A5007727883- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Astro and Planetary Science
- Planetary Science and Exploration
- Geomagnetism and Paleomagnetism Studies
- Atmospheric Ozone and Climate
- Space Exploration and Technology
- Atomic and Subatomic Physics Research
- Earthquake Detection and Analysis
- Geophysics and Gravity Measurements
- Isotope Analysis in Ecology
- Non-Destructive Testing Techniques
- Meteorological Phenomena and Simulations
- Stellar, planetary, and galactic studies
- Geophysical and Geoelectrical Methods
- Solar Radiation and Photovoltaics
- Superconducting Materials and Applications
- Advanced Mathematical Theories and Applications
- Atmospheric aerosols and clouds
- Tropical and Extratropical Cyclones Research
- High-pressure geophysics and materials
- Computational Physics and Python Applications
- Atmospheric and Environmental Gas Dynamics
- Aerospace Engineering and Energy Systems
- Magnetic and Electromagnetic Effects
Southwest Research Institute
2012-2021
University of Virginia
2016
Nebraska Wesleyan University
2016
Using measurements of the electron density n e found from passive radio wave observations by IMAGE spacecraft RPI instrument on consecutive passes through magnetosphere, we calculate long‐term (>1 day) refilling rate equatorial dn e,eq / dt L = 2 to 9. Our events did not exhibit saturation, probably because our data set include a deep solar minimum and saturation is an unusual occurrence, especially outside minimum. The median in cm −3 /day can be modeled with log 10 ( ) 2.22 − 0.006...
Abstract We report on the dynamics of low‐altitude energetic neutral atom (ENA) emissions during two substorms that occurred main phases storms: (1) a CIR‐driven storm 11 October 2008 and (2) coronal mass ejection (CME)‐driven 5 April 2010. For both these storms, we have complementary spacecraft ground‐based observations. The dual‐spacecraft Two Wide‐angle Imaging Neutral‐atom Spectrometers (TWINS) mission obtained ENA images containing (LAEs). Substorm is inferred from THEMIS all‐sky...
Stereo energetic neutral atom (ENA) images from Two Wide‐angle Imaging Neutral‐atom Spectrometers (TWINS) are analyzed using a simple line‐of‐sight (LOS) mapping approximation, for two case studies: 6 April 2010 and 29 May 2010. A previous study first reported global dawn‐dusk asymmetry favoring anisotropy on the duskside, observed by TWINS April. This paper extends refines analysis, applies it to ENA data May, find second event containing asymmetry. Ion pitch angle distributions retrieved...
Stereo energetic neutral atom (ENA) images obtained by Two Wide‐angle Imaging Neutral‐atom Spectrometers (TWINS) are analyzed to quantify the latitudinal anisotropy of ring current ENAs, and implication, system‐level pitch‐angle response during a moderate geomagnetic storm on 6 April 2010. During 15‐min interval just after midday, TWINS 1 2 were at similar local times but different latitudes, thus able simultaneously sample two pitch angles from selected locations. The observations show...
Abstract We formulate the first analytical model for energetic neutral atom (ENA) emissivity that partially corrects global viewing geometry dependence of low‐altitude emissions (LAEs) observed by Two Wide‐angle Imaging Neutral‐atom Spectrometers (TWINS). The correction requires pitch angle distribution (PAD) and geophysical location ENAs. To estimate PAD, we create an energy‐dependent model, based on a Monte Carlo simulation. account energy binning integrating PAD over each bin. finite...
Abstract This paper presents the first combined use of data from Magnetospheric Multiscale (MMS), Two Wide‐angle Imaging Neutral‐atom Spectrometers (TWINS), and Van Allen Probes (RBSP) to study 10 August 2016 magnetic dipolarization. We report correlation MMS tail observations with TWINS energetic neutral atom (ENA) images ring current (RC). analyze 15‐min, 1° 2 in 1–50 keV energy bins. To characterize high‐altitude RC we extract peak ENA flux L = 2.5 5 postmidnight sector. estimate...
Abstract This paper presents the first determination of average global and regional response ring current (RC) flux intensity versus four key solar wind (SW) interplanetary magnetic field (IMF) parameters: SW electric ( E ), IMF polarity B Z ,IMF pressure P speed V ). We analyze energetic neutral atom (ENA) images from Two Wide‐angle Imaging Neutral‐atom Spectrometers (TWINS) to measure RC response, use 5‐min downstream‐propagated data Advanced Composition Explorer (ACE) Wind driving. Our...
Abstract In this study we analyze ion differential flux from 10 events between 2008 and 2015. The fluxes are derived low‐altitude emissions (LAEs) in energetic neutral atom (ENA) images obtained by Two Wide‐angle Imaging Neutral‐atom Spectrometers (TWINS). data set comprises 119.44 hr of observations, including 4,284 per energy with 128,277 values ENA pixels near Earth's limb. Limb pixel extracted mapped to a common polar ionospheric grid associated the D s t index. Statistical analysis is...