Hiroyo Ohya

Ionospheric disturbances associated with the eruption of Mt. Asama observed by TEC data and HF Doppler sounding

Hiroyuki Nakata, Aritsugu Chonan, Keisuke Hosokawa, Takuya Tsugawa et autres

Abstract Mt. Asama, Nagano Prefecture, Japan, erupted at 11:02 UT on September 1st, 2004. Ionospheric disturbances associated with this eruption were detected using TEC data and HF Doppler observations. It has already been reported that the TEC data obtained from GNSS receivers …

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Properties of EMIC Waves and EMIC Wave‐Driven Electron Precipitation in Subauroral Latitudes Observed at Athabasca, Canada

Asuka Hirai, Fuminori Tsuchiya, T. Obara, Yoshizumi Miyoshi et autres

Abstract Electromagnetic ion cyclotron (EMIC) waves are believed to cause the loss of relativistic electrons from the outer radiation belt into the atmosphere due to pitch angle scattering. However, it is still unclear whether all EMIC waves can scatter relativistic electrons or …

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D-Region Ionospheric Variations Induced by a 2023 Fireball in Hokuriku, Japan, Using OCTAVE VLF/LF Transmitter Signals

Hiroyo Ohya, Fuminori Tsuchiya, Masa‐yuki Yamamoto, Hiroyuki Nakata

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D-region Ionosphere and Space Weather Phenomena: Latest Research and Impacts in AVON Project

Hiroyo Ohya, Fuminori Tsuchiya, Masaharu Nakayama, Yukihiro Takahashi et autres

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Properties of EMIC waves and EMIC wave-driven REP observed in subauroral latitudes

Asuka Hirai, Fuminori Tsuchiya, T. Obara, Yoshizumi Miyoshi et autres

Electromagnetic ion cyclotron (EMIC) waves are believed to cause the loss of relativistic electrons from the outer radiation belt into the atmosphere due to pitch angle scattering. However, it is still unclear whether all EMIC waves can scatter relativistic electrons or which …

jp, us, ca (code pays fourni par la source)

Lower ionospheric resonance caused by Pekeris wave induced by 2022 Tonga volcanic eruption

Hiroyo Ohya, Fuminori Tsuchiya, Tamio Takamura, Hiroyuki Shinagawa et autres

The submarine volcano Hunga Tonga-Hunga Ha'apai erupted explosively on January 15, 2022, offering a unique opportunity to investigate interactions between the atmosphere and ionosphere caused by Lamb and Pekeris waves. However, the resonance of Pekeris waves has not been previously detected. In …

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Variation in the Reflection Height of VLF/LF Transmitter Signals in the D‐Region Ionosphere and the Possible Source: A 2018 Meteoroid in Hokkaido, Japan

Hiroyo Ohya, Takeru K. Suzuki, Fuminori Tsuchiya, Hiroyuki Nakata et autres

Abstract Several studies have examined ionospheric variation associated with meteorites, meteoroids, or meteors based on Global Satellite Navigation System total electron content observations. However, there have been few quantitative studies of the D‐region of the ionosphere (60–90 km), which is associated with …

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Estimation of the Absorption of HF Radio waves for the HF-START Project

Hiroyuki Nakata, Shun Sato, Kornyanat Hozumi, Susumu Saito et autres

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D-region Ionospheric Response to a Fire Ball Using VLF/LF Transmitter Signals

Hiroyo Ohya, Takeru Suzuki, Fuminori Tsuchiya, K. Shiokawa et autres

Meteors and fireballs are known to ionize the D-region and lower E-region ionospheres at 80-120 km heights [1].The fireballs are meteors whose magnitude of brightness is larger than -4 based on the IAU (International Astronomy Union) definition.TID (traveling ionospheric disturbance) associated with …

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Horizontal Inhomogeneity in the D-region Ionosphere During a X-class Solar Flare Using OCTAVE VLF/LF Observations

Masaharu Nakayama, Hiroyo Ohya, Fuminori Tsuchiya, K. Shiokawa et autres

Atmospheric and ionospheric waves induced by the Hunga eruption on 15 January 2022; Doppler sounding and infrasound

Jaroslav Chum, Tereza Šindelářová, Petra Koucká Knížová, Kateřina Podolská et autres

SUMMARY The massive explosive eruption of the Hunga volcano on 15 January 2022 generated atmospheric waves that were recorded around the globe and affected the ionosphere. The paper focuses on observations of atmospheric waves in the troposphere and ionosphere in Europe, however, …

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RESPONSE OF THE D-REGION IONOSPHERE TO FIREBALLS USING VLF/LF TRANSMITTER SIGNALS

Takeru Suzuki, Hiroyo Ohya, Fuminori Tsuchiya, K. Shiokawa et autres

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