A5004264472- Lightning and Electromagnetic Phenomena
- Ionosphere and magnetosphere dynamics
- Meteorological Phenomena and Simulations
- Fire effects on ecosystems
- Atmospheric aerosols and clouds
- Solar and Space Plasma Dynamics
- Impact of Light on Environment and Health
- Precipitation Measurement and Analysis
- Tropical and Extratropical Cyclones Research
- Heart Rate Variability and Autonomic Control
- Functional Brain Connectivity Studies
- Earthquake Detection and Analysis
- High voltage insulation and dielectric phenomena
- Ocean Waves and Remote Sensing
- Soil Moisture and Remote Sensing
- Optical Imaging and Spectroscopy Techniques
- Radio Wave Propagation Studies
- Suicide and Self-Harm Studies
- Geophysics and Gravity Measurements
- GNSS positioning and interference
- Advanced Decision-Making Techniques
- Semiconductor materials and devices
- Atmospheric chemistry and aerosols
- Plant responses to water stress
- Advanced Optical Sensing Technologies
Meteorological Research Institute
2014-2022
Japan Meteorological Agency
2015-2022
Ogori Daiichi General Hospital
2022
Waseda University
2013-2021
Kindai University
2014-2020
Stanford University
1979-2012
Kyoto University
2008-2011
Tohoku University
2003-2008
NTT (United States)
1998
Previous neuroimaging studies have revealed frontal and temporal functional abnormalities in patients with major depressive disorder (MDD) a history of suicidal behavior. However, it is unknown whether multi-channel near-infrared spectroscopy (NIRS) signal changes among individuals MDD are associated suicide attempts diathesis for behavior (impulsivity, hopelessness, aggression). Therefore, we aimed to explore frontotemporal hemodynamic responses depressed using 52-channel NIRS. We recruited...
This study revisits the sprite polarity paradox, first manifest by observations that exceptional cloud‐to‐ground flashes with negative generally did not produce detectable sprites. The paradox is here resolved Transient Luminous Event (TLE) known as halo, which on account of its inferior brightness (0.3 MR versus 1.5 MR) and substantially shorter duration (1 ms 10–100 ms) in comparison sprite, readily ground‐based video cameras standard field (16.7–20 ms). Observations improved temporal...
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...
Sprite luminosities produced by winter lightning in Japan were found to be associated with simultaneous occurrences of clusters radio atmospherics as observed the VLF range, suggesting an in‐cloud discharge activity. Concurrent ELF data show transient perturbations, indicating continuous charge transfer causative lightning. These provide first evidence that activity plays important role generation mechanism sprites.
Abstract. Transient luminous events, such as red sprites, occur in the middle atmosphere electric field above thunderstorms. We here address question whether these processes may be a significant source of odd nitrogen and affect ozone or other important trace species. A well-established coupled ion-neutral chemical model has been extended for this purpose applied together with estimated rates ionisation, excitation dissociation based on spectroscopic ratios from ISUAL FORMOSAT-2. This...
Abstract This paper reports a high-speed volumetric observation of wet microburst event using X-band phased array weather radar (PAWR) in Japan. On 10 September 2014, PAWR observed the three-dimensional structure convection cell, which had vertical extent 5–6 km and horizontal dimension 2–10 km, moving toward east-northeast. At 2310 Japan standard time (JST), precipitation core with reflectivity >40 dB Z appeared at 3–5 above ground level. The then increased size intensity rapidly...
We analyze optical data of twenty sprites and three halos observed by the array photometer which is a scientific instrument ISUAL payload on FORMOSAT‐2 satellite. The altitude distribution electric field derived from ratio blue to red emission intensity assuming all emissions are due electron impact excitation nitrogen molecules. find clear transition at ∼75 km upper‐diffuse lower‐streamer region. Estimated intensities in diffuse region 0.5–0.7 E k , support theoretical expectation that...
The fundamental electrodynamical coupling processes between lightning and sprites are investigated. By combining the observed spectral data with Monte Carlo swarm experiments, reduced electric fields electron energies in sprite streamers halos estimated. obtained inside (70–97 Td an analysis error of ±5 Td) lower than conventional breakdown field, Ek ∼ 128 Td, indicating a significant reduction electrons associated while those (98–380 ±50 higher Ek, suggesting that ionization process drives...
