, primarily contributes to thunderstorm electrification during both winter and summer. We show that the horizontal extent of the winter flashes is substantially larger than that of the summer flashes. This result implies that the charge regions in winter thunderstorms cover a wide area and, therefore, produce CG flashes with large charge transfers. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

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Section: Statistical Comparison Of Winter Lightning To Summer Lightnisupporting

confidence: 93%

“…Nishihashi et al . observed a single flash using the VHF locating systems in the Shonai area, which is the same region as this study, and reported that the VHF source altitude distribution peaked near 2 km for one flash, which is similar to the result in this study.…”

Section: Statistical Comparison Of Winter Lightning To Summer Lightnimentioning

confidence: 99%

Three‐dimensional radio images of winter lightning in japan and characteristics of associated charge structure

Yoshida

Yoshikawa

Adachi

et al. 2018

IEEJ Transactions Elec Engng

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“…Throughout several decades, many radio source location systems for lightning discharges have been proposed, designed, and developed in an effort to obtain 2D or 3D images of lightning discharges. VHF mappers have produced detailed images of lightning discharges [e.g., Nishihashi et al ., ] and succeeded in understanding lightning processes [ Thomas et al ., ; Edens et al ., ] and the relationship between lightning discharges and thunderstorm structure [e.g., Emersic et al ., ]. However, lightning mappers for frequencies below VHF (e.g., MF or LF band) have also received attention because of their effective approach to studying narrow bipolar events (NBEs), which are also referred to as compact intracloud discharges (CIDs) [ Smith et al ., ; Nag et al ., ; Wu et al ., ; Liu et al ., ], preliminary breakdown (PB), which is sometimes called initial breakdown [ Nag and Rakov , , ; Baharudin et al ., ; Karunarathne et al ., ], and stepped leaders [ T. Takayanagi et al ., ; Bitzer et al ., ], although lightning mappers for frequencies below VHF have been developed mainly for studying return strokes [e.g., Pinto et al ., ].…”

Section: Introductionmentioning

confidence: 99%

Initial results of LF sensor network for lightning observation and characteristics of lightning emission in LF band

Yoshida

Ushio

et al. 2014

JGR Atmospheres

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We have been developing an LF sensor network called Broadband Observation network forLightning and Thunderstorm (BOLT), to image the structure of lightning discharges in 3D using time of arrival (TOA) technique. This paper documents initial results and characteristics of BOLT source locations for further understanding of LF radiation associated with lightning. Theoretical reduced Chi-square distribution fitted to BOLT observation data indicates a root mean square (rms) timing error of about 200 ns for each sensor. Monte Carlo simulations of BOLT indicate that at an altitude of 5000 m the standard deviations for horizontal differences between a known source and a location that the BOLT algorithm produces are less than 200 m, and vertical differences are less than 400 m in most of the network. Furthermore, comparison of BOLT and VHF source locations arriving at the same site within 5 μs indicates that the average difference for elevation direction is 0.73°with a standard deviation of 3.64°, and that for the azimuth direction is 0.58°with a standard deviation of 1.98°. Lightning flash processes of intracloud (IC) and cloud-to-ground (CG) flashes, including preliminary breakdown pulses, negative leaders, breakdown in the negative charge region (NCR), and an attempted leader, are well imaged by BOLT. Normalized amplitudes in E-field change waveform of BOLT sources associated with negative leaders and breakdown occurred in the NCR do not have significant difference, implying that most BOLT sources in the NCR might be associated with negative recoil leaders.

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“…The Shonai area is located on the coast of the Japan Sea. The project was designed in 2007 to investigate the finescale structure of wind gusts using two X-band Doppler radars and a network of 26 surface weather stations, to develop an automatic strong-gust detection system for railroads (Kusunoki et al, 2008;Inoue et al, 2011;Nishihashi et al, 2013). One of the most notable findings was that most of the strong wind gusts during the winter season were related to the passage of misovortices (Kusunoki et al, 2009) and tornadoes (e.g., Inoue et al, 2011), and most of these had developed over the sea and subsequently made landfall.…”

Section: Introductionmentioning

confidence: 99%