A5025812137- Earthquake Detection and Analysis
- Ionosphere and magnetosphere dynamics
- Lightning and Electromagnetic Phenomena
- Seismic Waves and Analysis
- Solar and Space Plasma Dynamics
- earthquake and tectonic studies
- Fire effects on ecosystems
- Seismology and Earthquake Studies
- Geophysics and Sensor Technology
- Geomagnetism and Paleomagnetism Studies
- Radio Wave Propagation Studies
- Meteorological Phenomena and Simulations
- GNSS positioning and interference
- Astro and Planetary Science
- Magnetic confinement fusion research
- Atmospheric aerosols and clouds
- Soil Moisture and Remote Sensing
- Power Line Communications and Noise
- High voltage insulation and dielectric phenomena
- Advanced Fiber Optic Sensors
- Precipitation Measurement and Analysis
- Geophysics and Gravity Measurements
- Advanced Decision-Making Techniques
- Ocean Waves and Remote Sensing
- Impact of Light on Environment and Health
University of Electro-Communications
2016-2025
Osaka University
2021
Japan Aerospace Exploration Agency
2000-2021
Observatoire de Paris
2018
Laboratoire d’études spatiales et d’instrumentation en astrophysique
2018
Austrian Academy of Sciences
2018
International Superconductivity Technology Center
2010-2011
University of Sheffield
2006-2010
National Institute of Technology, Tsuyama College
2008-2009
Swedish Institute of Space Physics
2005-2006
The subionospheric VLF/LF propagation is extensively used to investigate the lower ionospheric perturbation in possible association with earthquakes. An extensive period of data over 7 yr from January 2001 December 2007 and a combination different paths around Japan are examine statistical correlation between anomaly (average nighttime amplitude, dispersion, fluctuation) earthquakes magnitude >6.0. It then found that exceeding 2 σ (standard deviation) criterion indicating presence...
Short-term (timescale of hours, days and weeks) earthquake (EQ) prediction is essential importance to mitigate EQ disasters. has so far been based on seismic measurements (i.e. mechanical observation crustal movements), but it was concluded in Japan about 10 years ago that impossible by means the method. Hence, there an increased interest a lot progress non-seismic measurement during last decade. A new approach developed where electromagnetic provide microscopic information lithosphere. The...
We present the first report of global ionospheric disturbances due to most powerful Gamma Ray Burst GRB221009A occurred on 9 October 2022. Very Low Frequency (VLF) and (LF) sub-ionospheric radio signals are used diagnose effect GRB lower ionosphere. Both daytime nighttime effects analyzed in VLF LF bands. The magnitude signal perturbations varied with propagation condition (day/night), path length, frequency signal. recovery times for VLF/LF get back their pre-GRB levels from 2–60 min. Radio...
There has been enormous progress in the field of electromagnetic phenomena associated with earthquakes (EQs) and EQ prediction during last three decades, it is recently agreed that effects do appear prior to an EQ. A few are well recognized as being statistically correlated EQs promising candidates for short-term predictors: first ionospheric perturbation not only lower ionosphere seen by subionospheric VLF (very low frequency, 3 kHz f 30 kHz)/LF (low 300 kHz) propagation but also upper F...
Gamma radiation observed in space has been associated with lightning flashes thunderstorms. These special do not appear to be the large and energetic positive ground that also produce sprites. Considerations of gamma ray attenuation air indicate such may at sufficient altitude enable their escape space. High‐altitude intracloud lightning, most prevalent tropics where tropopause is high, a necessary source.
Red sprites and elves were observed in Japan during the winter of 1998/99 Hokuriku region by group Tohoku Univ. [ Fukunishi et al., EOS, 80(46) , F217, 1999]. We analyze quantitatively results from coordinated measurement consisting ELF transients, VLF subionopheric disturbances lightning discharges associated with optical events. find clear straightforward relationship between charge transfer parent discharge calculated (f < 15 Hz) ionospheric regardless types events indicating...
We have succeeded in observing sprites for winter lightning the Hokuriku area (Japan Sea side) of Japan 2001/2002. The optical results on 3 days are compared with corresponding characteristics parent (causative) particular attention to significant differences between and more widely studied continental lightning. Despite lightning, we found nearly same sprite properties as already observed U.S. continent a difference (simpler shape sprite). Then, also discussed criteria occurrence....
The appearance of ionospheric perturbations in possible association with earthquakes (EQs) seems to be confirmed on the basis both event and statistical studies, but generation mechanism those seismo-ionospheric is not well understood, though a few hypotheses have been proposed. Two are promising candidates; one so-called chemical channel, which radon emanation results change atmospheric conductivity, then electric field, leading redistribution plasma, other excitation oscillations due some...
The width of the collisionless shock front is one key parameters. main transition layer related to nature process that balances nonlinearity and therefore leads formation itself. determines how incoming plasma particles interact with macroscopic fields within and, therefore, processes result in energy redistribution at front. Cluster Themis measurements quasi‐perpendicular part terrestrial bow are used study spatial scale magnetic ramp. It shown statistically ramp decreases increase Mach...