The Imager for Sprites and Upper Atmospheric Lightning (ISUAL) on the Taiwanese FORMOSAT‐2 (formerly ROCSAT‐2) spacecraft is first global observatory of transient luminous events (TLEs). During 4 months operation a large number elves were observed. Elves are obvious with their far ultraviolet (FUV) signature that less attenuated by atmospheric O 2 at emission altitude compared to from sprites or lightning lower altitude. About half all produced shows three‐step in photometer signal: (1) An...
Although the Quasi‐electrostatic (QE) model has been considered a basic mechanism for describing sprite generation, relationship between luminosity and charge moment change (CMC) value, caused by sprites' parent lightning not examined quantitatively. CMC value represents energy of cloud‐to‐ground discharge (CG) electric field intensity above thunderstorm. We focused on data obtained in 2004, which both ISUAL board FORMOSAT‐2 satellite Tohoku ELF network were operated throughout one year....
Abstract We examine 3‐D lightning location data and radar obtained through multiple observation stations, including two X‐band phased array weather radars (PAWRs), in order to understand the relationship between thunderstorm electrification storm kinetics. In an investigated convective cell, both intracloud (IC) cloud‐to‐ground (CG) flash rates drastically change within 25 min. First, IC rate shows a steep increase with peak at 10 min −1 , then, CG peaks 7 afterward. During phase of rate,...
Abstract Global Lightning and Sprite Measurements on Japanese Experiment Module (JEM‐GLIMS) started the nadir observations of lightning discharges transient luminous events (TLEs) from International Space Station (ISS) since November 2012. In observations, JEM‐GLIMS optical instruments have to simultaneously detect incomparably intense emissions weak TLE emissions. To distinguish TLEs, especially sprite events, combined data analytical methods are adopted: (1) a subtraction wideband camera...
In order to elucidate the electrodynamic coupling process between sprites and their causative cloud‐to‐ground lightning discharges, we investigated 38 columniform sprite events observed in wintertime campaigns Japan. By analyzing data of images, transient Schumann resonance waveforms JLDN/LPATS detection network systems, found that number columns each event was proportional peak current intensity positive discharges (+CGs) while average vertical length charge moment +CGs. Based on these...
From July 2004 to June 2007, the FORMOSAT‐2/ISUAL spectrophotometer and Duke magnetometer observed clear optical radio signatures of 12 sprite‐producing lightning events. In 10 these, 777.4‐nm luminosity normalized a distance 3000 km was almost linearly correlated with current moment scaling factor ∼0.82 MR/kAkm. This finding provides possible new way remotely measure moment, which is critical for understanding production sprites, through satellite‐based measurements. The remaining 2 events...
Abstract No direct observational evidence of sprite‐produced active radicals has been presented owing to the difficulty observing a small event area in nighttime mesosphere, whereas sprite chemical models have indicated that discharge locally affects atmospheric composition. We present first HO production above sprite‐producing thunderstorms from coincidence temporal‐spatial observations spectra, events, and by two space instruments, submillimeter‐wave limb spectrometer ultraviolet/visible...
Abstract Phased array radars (PARs) are a promising observing technology, at the cusp of being available to broader meteorological community. PARs offer near-instantaneous sampling atmosphere with flexible beam forming, multifunctionality, and low operational maintenance costs without mechanical inertia limitations. These PAR features transformative compared those offered by our current reflector-based radars. The integration into research has potential revolutionize way we observe...
We have performed, for the first time, measurements of electronic structure Si-SiO2 interface with electron energy loss spectroscopy (ELS) in connection argon-ion sputtering. measured depth profiles both 5.1- and 7.2-eV ELS peaks, which been previously observed Si surface oxygen adsorbed SiO2 defects present. found that intensities these especially 5.1-eV peak, show a maximum at interface. This suggests peaks come from special bonding configurations characteristic connective layer between
SIPOS (semi‐insulating polycrystalline silicon) films with 40 atomic percent oxygen have been studied Auger electron spectroscopy (AES) and photoelectron (PES). The comparison of the Si LVV spectra 2p lines suggests that as‐grown film contains large amounts as well . Annealing at 1100°C causes crystal growth change towards An additional peak 83 eV is found in spectra, which has reported to exist interface, can be attributed
Schizophrenia (SZ) and bipolar I disorder (BD-I) share genetic risk factors cognitive impairments, but these conditions may exhibit differences in cortical functioning associated with inhibitory control. We measured hemodynamic responses during a stop-signal task using near-infrared spectroscopy (NIRS) 20 patients SZ, 21 BD-I 18 healthy controls (HCs). used reaction time (SSRT) to estimate behavioural inhibition. Compared HCs, either SZ or exhibited significantly reduced activation the...