Harufumi Tamazawa
Kyoto University
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Publication
Featured researches published by Harufumi Tamazawa.
Earth, Planets and Space | 2015
Hisashi Hayakawa; Harufumi Tamazawa; Akito Davis Kawamura; Hiroaki Isobe
Records of sunspot and aurora observations in pre-telescopic historical documents can provide useful information about solar activity in the past. This is also true for extreme space weather events, as they may have been recorded as large sunspots observed by the naked eye or as low-latitude auroras. In this paper, we present the results of a comprehensive survey of records of sunspots and auroras in the Sòngshǐ, a Chinese formal chronicle spanning the tenth to the thirteenth century. This chronicle contains a record of continuous observations with well-formatted reports conducted as a policy of the government. A brief comparison of the frequency of observations of sunspots and auroras and the observations of radioisotopes as an indicator of the solar activity during corresponding periods is provided. This paper is the first step of our project in which we survey and compile the records of sunspots and auroras in historical documents from various locations and languages, ultimately providing it to the science community as online data.
Publications of the Astronomical Society of Japan | 2016
Hisashi Hayakawa; Kiyomi Iwahashi; Harufumi Tamazawa; Hiroaki Isobe; Ryuho Kataoka; Yusuke Ebihara; Hiroko Miyahara; Akito Davis Kawamura; Kazunari Shibata
The magnetic storm around 1859 September 2, caused by so-called Carrington flare, was the most intense in the history of modern scientific observations, and hence is considered to be the benchmark event for space weather. The magnetic storm caused worldwide observations of auroras even at very low latitudes such as Hawaii, Panama, or Santiago, and the available magnetic field measurement at Bombay, India, showed two peaks: the main was the Carrington event which occurred in day time in East Asia, and a second storm after the Carrington event which occurred at night in East Asia. In this paper, we present a result from surveys of aurora records in East Asia, which provides new information of the aurora activity of this important event. We found some new East Asian records of low latitude aurora observations caused by the storm which occurred after the Carrington event. The size of the aurora belt of the second peak of the Carrington magnetic storm was even wider than usual low-latitude aurora events.
Solar Physics | 2017
Hisashi Hayakawa; Harufumi Tamazawa; Yurina Uchiyama; Yusuke Ebihara; Hiroko Miyahara; Shunsuke Kosaka; Kiyomi Iwahashi; Hiroaki Isobe
A significant carbon-14 enhancement has recently been found in tree rings for the year 994, suggesting an extremely strong and brief cosmic ray flux event. The origin of this particular cosmic ray event has not been confirmed, but one possibility is that it might be of solar origin. Contemporary historical records of low-latitude auroras can be used as supporting evidence of intense solar activity around that time. We investigate previously reported as well as new records that have been found in contemporary observations from the 990s to determine potential auroras. Records of potential red auroras in late 992 and early 993 were found around the world, i.e. in the Korean Peninsula, Saxonian cities in modern Germany, and the Island of Ireland, suggesting the occurrence of an intense geomagnetic storm driven by solar activity.
Publications of the Astronomical Society of Japan | 2016
Akito Davis Kawamura; Hisashi Hayakawa; Harufumi Tamazawa; Hiroko Miyahara; Hiroaki Isobe
We present the result of the survey of sunspots and auroras in
Earth, Planets and Space | 2016
Hisashi Hayakawa; Yasuyuki Mitsuma; Yusuke Ebihara; Akito Davis Kawamura; Hiroko Miyahara; Harufumi Tamazawa; Hiroaki Isobe
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The Astrophysical Journal | 2017
Hisashi Hayakawa; Kiyomi Iwahashi; Yusuke Ebihara; Harufumi Tamazawa; Kazunari Shibata; Delores J. Knipp; Akito Davis Kawamura; Kentaro Hattori; Kumiko Mase; Ichiro Nakanishi; Hiroaki Isobe
, the draft chronicle of
Space Weather-the International Journal of Research and Applications | 2017
Ryuho Kataoka; Hiroaki Isobe; Hisashi Hayakawa; Harufumi Tamazawa; Akito Davis Kawamura; Hiroko Miyahara; Kiyomi Iwahashi; Kazuaki Yamamoto; Masako Takei; Tsuneyo Terashima; Hidehiko Suzuki; Yasunori Fujiwara; Takuji Nakamura
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Publications of the Astronomical Society of Japan | 2017
Hisashi Hayakawa; Yasuyuki Mitsuma; Yasunori Fujiwara; Akito Davis Kawamura; Ryuho Kataoka; Yusuke Ebihara; Shunsuke Kosaka; Kiyomi Iwahashi; Harufumi Tamazawa; Hiroaki Isobe
dynasty, for the period of 1559-1912 CE, as a sequel of the series of works surveying historical sunspot and aurora records, and providing online data to the scientific community regarding the attained results. In total of this
Solar Physics | 2018
Hisashi Hayakawa; Kiyomi Iwahashi; Harufumi Tamazawa; Shin Toriumi; Kazunari Shibata
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Publications of the Astronomical Society of Japan | 2017
Hisashi Hayakawa; Kiyomi Iwahashi; Harufumi Tamazawa; Yusuke Ebihara; Akito Davis Kawamura; Hiroaki Isobe; Katsuko Namiki; Kazunari Shibata
survey, we found 111 records of night-sky luminous events with the keywords such as vapor (