20 Result(s)

Article

Machine learning emulator for physics-based prediction of ionospheric potential response to solar wind variations

Physics-based simulations are important for elucidating the fundamental mechanisms behind the time-varying complex ionospheric conditions, such as ionospheric potential, against unprecedented solar wind variat...

Ryuho Kataoka, Shinya Nakano, Shigeru Fujita in Earth, Planets and Space (2023)

Article

Localized mesospheric ozone destruction corresponding to isolated proton aurora coming from Earth’s radiation belt

Relativistic electron precipitation (REP) from the Earth’s radiation belt plays an important role in mesospheric ozone loss as a connection between space weather and the climate system. However, the rapid (ten...

Mitsunori Ozaki, Kazuo Shiokawa, Ryuho Kataoka, Martin Mlynczak… in Scientific Reports (2022)

Article

PSTEP: project for solar–terrestrial environment prediction

Although solar activity may significantly impact the global environment and socioeconomic systems, the mechanisms for solar eruptions and the subsequent processes have not yet been fully understood. Thus, mode...

Kanya Kusano, Kiyoshi Ichimoto, Mamoru Ishii, Yoshizumi Miyoshi… in Earth, Planets and Space (2021)

Article

Space weather benchmarks on Japanese society

We surveyed the relationship between the scale of space weather events and their occurrence rate in Japan, and we discussed the social impact of these phenomena during the Project for Solar–Terrestrial Environ...

Mamoru Ishii, Daikou Shiota, Chihiro Tao, Yusuke Ebihara… in Earth, Planets and Space (2021)

Article

Correction to: Small-Scale Dynamic Aurora

A Correction to this paper has been published: https://doi.org/10.1007/s11214-021-00821-y

Ryuho Kataoka, Christopher C. Chaston, David Knudsen… in Space Science Reviews (2021)

Article

Editorial: Topical Collection on Auroral Physics

David J. Knudsen, Joseph E. Borovsky, Tomas Karlsson… in Space Science Reviews (2021)

Article

Small-Scale Dynamic Aurora

Small-scale dynamic auroras have spatial scales of a few km or less, and temporal scales of a few seconds or less, which visualize the complex interplay among charged particles, Alfvén waves, and plasma instab...

Ryuho Kataoka, Christopher C. Chaston, David Knudsen… in Space Science Reviews (2021)

Article

Extreme geomagnetic activities: a statistical study

Statistical distributions are investigated for magnetic storms, sudden commencements (SCs), and substorms to identify the possible amplitude of the one in 100-year and 1000-year events from a limited data set ...

Ryuho Kataoka in Earth, Planets and Space (2020)

Article

Transient ionization of the mesosphere during auroral breakup: Arase satellite and ground-based conjugate observations at Syowa Station

Transient mesospheric echo in the VHF range was detected at an altitude of 65–70 km during the auroral breakup that occurred from 2220 to 2226 UT on June 30, 2017. During this event, the footprint of the Arase...

Ryuho Kataoka, Takanori Nishiyama, Yoshimasa Tanaka… in Earth, Planets and Space (2019)

Article

Visualization of rapid electron precipitation via chorus element wave–particle interactions

Chorus waves, among the most intense electromagnetic emissions in the Earth’s magnetosphere, magnetized planets, and laboratory plasmas, play an important role in the acceleration and loss of energetic electro...

Mitsunori Ozaki, Yoshizumi Miyoshi, Kazuo Shiokawa… in Nature Communications (2019)

Article

Ground-based instruments of the PWING project to investigate dynamics of the inner magnetosphere at subauroral latitudes as a part of the ERG-ground coordinated observation network

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 an...

Kazuo Shiokawa, Yasuo Katoh, Yoshiyuki Hamaguchi, Yuka Yamamoto… in Earth, Planets and Space (2017)

Article

Extreme geomagnetically induced currents

We propose an emergency alert framework for geomagnetically induced currents (GICs), based on the empirically extreme values and theoretical upper limits of the solar wind parameters and of dB/dt, the time deriva...

Ryuho Kataoka, Chigomezyo Ngwira in Progress in Earth and Planetary Science (2016)

Article

Extremely severe space weather and geomagnetically induced currents in regions with locally heterogeneous ground resistivity

Shigeru Fujita, Ryuho Kataoka, Ikuko Fujii, Antti Pulkkinen… in Earth, Planets and Space (2016)

Article

Interplanetary particle transport simulation for warning system for aviation exposure to solar energetic particles

Solar energetic particles (SEPs) are one of the extreme space weather phenomena. A huge SEP event increases the radiation dose received by aircrews, who should be warned of such events as early as possible. We...

Yûki Kubo, Ryuho Kataoka, Tatsuhiko Sato in Earth, Planets and Space (2015)

Article

Global MHD simulation of magnetospheric response of preliminary impulse to large and sudden enhancement of the solar wind dynamic pressure

A sudden increase in the dynamic pressure of solar wind generates a prominent and transient change in ground-based magnetometer records worldwide, which is called a sudden commencement (SC). The magnetic field...

Yasubumi Kubota, Ryuho Kataoka, Mitsue Den, Takashi Tanaka… in Earth, Planets and Space (2015)

Article

Estimating the solar wind conditions during an extreme geomagnetic storm: a case study of the event that occurred on March 13–14, 1989

The solar wind conditions of an extreme geomagnetic storm were examined using magnetic field observations obtained from geosynchronous satellites and the disturbance storm-time (Dst) index. During geosynchrono...

Tsutomu Nagatsuma, Ryuho Kataoka, Manabu Kunitake in Earth, Planets and Space (2015)

Article

What caused the rapid recovery of the Carrington storm?

The geomagnetic storm during the Carrington event, which occurred on 2 September 1859, displayed extremely rapid recovery. The geomagnetic field increased by approximately 650 nT/h at Bombay, India, and by >30...

Kunihiro Keika, Yusuke Ebihara, Ryuho Kataoka in Earth, Planets and Space (2015)

Article

Compound auroral micromorphology: ground-based high-speed imaging

Auroral microphysics still remains partly unexplored. Cutting-edge ground-based optical observations using scientific complementary metal-oxide semiconductor (sCMOS) cameras recently enabled us to observe the ...

Ryuho Kataoka, Yoko Fukuda, Yoshizumi Miyoshi, Hiroko Miyahara… in Earth, Planets and Space (2015)