A5057699575- Lightning and Electromagnetic Phenomena
- Ionosphere and magnetosphere dynamics
- Fire effects on ecosystems
- High voltage insulation and dielectric phenomena
- Earthquake Detection and Analysis
- Meteorological Phenomena and Simulations
- Electrical Fault Detection and Protection
- Atmospheric aerosols and clouds
- Solar and Space Plasma Dynamics
- Electromagnetic Compatibility and Noise Suppression
- Plant responses to water stress
- Atmospheric Ozone and Climate
- Power Line Communications and Noise
- Seismic Waves and Analysis
- Electrostatic Discharge in Electronics
- Plant Water Relations and Carbon Dynamics
- Climate variability and models
- Astrophysics and Cosmic Phenomena
- Tropical and Extratropical Cyclones Research
- Thermal Analysis in Power Transmission
- Urban Heat Island Mitigation
- Icing and De-icing Technologies
- Magneto-Optical Properties and Applications
- Radio Wave Propagation Studies
- Pulsars and Gravitational Waves Research
University of Science and Technology of China
2018-2025
Nanjing University of Science and Technology
2025
Chinese Academy of Sciences
2015-2024
Nanjing University of Information Science and Technology
2015-2024
Wuxi Taihu Hospital
2024
Institute of Atmospheric Physics
2014-2023
Anhui Institute of Optics and Fine Mechanics
2021-2023
Hefei Institutes of Physical Science
2023
National Institute for Astrophysics
2022
University of Science and Technology Chittagong
2022
We report the observation with North Alabama Lightning Mapping Array (LMA) related to a terrestrial gamma‐ray flash (TGF) detected by RHESSI on 26 July 2008. The LMA data explicitly show TGF was produced during initial development of compact intracloud (IC) lightning between negative charge region centered at about 8.5 km above sea level (−22°C temperature level) higher positive 13 km, both confined convective core an isolated storm in close proximity footprint. After occurrence source high...
[1] We analyze the count rates of two terrestrial gamma‐ray flashes (TGFs) detected by Fermi Gamma‐ray Burst Monitor (GBM) with broadband magnetic fields (1 to 300 kHz) produced simultaneous lightning processes. The microsecond‐scale absolute time accuracy for these data, combined independent geolocations source lightning, enable this analysis higher than previously possible. In both events, fast discharge‐like processes occur within several tens microseconds generation, although not a...
[1] We report observations of two negative polarity gigantic jets sufficiently near very high-frequency (VHF) lightning mapping networks that the associated characteristics and charge transfer could be investigated. In both cases jet-producing flash began as ordinary intracloud with upper level channels attempting to exit cloud, then produced upward jet. Neither had developed ground, confirming major during occurred between cloud ionosphere. The leader progression one event was detected at...
Abstract Many details of how thunderstorms generate terrestrial gamma ray flashes (TGFs) and other forms high‐energy radiation remain uncertain, including the basic question where they are produced. We exploit association distinct low‐frequency radio emissions with generation to directly measure for first time TGF source altitude. Analysis two events reveals altitudes 11.8 ± 0.4 km 11.9 0.9 km. This places region in interior thunderstorm between main charge layers implies an intrinsic...
The temporal and spatial development of sprite‐producing lightning flashes is examined with coordinated observations over an asymmetric mesoscale convective system (MCS) on 29 June 2011 near the Oklahoma Lightning Mapping Array (LMA). Sprites produced by a total 26 were observed simultaneously video from Bennett, Colorado Hawley, Texas, enabling triangulation sprites in comparison parent (in particular, negatively charged stepped leaders) three‐dimensional space. In general, prompt within 20...
Abstract The initial breakdown stage of 10 intracloud lightning flashes that may have produced terrestrial gamma ray (TGFs) is studied with wideband E‐change, multiband B‐change, and VHF mapping data; these fit published criteria known to be associated TGFs. ( x , y z t ) locations fast pulses (IBPs) were determined E‐change data using a time‐of‐arrival (TOA) technique. Each IBP includes one or more fast‐rising subpulses. Previous research has shown typical flash initiates just above the...
Abstract While narrow bipolar events (NBEs) could be related with lightning initiation, their intrinsic physics remains in question. Here we report on optical measurements by the Atmosphere‐Space Interactions Monitor (ASIM) International Space Station (ISS) of blue flashes associated NBEs. They are observed a band centered at 337 nm, no simultaneous activity 777.4 considered strong emission line. From radio waves measured from ground, find that 7 10 single‐pulse can identified as positive...
Lightning observations in the very high frequency band and measurements of ultra low magnetic fields are analyzed to investigate charge transfer in‐cloud structure eight positive cloud‐to‐ground (+CG) strokes a mesoscale convective system. Although no altitude images were recorded, these contained large moment changes (1500–3200 C·km) capable producing nighttime sprites. Even though region storm was where flashes originated CG could occur, transferred ground mainly from stratiform region....
[1] To characterize lightning processes that produce terrestrial gamma ray flashes (TGFs), we have analyzed broadband (<1 Hz to 30 kHz) magnetic fields for TGFs detected by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) satellite in 2004–2009. The majority (96%) of 56 TGF-associated signals contain single or multiple VLF impulses superposed on a slow pulse reflects process raising considerable negative charge within 2–6 ms. Some TGF emissions also precede any appreciable...
