A5008621872- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Earthquake Detection and Analysis
- Geophysics and Gravity Measurements
- GNSS positioning and interference
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Tropical and Extratropical Cyclones Research
- Planetary Science and Exploration
- Ocean Waves and Remote Sensing
- Magnetic confinement fusion research
- Spacecraft and Cryogenic Technologies
- Solar Radiation and Photovoltaics
- Meteorological Phenomena and Simulations
- Fluid Dynamics and Vibration Analysis
- Computational Physics and Python Applications
- Fluid Dynamics and Turbulent Flows
- Wind and Air Flow Studies
- Spacecraft Design and Technology
- Methane Hydrates and Related Phenomena
- Power Systems and Renewable Energy
- Text Readability and Simplification
- Natural Language Processing Techniques
- earthquake and tectonic studies
The University of Texas at Arlington
2016-2025
China University of Geosciences
2024
Tianjin University of Science and Technology
2024
Sanya University
2024
Cooperative Institute for Research in Environmental Sciences
2009-2010
NOAA Space Weather Prediction Center
2009-2010
The University of Texas at Austin
2010
High Altitude Observatory
2007-2009
NSF National Center for Atmospheric Research
2007-2009
University of Colorado Boulder
2009
Abstract Observations with a global coverage are very important for space physics research and weather monitoring. However, due to the technical limitations, it would be expensive or even impossible achieve seamless advanced observational devices. It useful fill missing data gaps create map from available data, but up until now this has been challenging. Fortunately, deep learning method, recent breakthrough in artificial intelligence, may provide an effective way solve problem by making...
A unique conjunction of the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) Challenging Minisatellite Payload (CHAMP) satellites provided simultaneous columnar neutral composition, ΣO/N 2 , thermosphere density observations, enabling a novel study thermospheric response to 7–9 November 2004 geomagnetic storm. Both mass showed profound this severe storm, but their latitudinal temporal structures differed markedly. In particular, high‐latitude depletion low‐latitude...
[1] The thermospheric response at satellite altitudes along low Earth orbit is subject to the energy deposition locally, i.e., high altitudes, and vertical wave propagation from injection lower altitudes. In this study, a general circulation model has been run investigate source of nonhydrostatic effects sensitivity wind neutral density orbits deposited Through comparing simulations with without Joule heating enhancement above 150 km altitude, impact on high-altitude thermosphere separated....
Abstract We have used all‐sky imaging to relate different types of auroral oval disturbances large‐scale traveling ionospheric (LSTIDs). selected eight nights with good and Global Positioning System total electron content coverage, including five non–storm time periods isolated initiations geomagnetic activity three storm main phase continuous activity. Periods LSTIDs generally started stopped initiation cessation found evidence that individual often show 1‐1 correspondence identifiable...
Under hydrostatic equilibrium, a typical assumption used in global thermosphere ionosphere models, the pressure gradient vertical direction is exactly balanced by gravity force. Using non‐hydrostatic Global Ionosphere Thermosphere Model (GITM), which solves complete momentum equation, primary characteristics of effects on upper atmosphere are investigated. Our results show that after sudden intense enhancement high‐latitude Joule heating, force can locally be 25% larger than force, resulting...
It is important to understand Joule heating because it can significantly change the temperature structure, atmosphere composition, and electron density hence influences satellite drag. thought that many coupled ionosphere‐thermosphere models underestimate spatial temporal variability of ionospheric electric field not totally captured within global models. Using Global Ionosphere Thermosphere Model (GITM), we explore effect variability, model resolution, vertical velocity differences between...
Simulations with the Global Ionosphere‐Thermosphere Model (GITM) show that both Poynting flux and soft electron precipitation are important in producing neutral density enhancements near 400 km altitude cusp have been observed by Challenging Minisatellite Payload (CHAMP) satellite. Imposing a of 75 mW/m 2 within model increases 34 % . The direct heating from 100 eV, produces only 5 enhancement at km. However, associated enhanced ionization F‐region leads to 24% through increased Joule...
We show evidence that solar wind density enhancements and pressure pulses can lead to intense low‐energy particle precipitation an associated, but unexpected, damping of thermospheric response. Ground‐based indices, used as proxies for energy deposition, fail capture these interactions in forecasting algorithms. Superposed epoch comparison a group poorly specified neutral storms suggests event‐chain (1) multi‐hour, pre‐storm enhancement, followed by dynamic trigger excess flux the upper...
The National Center for Atmospheric Research Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (NCAR TIE‐GCM) is employed to quantify the influence of Joule heating at different altitudes on neutral temperature and density 400 km solar minimum maximum conditions. results show that high‐altitude more efficient than low‐altitude in affecting upper thermosphere. Most deposited under 150 km, largest deposition per scale height happens about 125 independent activity. However,...
