A5101482427- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Geomagnetism and Paleomagnetism Studies
- Astronomy and Astrophysical Research
- Solar Radiation and Photovoltaics
- Spacecraft Dynamics and Control
- Astrophysics and Star Formation Studies
- Optical Polarization and Ellipsometry
- Optical Coherence Tomography Applications
- Remote Sensing in Agriculture
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
- Spectroscopy and Chemometric Analyses
- Magnetic and Electromagnetic Effects
- Astronomical Observations and Instrumentation
- Remote-Sensing Image Classification
- Gamma-ray bursts and supernovae
- Advanced Optical Sensing Technologies
- Superconducting and THz Device Technology
- Insect and Arachnid Ecology and Behavior
- Optical Imaging and Spectroscopy Techniques
- Spacecraft Design and Technology
- Spectroscopy Techniques in Biomedical and Chemical Research
Rice University
2013-2024
National Superconducting Cyclotron Laboratory
2014
Michigan State University
2014
National Research Nuclear University MEPhI
2014
Ball (France)
2014
Lockheed Martin (United States)
2002-2003
University of Colorado Boulder
1994
We report on our experimental studies of the electrostatic charging properties an Apollo 17 soil sample and two lunar simulants, Minnesota Lunar Simulant (MLS‐I) Johnson Space Center (JSC‐1). have measured their charge after exposing individual grains to a beam fast electrons with energies in range 20≤ E ≤90 eV. Our measurements indicate that secondary electron emission yield is intermediate between MLS‐1 JSC‐1, closer MLS‐1.
We revisit the "failed" filament eruption of 2002 May 27, first studied in detail by Ji et al. investigate temporal and spatial relationship between dynamics production hard X-ray emission using spatially resolved high-cadence data from TRACE RHESSI. confirm presence a source corona above prior to main activation phase identify second coronal source, not considered earlier studies, that occurs under apex during erupting when is clearly strongly kinked. argue this implies ongoing magnetic...
We utilize chromospheric observations obtained at MLSO of the 2006 December 6 Moreton wave, which exhibits two distinct fronts, and subsequent filament activation to conduct a comprehensive analysis wave-filament interaction. By determining period, amplitude, evolution oscillations in activated filament, we make certain inferences regarding physical properties both wave filament. The large-amplitude induced by passage last on order 180 minutes demonstrate complicated mixture transverse...
In the standard model of solar flares, energy deposition by a beam electrons drives strong chromospheric evaporation leading to significantly denser corona and much brighter emission across spectrum. Chromospheric was examined in great detail Fisher et al., who described distinction between two different regimes, termed explosive gentle evaporation. this work, we examine importance electron stopping depths on regimes atmospheric response. We find that with evaporation, response does not...
We investigate the kinking motion and its role in eruption of a filament/cavity system that occurred on 2002 October 31. The evolution eruptive filament consists four distinct phases. After an initial slow upward acceleration, experiences quasi-static phase exhibiting motions axis. is followed by sudden jump, coincident with onset unkinking filament. loss equilibrium initiates gradual relaxation at end which reattains similar unkinked configuration as state. structure, evident white-light...
We present the observations of contraction extreme-ultraviolet coronal loops overlying flaring region during preheating as well early impulsive phase a GOES class C8.9 flare. During relatively long, 6 minutes, phase, hard X-ray (HXR) count rates at lower energies (below 25 keV) soft fluxes increase gradually and flare emission is dominated by thermal looptop source with temperature 20-30 MK. After onset HXR bursts, spectrum composed component 17-20 MK, corresponding to emission, nonthermal...
We report multi-wavelength and multi-viewpoint observations of a solar eruptive event which involves loop-loop interactions. During C2.0 flare, motions associated with inflowing outflowing plasma provide evidence for ongoing magnetic reconnection. The flare loop top rising "concave-up" feature are connected by current-sheet-like structure (CSLS). physical properties (thickness, length, temperature, density) the CSLS evaluated. In regions adjacent to CSLS, EUV emission (characteristic...
Filaments are often observed to erupt asymmetrically, during which one leg is fixed the photosphere (referred as anchored leg) while other undertakes most of dynamic motions active eruptive process. In this paper, we present observations a group asymmetric filaments, in two types eruptions identified: whipping-like, where whips upward, and hard X-ray sources shift toward end leg; zipping-like, visible moves along neutral line like unfastening zipper filament arch rises expands. During...