We have analyzed very high frequency lightning mapping observations and remote magnetic field measurements to investigate connections between morphology impulse charge moment change (iCMC) of negative cloud‐to‐ground (CG) strokes with estimated peak currents. Four morphologies are identified for a total 2126 within optimum detection range the North Alabama Lightning Mapping Array, statistical iCMC distributions given each these types. Almost all (>90%) largest moments (greater than −200 C...
On 21 August 2009, the Airborne Detector for Energetic Lightning Emissions (ADELE), an array of six gamma-ray detectors, detected a brief burst gamma rays while flying aboard Gulfstream V jet near two active thunderstorm cells. The duration and spectral characteristics event are consistent with terrestrial ray flashes (TGFs) seen by instruments in low Earth orbit. A long-duration, complex +IC flash was taking place nearer cell at same time, distance ~10 km from plane. sferics that probably...
We present the very first simultaneous detection from space of a terrestrial gamma ray flash (TGF) and optical signal lightning. By fortuitous coincidence, two independent satellites passed less than 300 km thunderstorm system that produced TGF lasted 70 μ s. Together with measurements radio emissions, we have an unprecedented coverage event. find was deep in thundercloud at initial stage intracloud (IC) lightning before leader reached cloud top extended horizontally. A strong pulse by...
Abstract Using a high‐speed video camera operated at 150,000 frames per second, we have documented the upward propagation of an initial positive leader from 325 m meteorological tower in Beijing. The stepwise development was clearly revealed during its self‐sustained toward cloud base, providing first optical evidence for stepping processes leader. developed with definitive intermittent pauses and re‐establishment abrupt jump top. Obvious brush‐like corona zone emitting outward top...
Abstract By comparing the source position of pulses during initial leaders and paths subsequent dart from typical bilevel intracloud (IC) flashes, we demonstrate a new method to image detailed three‐dimensional (3‐D) structure stepping dynamics IC leaders. Using this approach, show that nearly half breakdown are not involved in main channel extension but instead originate nonpropagating branches. The primary upward significantly tilted leader channels propagated with measured mean/median 3‐D...
Abstract Terrestrial gamma ray flashes (TGFs) are brief bursts of energetic gammy‐ray photons generated during thunderstorms, which have been detected almost exclusively by satellite‐based instruments. Here we present three lines evidence includes the out simultaneously observed pairs, same occurrence contexts, and consistent estimated rate, indicate a direct relationship between subset TGFs class radio signal easily detectable ground‐based sensors. This connection indicates that these...
A fundamental question in lightning flash concerns why the discharge channel propagates a zig-zag manner and produces extensive branches. Here we report optical observation of two negative cloud-to-ground discharges with very high temporal resolution 180,000 frames per second, which shows detail dependence branching tortuous behavior on stepping process leader development. It is found that clustered space leaders formed parallel ahead tip during an individual step process. The due to...
Abstract Two cases of bidirectional leader, starting almost immediately below a decaying dart or dart‐stepped leader which terminated before reaching the ground, were identified, for first time, in rocket‐triggered lightning flashes based on high‐speed video, electric field changes, and channel base current, indicating that can be excited by decayed propagate preexisting discharge channel. The positive end moved upward along downward path, negative extended initial continuous current...
Abstract On 19 August 2012, the Imager of Sprites and Upper Atmospheric Lightning on board FORMOSAT‐2 satellite captured a sequence seven blue discharges within 1 min that emanated from parent thunderstorm over Lake Taihu in East China. The analysis lightning activity produced indicates at least six these events occurred association with negative narrow bipolar (NBEs) were concurrent discharge by less than ms, cloud‐to‐ground 6 s before each discharge, which is agreement modeling presented...
Narrow bipolar events (NBEs) are signatures in radio signals from thunderstorms observed by ground-based receivers. NBEs may occur at the onset of lightning, but discharge process is not well understood. Here, we present spectral measurements Atmosphere-Space Interactions Monitor (ASIM) on International Space Station that associated with nine negative and three positive a array We found both polarities emissions 337 nm weak or no detectable 777.4 nm, suggesting streamer breakdown. The rise...
Abstract Investigating lightning is of key significance in understanding the mechanism and mitigating hazards. We reported an experiment investigating through three‐dimensional (3D) thunder locating using a Distributed Acoustic Sensing (DAS) array Hefei, China. In this experiment, we recast 7.7 km long urban telecom optical fiber cable as 3,850 sensors DAS technique. From dense recording, manually identified 101 events during six positive cloud‐to‐ground (CG) flashes within 20 min. The...
[1] We described and applied a technique to measure the local midlatitude daytime ionospheric D region electron density profile sharpness from Earth-ionosphere waveguide mode interference pattern in spectra of radio atmospherics (or sferics for short), which are high-power, broadband, very low frequency (VLF, 3–30 kHz) signals launched by lightning discharges. VLF propagation simulations used show that upper spectral minima on several hundred kilometers long paths depend critically effective...
Sprites are structured high altitude optical emissions produced by lightning‐driven electric fields. Both strong positive and negative cloud to ground flashes (CGs) capable of initiating sprites. However, reported sprites almost exclusively +CGs. The very limited number polarity makes it difficult reveal their morphologies mechanisms. Since 2008, we have operated low light cameras at 5 locations in the United States detect transient luminous events (TLEs). At Duke University, two pairs...