Zobrazeno 1 - 10
of 137
pro vyhledávání: '"Shin-ichiro Oyama"'
Autor:
Shin-ichiro Oyama, Anita Aikio, Takeshi Sakanoi, Keisuke Hosokawa, Heikki Vanhamäki, Lei Cai, Ilkka Virtanen, Marcus Pedersen, Kazuo Shiokawa, Atsuki Shinbori, Nozomu Nishitani, Yasunobu Ogawa
Publikováno v:
Earth, Planets and Space, Vol 75, Iss 1, Pp 1-13 (2023)
Abstract Ion drag associated with the ionospheric plasma convection plays an important role in the high-latitude thermospheric dynamics, yet changes in the thermospheric wind with geomagnetic activity are not fully understood. We performed a statisti
Externí odkaz:
https://doaj.org/article/12474185579b450188a60e5cd3dcdc32
Autor:
Shin-ichiro Oyama, Heikki Vanhamäki, Lei Cai, Anita Aikio, Michael Rietveld, Yasunobu Ogawa, Tero Raita, Mirjam Kellinsalmi, Kirsti Kauristie, Boris Kozelov, Atsuki Shinbori, Kazuo Shiokawa, Takuo T. Tsuda, Takeshi Sakanoi
Publikováno v:
Earth, Planets and Space, Vol 74, Iss 1, Pp 1-17 (2022)
Abstract The thermospheric wind response to a sudden westward turning of the ion velocity at a high latitude was studied by analyzing data obtained with a Fabry–Perot interferometer (FPI; 630 nm), Dynasonde, and Swarm A & C satellites during a conj
Externí odkaz:
https://doaj.org/article/f1c0d9a93a554d81ae5f7ef5e41bf4bf
Autor:
Vladimir Safargaleev, Tima Sergienko, Keisuke Hosokawa, Shin-ichiro Oyama, Yasunobu Ogawa, Yoshizumi Miyoshi, Satoshi Kurita, Ryochi Fujii
Publikováno v:
Earth, Planets and Space, Vol 74, Iss 1, Pp 1-12 (2022)
Abstract Data from three all-sky cameras in Kiruna and Tjautjas (Sweden) were used to estimate the altitude of pulsating arc-like forms using optical tomography. The event under consideration occurred during the substorm recovery phase and comprised
Externí odkaz:
https://doaj.org/article/5a01860ee85e42b0ac96394a317600b4
Autor:
Yuki Kawamura, Keisuke Hosokawa, Satonori Nozawa, Yasunobu Ogawa, Tetsuya Kawabata, Shin-Ichiro Oyama, Yoshizumi Miyoshi, Satoshi Kurita, Ryoichi Fujii
Publikováno v:
Earth, Planets and Space, Vol 72, Iss 1, Pp 1-9 (2020)
Abstract Using a ground-based five-wavelength photometer, which has been operative in Tromsø, Norway since February 2017, we have statistically analyzed the lifetime of O(1S) to reveal the emission altitude of pulsating aurora (PsA). For the statist
Externí odkaz:
https://doaj.org/article/f9356eb9ae1d46f69d22d578bb9a846c
Publikováno v:
Earth, Planets and Space, Vol 71, Iss 1, Pp 1-8 (2019)
Abstract The average winds in the thermosphere during geomagnetically quiet times are important because they provide a baseline wind in the upper atmosphere, but they remain insufficiently understood at high latitudes. This paper reports the first di
Externí odkaz:
https://doaj.org/article/ad00e429f01c4c2a96743abaa2bdcc8b
Publikováno v:
Earth, Planets and Space, Vol 71, Iss 1, Pp 1-13 (2019)
Abstract Energy input from the magnetosphere during substorms can strongly affect the high-latitude thermosphere. The ionospheric current caused by thermospheric wind variations may also provide a feedback to the magnetosphere. In this study, we inve
Externí odkaz:
