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Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.
Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12
Times Cited Count：7 Percentile：46.67(Geosciences, Multidisciplinary)The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.
Kataoka, Ryuho*; Ebisuzaki, Toshikazu*; Miyahara, Hiroko*; Nimura, Tokuhiro*; Tomida, Takayuki*; Sato, Tatsuhiko; Maruyama, Shigenori*
Gondwana Research, 25(3), p.1153 - 1163, 2014/04
Times Cited Count：23 Percentile：55.41(Geosciences, Multidisciplinary)We propose the Nebula Winter model to explain catastrophic events of the earth, such as mass extinctions and snowball earth events. Encounters with nebulae, such as supernova remnants and dark clouds in the galaxy, can lead to a catastrophic environmental change on the Earth through the destruction of the ozone layer and climate forcing by enhanced fluxes of cosmic rays and cosmic dust particles.
Ebisuzaki, Toshikazu*; Miyahara, Hiroko*; Kataoka, Ryuho*; Sato, Tatsuhiko; Ishimine, Yasuhiro*
Gondwana Research, 19(4), p.1054 - 1061, 2011/06
Times Cited Count：8 Percentile：23.19(Geosciences, Multidisciplinary)We examined the timing of 11 eruptive events that produced silica-rich magma from four volcanoes in Japan (Mt. Fuji, Mt. Usu, Myojin-sho, and Satsuma-Iwo-jima) over the past 306 years (from AD 1700 to AD 2005). Nine of the 11 events occurred during inactive phases of solar magnetic activity (solar minimum), which is well indexed by the group sunspot number. This strong association between eruption timing and the solar minimum is statistically significant to a confidence level of 96.7%. This relationship is not observed for eruptions from volcanoes with relatively silica-poor magma, such as Izu-Ohshima.
Nara, Fumiko*; Yamasaki, Shinichi*; Watanabe, Takahiro; Tsuchiya, Noriyoshi*; Miyahara, Hiroko*; Kato, Takenori*; Minoura, Koji*; Kakegawa, Takeshi*
no journal, ,
High-time resolution measurements of the major and trace inorganic elements, such as Rb and Sr, from the Lake Baikal sediment core was carried out to estimate the weathering response and the material provenance in the lake watershed. The fluctuations of the Rb/Sr ratio and mean grain size (MGS) during the Holocene were corresponding with each other. The similar profiles between the Rb/Sr ratio and the MGS from loess sediment in China have been observed in previous study. These results imply that the Rb/Sr ratio can be used as the proxy to estimate the East Asian winter monsoon intensity.