Abstract Global Lightning and Sprite Measurements on Japanese Experiment Module (JEM‐GLIMS) is a space mission to conduct the nadir observations of lightning discharges transient luminous events (TLEs). The main objectives this are identify horizontal distribution TLEs solve occurrence conditions determining spatial distribution. JEM‐GLIMS was successfully launched started continuous in 2012. global detected shows that most occurred over continental regions local summer hemisphere. In some...
The first X-band dual polarized phased array weather radar (DP-PAWR), which simultaneously transmits pulses of horizontal and vertical radiation, was developed installed at Saitama University, Japan, in December 2017. DP-PAWR uses mechanical electronic scanning azimuth elevation angles, respectively. It provides polarimetric precipitation measurements via 3-D volume with an update rate between 10 60 s, for a range up to 80 km. Here, we describe the initial observation results. To evaluate...
Multi-parameter observations, powerful for the study of lithosphere–atmosphere–ionosphere coupling (LAIC), have been performed a recent Tokyo earthquake (EQ) with moderate magnitude (M = 5.9) and rather larger depth (~70 km) on 7 October 2021, in hope predicting next Kanto (Tokyo) huge EQ, such as 1923 Great EQ (with greater than 7). Various possible precursors searched during two-month period 1 September to 31 based different kinds data sets: (i) ULF (ultra-low frequency) magnetic from...
The preparation phase of earthquakes (EQs) has been investigated by making full use multi-parameter and multi-layer observations EQ precursors, in order to better understand the lithosphere–atmosphere–ionosphere coupling (LAIC) process. For this purpose, we chose a specific target EQ, huge Fukushima-ken-oki on 13 February 2021 (magnitude Mj = 7.3). We initially reported precursors different physical parameters not only lithosphere, but also atmosphere ionosphere (Hayakawa et al. followed...
The purpose of this paper is to discuss the effect earthquake (EQ) preparation on changes in meteorological parameters. two physical quantities temperature (T)/relative humidity (Hum) and atmospheric chemical potential (ACP) have been investigated with use Japanese “open” data AMeDAS (Automated Meteorological Data Acquisition System), which a very dense “ground-based” network stations higher temporal spatial resolutions than satellite remote sensing open data. In order obtain clearer...
We report on the lower ionospheric anomalies observed around occurrence time of Noto Peninsula Earthquake (M7.5) January 1, 2024. A case study was conducted based continuous series data electric field amplitude acquired by VLF/LF-transmitter signal-receiving network operated University Electro-Communications in Japan. used nighttime fluctuation method to analyze and derived daily changes (1) trend (the average fluctuations) (2) dispersion variance fluctuations). As a result, decrease 4 8...
Recently, detailed spatio-temporal analysis, using X-band multi-parameter radar-derived 3D volume scan and total lightning data in Japan, have revealed the peak in-cloud (IC) occurs ~10 mins before maximum ground precipitation for individual cells of a summer thunderstorm (TS) producing torrential rain. This study investigates potential utilizing monitoring short-term prediction rain during three TS events causing heavy rainfall over Japan: an isolated TS, possessing merging two cells,...
Abstract. The results of a statistical study oxygen ion outflow using Cluster data obtained at high altitude above the polar cap is reported. Moment for both hydrogen ions (H+) and (O+) from 3 years (2001-2003) spring orbits (January to May) have been used. altitudes covered were mainly in range 5–12 RE geocentric distance. It was found that O+ significantly transversely energized altitudes, indicated by perpendicular temperatures low magnetic field values as well tendency towards higher...
Abstract. A correlation is investigated between the intensity of global electromagnetic oscillations (Schumann resonance) with planetary surface temperature. The signal was monitored at Moshiri (Japan), and temperature data were taken from meteorological observations. series covers period November 1998 to May 2002. Schumann resonance found vary coherently ground in latitude interval 45° S N: relevant cross-correlation coefficient reaches value 0.9. It slightly increases when high-latitude...
The cross‐shock electrostatic potential at the front of collision‐less shocks plays a key role in distribution energy shock front. Multipoint measurements such as those provided by Cluster II mission provide an ideal framework for study because their ability to distinguish between temporal and spacial variations We present statistical calculated around 50 crossings terrestrial bow shock. dependency normalized (with resect upstream ion kinetic energy) (Φ K ) on Alfvén Mach number is good...
This study reports on a possible very low frequency/low frequency (VLF/LF) subionospheric precursor to recent earthquake in Japan. As the epicenter of this large Japanese March 11, 2011, was located just great-circle path from one our VLF/LF network stations (Chofu) NLK US transmitter, we examined propagation characteristics mainly associated with signals as observed at three Japan (Chofu, Kasugai and Kochi). On 5 6, remarkable anomaly found Chofu, which is highly likely have been...
It is found that clear lower ionospheric perturbations appeared as a precursor to the 11 March 2011 Japan earthquake. This study based on observation of two completely different phenomena: (1) subionospheric very low frequency/low frequency propagation anomaly NLK (Seattle, USA) – Chofu path, and (2) depression magnetospheric ultra emissions observed ground (Kakioka, etc.). But, both effects are suggested be interpreted by unified phenomenon seismo-lower perturbation because they occurred...