Zobrazeno 1 - 10
of 268
pro vyhledávání: '"Keisuke Hosokawa"'
Autor:
Sota Nanjo, Gabriel Arne Hofstra, Kazuo Shiokawa, Atsuki Shinbori, Satonori Nozawa, Keisuke Hosokawa
Publikováno v:
Earth, Planets and Space, Vol 76, Iss 1, Pp 1-14 (2024)
Abstract The phenomenon known as strong thermal emission velocity enhancement (STEVE) is a purple/mauve arc-shaped atmospheric glow observed at lower latitudes of the auroral oval on the duskside. Simultaneous observations using a ground-based camera
Externí odkaz:
https://doaj.org/article/666cea50343b4f7c820a5b78f65c5fca
Autor:
Yuki Obana, Kaori Sakaguchi, Masahito Nosé, Keisuke Hosokawa, Peter Jaquiery, Satoko Saita, Kazuo Shiokawa, Martin Connors, Akira Kadokura, Tsutomu Nagatsuma, Tanja Petersen
Publikováno v:
Earth, Planets and Space, Vol 76, Iss 1, Pp 1-18 (2024)
Abstract This paper describes the instrumentation and the first results of an upper atmospheric observing project conducted in New Zealand. We operate an all-sky aurora camera and a 64-Hz sampling induction magnetometer at Middlemarch, as well as 1-H
Externí odkaz:
https://doaj.org/article/ad33343a04d446b68aea597f7f7c64f5
Publikováno v:
Earth, Planets and Space, Vol 75, Iss 1, Pp 1-13 (2023)
Abstract The explosive eruption of the Hunga Tonga-Hunga Ha’apai volcano on 15 January 2022 generated atmospheric waves traveling around the Earth, which caused ionospheric disturbances on various spatio-temporal scales. A HF Doppler sounding syste
Externí odkaz:
https://doaj.org/article/118d0110d9654cdc994cf3c7d2c55f5c
Autor:
Hiromi Sejima, Keisuke Hosokawa, Hiroyuki Nakata, Jaroslav Chum, Chien-Hung Lin, Jia-Ting Lin
Publikováno v:
Earth, Planets and Space, Vol 75, Iss 1, Pp 1-11 (2023)
Abstract High-Frequency Doppler (HFD) sounders at low-latitudes often detect characteristic oblique spreading Doppler traces in the spectrogram, known as Oblique Spread Structure (OSS). OSS has been expected to be generated by the dispersion of radio
Externí odkaz:
https://doaj.org/article/96428fc374284b5c835b205fc1a598d8
Autor:
Keisuke Hosokawa, Susumu Saito, Hiroyuki Nakata, Chien-Hung Lin, Jia-Ting Lin, Pornchai Supnithi, Ichiro Tomizawa, Jun Sakai, Toru Takahashi, Takuya Tsugawa, Michi Nishioka, Mamoru Ishii
Publikováno v:
Earth, Planets and Space, Vol 75, Iss 1, Pp 1-15 (2023)
Abstract It has long been known that field-aligned irregularities within equatorial plasma bubbles (EPBs) can cause long-range propagation of radio waves in the VHF frequencies such as those used for TV broadcasting through the so-called forward scat
Externí odkaz:
https://doaj.org/article/ca1eb1e6096a4a52a3dbfcd66230f3f7
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:
Larry R. Lyons, Yukitoshi Nishimura, Jiang Liu, Ying Zou, William A. Bristow, Sneha Yadav, Eric Donovan, Nozomu Nishitani, Kazuo Shiokawa, Keisuke Hosokawa
Publikováno v:
Frontiers in Astronomy and Space Sciences, Vol 10 (2023)
Dynamic mesoscale flow structures move across the open field line regions of the polar caps and then enter the nightside plasma sheet where they can cause important space weather disturbances, such as streamers, substorms, and omega bands. The polar
Externí odkaz:
https://doaj.org/article/38098f70844c452fac4b630ea420de7b
Autor:
Sota Nanjo, Satonori Nozawa, Masaki Yamamoto, Tetsuya Kawabata, Magnar G. Johnsen, Takuo T. Tsuda, Keisuke Hosokawa
Publikováno v:
Scientific Reports, Vol 12, Iss 1, Pp 1-12 (2022)
Abstract The activity of citizen scientists who capture images of aurora borealis using digital cameras has recently been contributing to research regarding space physics by professional scientists. Auroral images captured using digital cameras not o
Externí odkaz:
https://doaj.org/article/4dbee1b0faf4462692a49c94f3b59044
Autor:
Ryo Matsushima, Keisuke Hosokawa, Jun Sakai, Yuichi Otsuka, Mitsumu K. Ejiri, Michi Nishioka, Takuya Tsugawa
Publikováno v:
Earth, Planets and Space, Vol 74, Iss 1, Pp 1-13 (2022)
Abstract We carried out a statistical analysis of the propagation characteristics of Es and Medium-Scale Traveling Ionospheric Disturbances (MSTIDs) by combining data of HF Doppler (HFD) sounder and Total Electron Content (TEC) obtained from the GPS
Externí odkaz:
https://doaj.org/article/6110b9a2db1a4266b35068bdb2ce4f17
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