We present an observational study on the impact of dynamic evolution kinking filaments production hard X-ray (HXR) emission. The investigation two kinking-filament events in this paper, occurring 2003 June 12 and 2004 November 10, respectively, combined with our earlier failed filament eruption 2002 May 27, suggests that distinct processes take place during kink evolution, leading to HXR emission different morphological connections overall magnetic configuration. first phase (Phase I) is...
We investigate the temporal and spatial variation of relative abundance He to H in a sample solar filaments by comparing cotemporal observations Hα I λ10830 obtained at MLSO. Motivated indications that cross-field diffusion neutral filament material is an important mechanism mass loss, present study offers results provide convincing test mechanisms proposed Gilbert coworkers. Specifically, when observed across entire disk passage, we find majority stable, quiescent show helium deficit upper...
A fiber-based snapshot imaging spectrometer was developed with a maximum of 31853 (~188 x 170) spatial sampling and 61 spectral channels in the 450nm-750nm range. compact, custom-fabricated fiber bundle used to sample object image at input create void spaces between rows output for dispersion. The built using multicore 6x6 block ribbons. To avoid overlap cores direction dispersion, we selected subset two alternative approaches; lenslet array photomask. calibrate >30000 samples system, rapid...
A field-ready, fiber-based high spatial sampling snapshot imaging spectrometer was developed for applications such as environmental monitoring and smart farming. The system achieves video rate frame transfer exposure times down to a few hundred microseconds in typical daylight conditions with ∼63,000 points 32 spectral channels across the 470nm 700nm wavelength range. We designed portable, ruggedized opto-mechanics allow from an airborne platform. To ensure successful data collection prior...
Traditionally, heliophysics is characterized as the study of near-Earth space environment, where plasmas and neutral gases originating from Earth, Sun, other solar system bodies interact in ways that are detectable only through in-situ or close-range (usually within ∼10 AU) remote sensing. As a result, has data environment around handful objects, particular Sun Earth. Comparatively, astrophysics an extensive array but more limited temporal, spatial, wavelength information any individual...
We consider a number of flares spanning range magnitudes over two decades in GOES soft X-ray luminosity and demonstrate an observational confirmation the saturation nonthermal hard photon flux large solar flares. Using unprecedented spectral spatial resolution RHESSI telescope, we find that integrated above 20 keV asymptotically approaches limiting value with increasing flare intensity, suggesting production for high electron-beam fluxes This result is strengthened by considering each as...
We present observations from 2007 March 2 of a partial filament eruption characterized by two distinct phases writhing motions: quasi-static, slowly evolving phase followed rapid kinking showing bifurcation the filament. The quasi-static motions are observed before there is any heating or flaring evident in EUV soft X-ray (SXR) observations. As writhe develops, sigmoid becomes sharply defined SXR. Prior to onset, appears be composed separate looplike structures, which discontinuous at...
The POLAR Investigation of the Sun (POLARIS) mission uses a combination gravity assist and solar sail propulsion to place spacecraft in 0.48 AU circular orbit around with an inclination 75 degrees respect equator. This challenging is made possible by development propulsion. first extended view high-latitude regions will enable crucial observations not from ecliptic viewpoint or Solar Orbiter. While Orbiter would give glimpse high latitude magnetic field flows probe dynamo, it does have...
We report on an eruption involving a relatively rare filament–filament interaction 2013 June 21, observed by SDO and STEREO-B. The two filaments were separated in height with "double-decker" configuration. of the lower filament began simultaneously descent upper filament, resulting convergence direct filaments. was accompanied heating surrounding plasma apparent crossing loop-like structure through filament. subsequent coalescence drove bright front ahead erupting structures. whole process...
On 1999 August 26, a coronal jet occurred at the northwest limb near sigmoid active region (AR 8668) that was target for joint observation plan (SOHO observing program 106) during third Whole Sun Month Campaign. This observed by several instruments (SOHO/CDS, SOHO/EIT, TRACE, and Mauna Loa Solar Observatory CHIP PICS) 1.64 R☉ (SOHO/UVCS). At limb, this event displayed both low- high-temperature components. Both high- low-temperature components were evident early phase (first 20 minutes) of...