https://doaj.org/article/b7081670b2ea4b939964d12fe5d8dd47
Autor:
Mitsunori Ozaki, Yoshizumi Miyoshi, Kazuo Shiokawa, Keisuke Hosokawa, Shin-ichiro Oyama, Ryuho Kataoka, Yusuke Ebihara, Yasunobu Ogawa, Yoshiya Kasahara, Satoshi Yagitani, Yasumasa Kasaba, Atsushi Kumamoto, Fuminori Tsuchiya, Shoya Matsuda, Yuto Katoh, Mitsuru Hikishima, Satoshi Kurita, Yuichi Otsuka, Robert C. Moore, Yoshimasa Tanaka, Masahito Nosé, Tsutomu Nagatsuma, Nozomu Nishitani, Akira Kadokura, Martin Connors, Takumi Inoue, Ayako Matsuoka, Iku Shinohara
Publikováno v:
Nature Communications, Vol 10, Iss 1, Pp 1-9 (2019)
Electron precipitation plays major role in magnetospheric physics and space weather. Here the authors show nonlinear behavior of the wave–particle interaction in the magnetosphere as the evolution of chorus electromagnetic waves detected by the Ara
Externí odkaz:
https://doaj.org/article/a8e8ab072ee84a02aa87d6b8d7a78197
Autor:
Shin-ichiro Oyama, Takuo T. Tsuda, Keisuke Hosokawa, Yasunobu Ogawa, Yoshizumi Miyoshi, Satoshi Kurita, Antti E. Kero, Ryoichi Fujii, Yoshimasa Tanaka, Akira Mizuno, Tetsuya Kawabata, Björn Gustavsson, Thomas Leyser
Publikováno v:
Earth, Planets and Space, Vol 70, Iss 1, Pp 1-7 (2018)
Abstract One of the representative auroral emission lines that radiates from F-region heights and is measurable on the ground is the 777.4 nm line from excited atomic oxygen. This line has been adopted, along with another E-region emission line, for
Externí odkaz:
https://doaj.org/article/8a0e0daf0d8c48dab1dc329c81eb5dc2
Autor:
Kazuo Shiokawa, Yasuo Katoh, Yoshiyuki Hamaguchi, Yuka Yamamoto, Takumi Adachi, Mitsunori Ozaki, Shin-Ichiro Oyama, Masahito Nosé, Tsutomu Nagatsuma, Yoshimasa Tanaka, Yuichi Otsuka, Yoshizumi Miyoshi, Ryuho Kataoka, Yuki Takagi, Yuhei Takeshita, Atsuki Shinbori, Satoshi Kurita, Tomoaki Hori, Nozomu Nishitani, Iku Shinohara, Fuminori Tsuchiya, Yuki Obana, Shin Suzuki, Naoko Takahashi, Kanako Seki, Akira Kadokura, Keisuke Hosokawa, Yasunobu Ogawa, Martin Connors, J. Michael Ruohoniemi, Mark Engebretson, Esa Turunen, Thomas Ulich, Jyrki Manninen, Tero Raita, Antti Kero, Arto Oksanen, Marko Back, Kirsti Kauristie, Jyrki Mattanen, Dmitry Baishev, Vladimir Kurkin, Alexey Oinats, Alexander Pashinin, Roman Vasilyev, Ravil Rakhmatulin, William Bristow, Marty Karjala
Publikováno v:
Earth, Planets and Space, Vol 69, Iss 1, Pp 1-21 (2017)
Abstract The plasmas (electrons and ions) in the inner magnetosphere have wide energy ranges from electron volts to mega-electron volts (MeV). These plasmas rotate around the Earth longitudinally due to the gradient and curvature of the geomagnetic f
Externí odkaz:
https://doaj.org/article/232ecf4e2caa48c9a1d198ff31cfe027
Publikováno v:
Antarctic Record, Vol 57, Iss 3, Pp 339-356 (2013)
This study aimed to develop a methodology for estimating ionospheric conductance at auroral latitudes using data from a multi-wavelength photometer (427.8, 557.7, and 630.0 nm). An advantage of the approach is that the ionosphere is divided into laye
Externí odkaz:
https://doaj.org/article/d3bde42787784b158edf6a20561ab037