Abstract Geomagnetic storms transfer massive amounts of energy from the sun to geospace. Some that is dissipated in ionosphere as energetic particles precipitate and their atmosphere, creating aurora. We used Time History Events Macroscale Interactions during Substorms (THEMIS) mosaic all‐sky‐imagers across Canada Alaska measure amount flux deposited into via auroral precipitation 2013 March 17 storm. determined time‐dependent percent total contributed by meso‐scale (<500 km wide)...
Techniques developed in the past few years enable derivation of multi-scale regional ion convection and particle precipitation patterns from Super Dual Auroral Radar Network (SuperDARN) Time History Events Macroscale Interactions during Substorms (THEMIS) All-Sky Imager (ASI) observations, respectively. Our previous simulations driven by these geomagnetic forcing suggest that both meso-scale can intensify ionospheric thermospheric disturbances with prominent structures notable magnitudes. In...
A new quantitative empirical model of the high‐latitude forcing thermosphere, which is first with an electric field variability component consistent average field, used NCAR‐TIEGCM to investigate influence on Joule heating, neutral temperature and density. The increases heating by more than 100%, significantly improves agreement between total integrated Poynting flux, while horizontal distributions height‐integrated flux have some detailed differences in polar cap nightside regions....
An important question that is being increasingly studied across subdisciplines of Heliophysics “how do mesoscale phenomena contribute to the global response system?” This review paper focuses on this within two specific but interlinked regions in Near-Earth space: magnetotail’s transition region inner magnetosphere and ionosphere. There a concerted effort Geospace Environment Modeling (GEM) community understand degree which transport magnetotail contributes dynamics magnetic flux...
Abstract Tsunamis can generate gravity waves propagating upward through the atmosphere, inducing total electron content (TEC) disturbances in ionosphere. To capture this process, we have implemented tsunami‐generated into Global Ionosphere‐Thermosphere Model (GITM) to construct a three‐dimensional physics‐based model WP (Wave Perturbation)‐GITM. WP‐GITM takes tsunami wave properties, including height, period, wavelength, and propagation direction, as inputs time‐dependently characterizes...
Abstract As a cavity of solar radiation created by the lunar shadow moves across United States on 21 August 2017, decreases in local ionospheric and thermospheric (IT) temperature density are anticipated. The average velocity total eclipse is ~700 m/s. supersonically moving has induced bow waves gravity that observed Global Navigation Satellite System (GNSS) network. We use Ionosphere‐Thermosphere Model, global circulation model solving for nonhydrostatic equations, with high‐resolution (2°...
Recently, a vector called Rortex was proposed and successfully applied to identify the local fluid rotation with both axis strength. The first implementation relies on real Schur decomposition of velocity gradient tensor, resulting in relatively long computational time. Subsequently, mathematically equivalent eigenvector-based definition introduced an improved implementation. Unfortunately, this still tends be algorithmic description rather than explicit one involves two successive...
Abstract The tropical cyclone (TC)‐induced concentric gravity waves (CGWs) are capable of propagating upward from convective sources in the troposphere to upper atmosphere and creating traveling ionospheric disturbances (CTIDs). To examine CGWs propagation, we implement cyclone‐induced into lower boundary global ionosphere‐thermosphere model with local‐grid refinement (GITM‐R) simulate influence on ionosphere thermosphere. GITM‐R is a three‐dimensional non‐hydrostatic general circulation for...
Abstract In this study, a new high‐latitude empirical model is introduced, named for Auroral energy Spectrum and High‐Latitude Electric field variabilitY (ASHLEY). This improves specifications of soft electron precipitations electric variability that are not well represented in existing models. ASHLEY consists three components, ASHLEY‐A, ASHLEY‐E, ASHLEY‐Evar, which developed based on the precipitation bulk ion drift measurements from Defense Meteorological Satellite Program (DMSP)...
Recent attention has been given to mesoscale phenomena across geospace (∼10 s km 500 in the ionosphere or ∼0.5 R E several magnetosphere), as their contributions system global response are important yet remain uncharacterized mostly due limitations data resolution and coverage well computational power. As models improve, it becomes increasingly valuable advance understanding of role contributions—specifically, magnetosphere-ionosphere coupling. This paper describes a new method that utilizes...
This study provides first storm time observations of the westward-propagating medium-scale traveling ionospheric disturbances (MSTIDs), particularly, associated with characteristic subauroral features, storm-enhanced density (SED), polarization stream (SAPS), and enhanced thermospheric westward winds over continental US. In four recent (2017-2019) geomagnetic cases examined in this (i.e., 2018-08-25/26, 2017-09-07/08, 2017-05-27/28, 2016-02-02/03 minimum SYM-H index -206, -146, -142, -58 nT,...
In this study, the low-and mid-latitude ionospheric response to main phase of 2013 St. Patrick’s Day geomagnetic storm in American sector on dayside has been investigated using ground-based measurements and Global Ionosphere Thermosphere Model (GITM). First, it is found that observed can be well reproduced by GITM when driven electric potential electron precipitation patterns derived from Assimilative Mapping Ionospheric Electrodynamics (AMIE) technique. The AMIE-driven simulation also...