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Title SAFIR operation and evaluation of it's performance

Author(s) Z.-I. Kawasaki, K. Yamamoto, K. Matsuura, P. Richard, T. Matsui, Y. Sonoi and N. Shimokura

Journal Geophysical Research Letters, 21, 12, 1133-1136 (1994)

Abstract SAFIR (Surveillance et d'Alerte Foudre par Interferometrie Radioelectrique) has been equipped and operated in Japan since June 12th, 1991 as a cooperative project among Osaka University, Kansai Electric Power Co. INC. (KEPCO), and the French manufacturer DIMENSIONS. The operational coverage covers Northern Kinki District, Wakasa District, and Hokuriku District. Hokuriku District is well known for its winter thunderstorm activity. The method for the evaluation was to take the cross-correlation between the meteorological radar echo pattern and the distribution pattern of lightning discharges detected by SAFIR. We obtained high cross-correlation coefficients and concluded that the SAFIR locations were shown to have statistically high accuracy. We also show the case study of the occurrence of the lightning strike, which is recorded by KEPCO, to evaluate the usefulness of the warning by SAFIR.

Title Dual Polarization Radar Observation of Thunderclouds in Winter Season

Author(s) Y. Sonoi, Y. Maekawa, Z.-I. Kawasaki, F. Yoshino, S. Fukao

Journal J. Geomag. Geoelectr., 47, 999-1010 (1995)

Abstract The authors investigate the characteristics of thunderclouds associated with lightning phenomena in the winter season using the dual polarization Doppler radar of the Ministry of Construction known as the DND (Dobokuken-Nijuhenpa-Dopper) radar. This paper deals with the discrimination between different types of precipitation particles and presents the relationship between the movement of the particles and lightning processes. Our results suggest that the dual polarization observational mode, detecting both the horizontal radar reflectivity factor (ZH) and the differential reflectivity factor (ZDR), may discriminate between precipitation particles such as graupel or ice crystals, and that the observed radar echoes indicate a close relationship between the contact of these precipitation particles and the lightning process. Also, simultaneous field-mill observations suggest that graupel has negative charge while ice crystals have positive charge in thunderclouds. This electrical phenomenon is well described in terms of recent thunderstorm electrification theories at temperatures below -10淸.

Title	SAFIR operation and evaluation of it's performance
Author(s)	Z.-I. Kawasaki, K. Yamamoto, K. Matsuura, P. Richard, T. Matsui, Y. Sonoi and N. Shimokura
Journal	Geophysical Research Letters, 21, 12, 1133-1136 (1994)
Abstract	SAFIR (Surveillance et d'Alerte Foudre par Interferometrie Radioelectrique) has been equipped and operated in Japan since June 12th, 1991 as a cooperative project among Osaka University, Kansai Electric Power Co. INC. (KEPCO), and the French manufacturer DIMENSIONS. The operational coverage covers Northern Kinki District, Wakasa District, and Hokuriku District. Hokuriku District is well known for its winter thunderstorm activity. The method for the evaluation was to take the cross-correlation between the meteorological radar echo pattern and the distribution pattern of lightning discharges detected by SAFIR. We obtained high cross-correlation coefficients and concluded that the SAFIR locations were shown to have statistically high accuracy. We also show the case study of the occurrence of the lightning strike, which is recorded by KEPCO, to evaluate the usefulness of the warning by SAFIR.

Title	Dual Polarization Radar Observation of Thunderclouds in Winter Season
Author(s)	Y. Sonoi, Y. Maekawa, Z.-I. Kawasaki, F. Yoshino, S. Fukao
Journal	J. Geomag. Geoelectr., 47, 999-1010 (1995)
Abstract	The authors investigate the characteristics of thunderclouds associated with lightning phenomena in the winter season using the dual polarization Doppler radar of the Ministry of Construction known as the DND (Dobokuken-Nijuhenpa-Dopper) radar. This paper deals with the discrimination between different types of precipitation particles and presents the relationship between the movement of the particles and lightning processes. Our results suggest that the dual polarization observational mode, detecting both the horizontal radar reflectivity factor (ZH) and the differential reflectivity factor (ZDR), may discriminate between precipitation particles such as graupel or ice crystals, and that the observed radar echoes indicate a close relationship between the contact of these precipitation particles and the lightning process. Also, simultaneous field-mill observations suggest that graupel has negative charge while ice crystals have positive charge in thunderclouds. This electrical phenomenon is well described in terms of recent thunderstorm electrification theories at temperatures below -10淸.