Title 落雷頻度で見た夏季, 冬季雷の活動
Author(s) 河崎, 松浦, 久保, 山田, 園井
Journal 日本気象学会機関誌”天気”第39巻, 第2号別冊, 21-27 (1992)
Abstract 落雷位置評定システム(LLP)により得られる雷撃点は、通常数キロメートルの評定誤差を含んでいる。そこで本論文では、雷撃点そのものよりも、落雷密度という観点から、夏季雷(1990年7月24日)及び冬季雷(同年12月11日)を論じた。即ち落雷密度は、新たに開発したソフトウェアにより、落雷数の等高線化を行うことにより求めた。その結果、雷活動の時間単位の移動状況が把握でき、レーダ観測の結果との対比も容易となった。特に7月24日の雷活動は、中規模対流性雷活動の様相を呈しており、興味が持たれる。

Title SAFIRによる雷観測結果と気象用レーダエコーとの照合
Author(s) 園井, 河崎, 松浦, 松井, 下倉
Journal 電気学会論文誌B, 113, 9, 987-992 (1993)
Abstract SAFIR (Systeme de Surveillance et d'Alerte Foudre par Interferometrie Radioelectrique) has been equipped and operated since June 12th, 1992 as a cooperative project among Osaka University, Kansai Electric Power Co., Inc. and a French manufacturer DIMENSIONS. The operational coverage includes Northern Kin-ki District, Wakasa District and Hokuriku District. To evaluate the SAFIR system performance, we chose both the summer thunderstorm active area and the winter thunderstorm area. That meant we intended to evaluate the system performance through the summer thunderstorm activity and to apply the system to winter thunderstorm monitoring. As a method for evaluation, the cross correlation between the radar echo pattern and the distribution pattern of lightning discharge was calculated. We obtained the high cross correlation and got to the conclusion that the accurate location of SAFIR was proved statistically. We also show the case study of the occurrence of a ground flash to demonstrate the function of lightning warning by SAFIR.

Title Xバンド二重偏波ドップラーレーダによる冬季雷雲観測結果
Author(s) 園井, 加賀谷, 上田, 河崎, 深尾
Journal 電気学会論文誌B, 116, 4, 417-423 (1996)
Abstract The authors have investigated the internal structure of thunderclouds in winter season using an X band dual polarization Doppler radar in the Wakasa Bay district from 1993. This paper deals with elapsed time transitions of the distribution and the Doppler velocity of precipitation particles in thunderclouds, and the relationship between the heights of radar echo top and of the equivalent potential temperature. In this observation, we have detected the tendency that the region of large echo intensity is maintained in the upper level of thunderclouds about 5 minutes before the lightning discharge, although descends to the lower level about 10 minutes after the lightning discharge. And we have found the relationship between the heights of the echo top and the equivalent potential temperature. Also, referring to the recent electrification theory of thunderclouds, we have discussed the relationship between the temperature of the graupel accumulating region before lightning discharge and the difference of lightning discharge occurring locations, and we have estimated that the difference is caused by the terrain characteristic of the Wakasa Bay.

Title UHF波帯干渉計の製作と雷観測(その1)〜干渉計システムの性能評価〜
Author(s) 和田, 河崎, 松浦, 松井, 武蔵谷, 山本
Journal 電気学会論文誌B, 116, 3, 322-331 (1996)
Abstract A UHF interferometer system for detecting progression of lightning discharges has been accomplished and applied in the observation of winter thunderstorms occurred in Hokuriku area of Japan. This system, operating at center frequency of 327MHz with a bandwidth of 6MHz and the time resolution of 1オs, consists of five antennas which produce long (5l/2) and short (1l/2) baselines in orthogonal directions in a horizontal plane. We confirmed its performance by both experimental tests in a Laboratory and some theoretical simulations. We observed many lightning discharges occurred in winter thunderstorms. The preliminary analysis shows that the system can give us lighting discharges occurred in winter thunderstorms. The preliminary analysis shows that the system can give us the image of the progression of lightning discharges.

Title 冬季雷の気象学的特徴と雷予知技術
Author(s) 道本, 紫村, 松井, 河崎
Journal 電気学会論文誌B, 116, 4, 431-437 (1996)
Abstract The winter thunderclouds that frequently come the southeastern coastal area of the Sea of Japan were investigated by field works, operating two weather radars (one is C-band, another is X-band), the sferics direction-finding system, the car-borne fieldmill, and the SAFIR system. The grade of lightning activity is restricted by the upper air temperature. When cold airmass is advected in lower part of the Hokuriku district, the clouds exhibit weak or no lighting activity. Furthermore, the very good relation between the temporal variation of radar echo and lightning discharges detected by the SAFIR system was confirmed. The SAFIR system can be sufficiently adapted with detecting winter thunderclouds lightning activity in the Hokuriku district.

Title 二重偏波レーダの降水粒子識別機能および雷予知パラメータ
Author(s) 園井, 前川, 河崎, 井川, 深見, 深尾
Journal 電気学会論文誌B, 116, 4, 444-452 (1996)
Abstract The authors observed the thunderclouds in winter season using a C band dual polarization radar in 1989, 1990, 1992 and 1993. We have investigated the distribution and the movement of the precipitation particles, especially graupel and ice crystals which play an important role in the riming electrification theory that is perceived as an potent electric charge generation mechanism in the thunderclouds. As a result, we have reported that there is a close relationship between the mixing of graupel and ice crystals and the lightning discharge. In this paper, we denote the validity of the discriminating method of the precipitation particles, namely graupel and ice crystals by the radar reflectivity (ZH) and the differential radar reflectivity (ZDR) of the dual polarization radar in comparison with the sonde data observed simultaneously. Also, we have proposed two types of predictable parameters for the lightning discharge occurrence based on the discrimination method of the precipitation particles mentioned above, and we discuss the applicability of these predictable parameters.

Title 干渉計による雷放電路の三次元可視化
Author(s) 大貫, 河崎, 和田, 松浦, 松井, 足立
Journal 電気学会論文誌B, 116, 4, 475-481 (1996)
Abstract An imaging of lightning discharge channel in three spatial dimensions is realized by UHF interferometers observation at two stations. These system are operating at center frequency of 327MHz with a bandwidth of 6MHz and the time resolution of 1オs. We observed many lightning discharges in winter storms at Hokuriku area of Japan, and the observed results are analyzed to obtain the lightning channel image. The analysis shows that the system can give us the image of progression of both intracloud and cloud-to-ground discharges in three spatial dimensions, and a strong possibility of clear imaging of lightning channel using interferometers.