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Furuno, Akiko; Omori, Ryuta*; Tateoka, Hisanori*; Minakawa, Yuya*; Kurihara, Toshiyuki; Yamamoto, Yoichi; Tomita, Yutaka
Pure and Applied Geophysics, 14 Pages, 2024/00
Times Cited Count：0 Percentile：0.00(Geochemistry & Geophysics)The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) Okinawa radionuclide monitoring station (JPP37) is located on a hill facing the East China Sea at the center of the main island of Okinawa. It occasionally detects Cs-137, although no nuclear facilities are located on the island. This study focused on the detection of Cs-137 at JPP37 and examined the ratio of simultaneous detections at nearby stations of the International Monitoring System (IMS) of the CTBTO and the relationship with Asian dust from inland East Asia. The detection of Cs-137 in JPP37 from 2020 to 2023, which motivated this study, was high in spring. Among the nine IMS radionuclide stations in East Asia, the detections in Beijing, Lanzhou, and Ulaanbaatar, Mongolia, were also high in spring. This suggested a high association with the detection of Asian dust in East Asia. Thus, we confirmed the detection of Cs-137 at nine nearby IMS stations when Asian dust was observed at any of the sites in Japan. In addition, we observed that the detection rates were high in Takasaki, Beijing, Lanzhou, and Ulaanbaatar. It can be inferred that the Cs-137 observed mainly in spring at the IMS particulate radionuclide stations in the East Asian region around Japan were likely to pick up the effects of global fallout conveyed by Asian dust. Thereafter, we conducted a preliminary source estimation analysis for Asian dust arrival near Japan. Atmospheric dispersion simulations explained the detection of Cs-137 at nearby IMS particulate radionuclide stations, assuming that Cs-137 was emitted from the desert, the source of the Asian dust.
Furuno, Akiko; Chino, Masamichi; Otsuka, Akira*; Watanabe, Tomonari*; Matsumura, Masaya*; Suzuki, Yoshito*
Agricultural and Forest Meteorology, 133(1-4), p.197 - 209, 2005/11
Times Cited Count：21 Percentile：54.78(Agronomy)Transoceanic migration of rice planthoppers was precisely simulated by incorporating several parameters related to the flight behavior with a high performance atmospheric dispersion model. The model consists of an atmospheric dynamic submodel and a particle random-walk submodel for atmospheric dispersion. The model also functions in specifying the release area of the migration of planthoppers. Using this model, we carried out a case study simulating the migration of planthoppers to western Japan in mid-June 1998. In the simulation, 56 areas each with a width of two degrees of latitude and longitude were set as tentative take-off areas. The calculated density of immigrants was compared with each observed density by rank correlation coefficients. Possible migration release areas which showed a high correlation to observations were distributed around 23-27N, including Fujian and Taiwan. An air temperature that allowed the planthoppers to fly continuously and flight duration were critical parameters for the simulation results.
Furuno, Akiko; Terada, Hiroaki; Chino, Masamichi; Yamazawa, Hiromi*
Atmospheric Environment, 38(40), p.6989 - 6998, 2004/12
Times Cited Count：20 Percentile：40.56(Environmental Sciences)We have been developing the computer-based emergency response system WSPEEDI which predicts long-range atmospheric dispersion of radionuclides discharged into the atmosphere due to a nuclear accident. The first version of WSPEEDI has a shortage that the spatial and temporal variation of the atmospheric boundary layer was very simply parameterized. Therefore we have developed the new version accomplished with the atmospheric dynamic model, in which the turbulent diffusivity in the mixing layer is calculated with a turbulence closure model. This paper describes the results of performance evaluation of the new version of WSPEEDI by comparing the simulation results with the European Tracer Experiment data. As a result of the verification, it was shown that the increase in the horizontal resolution largely improved the accuracy of the model prediction. The use of the turbulence closure model instead of the simple parameterization largely contributed to improve reproducibility of horizontal distribution of plumes.
Terada, Hiroaki; Furuno, Akiko; Chino, Masamichi
Proceedings from the International Conference on Radioactivity in the Environment (CD-ROM), 4 Pages, 2002/09
The present study aims to expanding the capability of WSPEEDI, so that it can be applied to atmospheric releases of radionuclides in the world for terrorist attack as well as nuclear accident. A terrorist attack would be possible in any time, any place and any scale. Altough WSPEEDI has already had a function to acquire global meteorological forecasts to generate a geographical map at arbitrary region in the world, it had no capability for simultaneous multi-scale predictions. Thus, the combination of models, non-hydrostatic meteorological model MM5 and atmospheric dispersion model GEARN, is introduced to WSPEEDI. MM5 can forecast local and regional meteorological condition simultaneously by domain nesting calculations. By the input of meteorological condition generated by MM5, GEARN can forecast multi-scale environmental contaminations considering detailed boundary layer and precipitation processes. Using this improved WSPEEDI, we made test calculations assuming a nuclear accident or terrorist attack in Asia.
Ebihara, Kenichi; Watanabe, Tadashi
European Physical Journal B, 18(2), p.319 - 327, 2000/11
Times Cited Count：8 Percentile：43.94(Physics, Condensed Matter)no abstracts in English
Yamazawa, Hiromi; Furuno, Akiko; Chino, Masamichi
Atmospheric Environment, 32(24), p.4343 - 4349, 1998/00
Times Cited Count：5 Percentile：17.22(Environmental Sciences)no abstracts in English
Koike, Yoshihiro*; Metoki, Naoto; Kimura, Noriaki*; Haga, Yoshinori; Yamamoto, Etsuji; Onuki, Yoshichika*;
Physics of Strongly Correlated Electron Systems (JJAP Series 11), p.44 - 46, 1998/00
no abstracts in English
Yamazawa, Hiromi; Chino, Masamichi; Furuno, Akiko
ETEX Symp. on Long-Range Atmospheric Transport,Model Verification and Emergency Response, p.191 - 194, 1997/00
no abstracts in English
Yamazawa, Hiromi; Chino, Masamichi
Proc. of 6th Topical Meeting on Emergency Preparedness and Response, 0, p.507 - 510, 1997/00
no abstracts in English
Chino, Masamichi; Ishikawa, Hirohiko; Yamazawa, Hiromi; ; Moriuchi, Shigeru
JAERI 1334, 54 Pages, 1995/09
no abstracts in English
Ishikawa, Hirohiko
Journal of Applied Meteorology, 34(7), p.1653 - 1665, 1995/07
no abstracts in English
Chino, Masamichi; Ishikawa, Hirohiko; Yamazawa, Hiromi;
Nihon Genshiryoku Gakkai-Shi, 37(4), p.312 - 315, 1995/00
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)no abstracts in English
Chino, Masamichi; Ishikawa, Hirohiko; Yamazawa, Hiromi
Radiation Protection Dosimetry, 50(2-4), p.145 - 152, 1993/00
no abstracts in English
Ishikawa, Hirohiko; Yamazawa, Hiromi; Chino, Masamichi; ; ;
Proc. of the Int. Conf. on Radiation Effects and Protection, p.385 - 389, 1992/00
no abstracts in English
