A5048972245- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Earthquake Detection and Analysis
- Geomagnetism and Paleomagnetism Studies
- Atmospheric Ozone and Climate
- Lightning and Electromagnetic Phenomena
- Geophysics and Gravity Measurements
- Human Pose and Action Recognition
- Aerosol Filtration and Electrostatic Precipitation
- Multimodal Machine Learning Applications
- Video Analysis and Summarization
Wuhan University
2021-2024
Abstract This study examines field‐aligned currents (FACs) and polar electrojet (PEJ) characteristics during the extreme May 2024 geomagnetic storms across dawn, dusk, daytime, nighttime in both hemispheres. FACs PEJ intensities were up to 9 times greater than usual, with equatorward reaching −44° Magnetic Latitude. Maximum are larger at dawn dusk Northern Hemisphere but Southern Hemisphere. Dawn duskside correlate best Dst or solar wind dynamic pressure (Pd) On dayside (nightside), most...
Abstract Using 4 years of ionospheric radial current (IRC) from Swarm and ion velocity the Defense Meteorological Satellite Program, our work investigates response IRC to subauroral polarization streams (SAPS) during quiet time for first time. Both noontime (magnetic local time, MLT 11–14) inward duskside (MLT 18–19) outward get strengthened in amplitude. The ΔIRC is attributed penetration westward electric field at low‐mid latitudes. It drives poleward Hall currents equatorward field, which...
Abstract The equatorial electrojet is a strong ionospheric current along the dip equator at 110 km. It usually flows eastward and peaks noon. However, it sometimes reverses westward. Using 10 years of horizontal geomagnetic field observations from ground station, this work investigated counter (CEJ) in afternoon Indian longitudes during geomagnetically quiet time, which has substantial occurrence rate 46.7%. A total 41.7% CEJ related to westward electric substorms. intensity significant...
Using Challenging Minisatellite Payload and the Republic of China Satellite-1 observations, response ionospheric radial current (IRC) in F region to enhancement merging electric field (Em) at different magnetic local times (MLT) is investigated. Possible physical mechanisms are discussed terms neutral wind, conductivity, prompt penetration (PPEF). The disturbance IRC (ΔIRC) increases upward (downward) direction daytime (nighttime) within 3 h after Em enhancement. However, zonal...
The dynamic evolutions of the noon ionospheric Equatorial Ionization Anomaly (EIA) owing to 2022 Tonga volcanic eruption were investigated using plasma measurements from Swarm satellite, science experiment Constellation Observing Systems for Meteorology, Ionosphere, and Climate (COSMIC) mission, thermospheric wind observations Ionospheric Connection Explorer (ICON). At 14.1 universal time (UT), EIA was enhanced upward drifts, when F2-layer significantly uplifted 360 km 410 km. 15.6 UT,...
Abstract The dynamic evolution of the double tongue ionization (TOI) into a single TOI at 400 km altitude during geomagnetic storm on September 7, 2015 was studied using Defense Meteorological Satellite Program observations and Thermosphere Ionosphere Electrodynamic General Circulation model simulations. TOIs occurred in presence increased southward B z weak positive y , while northward turning duskward . In both events, plasma middle latitudes afternoon (prenoon) sector greatly enhanced due...
Abstract Based on 10 years of Defense Meteorological Satellite Program and Challenging Minisatellite Payload coordinated observations, we investigated the local time variation in response strength auroral electrojet (AEJ) with respect to sudden change solar wind inputs, including merging electric field ( E m ), substorm, interplanetary (IP) shock. The daytime (nighttime) AEJ responded several minutes (>30 min) after key enhancement. For substorms IP shocks, at all times showed an...
Abstract Using Challenging Minisatellite Payload and the Republic of China Satellite‐1 observations, response ionospheric radial current (IRC) in F region to enhancement merging electric field ( E m ) at different magnetic local times (MLT) is investigated. Possible physical mechanisms are discussed terms neutral wind, conductivity, prompt penetration (PPEF). The disturbance IRC (ΔIRC) increases upward (downward) direction daytime (nighttime) within 3 hr after enhancement. However, zonal...
Abstract The spatial distributions of single‐frequency and dual‐frequency Electromagnetic ion cyclotron (EMIC) waves in the subauroral ionosphere are investigated under varying geomagnetic activities, using high‐resolution magnetic field data from dual Swarm satellites spanning 2015 to 2017. Single‐frequency EMIC predominantly occur dawn sector, whereas exhibit peaks around both dusk. occurrence rate shows a more pronounced increase with increasing activity. As storms evolve, types shift...
Abstract Based on the high-precision vector magnetic field data of Swarm A and C satellites, we perform a statistical analysis diurnal longitudinal variations ionospheric radial current (IRC) in F layer at equator from 2014 to 2018. The observations are compared with simulations based Thermosphere–Ionosphere Electrodynamics–General Circulation Model (TIE–GCM). It is found that noon IRC radially outward, whereas dusk inward. time change inward outward direction occurred earlier June than...
In this work, local time variations of the response ionospheric F layer radial current (IRC) to southward and northward IMF turning events at low high solar activity are investigated for first using Challenging Minisatellite Payload (CHAMP) observations from 2001 2010. The strength disturbed IRC turnings does not show any preference or activity. At activity, increases in upward (downward) direction daytime (nighttime) within 1.5 h after a sudden turning. Conversely, downward (upward) zonal...
Abstract Using Challenging Minisatellite Payload (CHAMP) observations, responses of ionospheric radial current (IRC) in F‐layer to sawtooth substorms different magnetic local times are investigated. The zonal wind effect alone cannot entirely explain the variability substorm time disturbance IRC. When commence amid stable southward interplanetary field (IMF), it induces an eastward (westward) equatorial electric daytime (nighttime). This equatorward (poleward) Hall at low latitudes,...
Understanding fine-grained temporal dynamics is crucial for multimodal video comprehension and generation. Due to the lack of annotations, existing benchmarks mostly resemble static image are incompetent at evaluating models understanding. In this paper, we introduce TemporalBench, a new benchmark dedicated understanding in videos. TemporalBench consists ~10K question-answer pairs, derived from ~2K high-quality human annotations detailing clips. As result, our provides unique testbed various...
<p>The auroral electrojet plays an important role in the ionosphere-magnetosphere coupling progress. Based on ten years of DMSP and CHAMP coordinated observations, we investigate local time variations electrojets during storm periods. The results show that respond obviously to sudden change solar wind inputs (merging electric field, substorm, interplanetary shock) all time. asymmetry response strength these three types disturbances are investigated. shock faster than merging...
<p>The auroral electrojet is an important element of the polar current system and essential subject in space weather research. Based on scalar magnetic field data from CHAMP satellite, we studied influences of solar illumination dipole tilt angle (DTA) as well its seasonal variations. Furthermore, measured by satellite was compared with indices derived from the ground stations. It...