A5079026277- Solar and Space Plasma Dynamics
- Stellar, planetary, and galactic studies
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Solar Radiation and Photovoltaics
- Cold Atom Physics and Bose-Einstein Condensates
- Geophysics and Gravity Measurements
- Advanced Frequency and Time Standards
- Atomic and Subatomic Physics Research
- Gamma-ray bursts and supernovae
- Orbital Angular Momentum in Optics
- Quantum Information and Cryptography
- Quantum optics and atomic interactions
- Atmospheric Ozone and Climate
- History and Developments in Astronomy
- Geological and Geophysical Studies
- Laser Material Processing Techniques
- Computational Physics and Python Applications
- Earthquake Detection and Analysis
- Inertial Sensor and Navigation
- Meteorological Phenomena and Simulations
- Optical Coherence Tomography Applications
- Quantum Chromodynamics and Particle Interactions
- Galaxies: Formation, Evolution, Phenomena
Lockheed Martin (United States)
2017-2024
NASA Research Park
2018-2024
Bay Area Environmental Research Institute
2017-2024
Raja Ramanna Centre for Advanced Technology
2008-2024
Learning Multi Systems (United States)
2023
Lockheed Martin (United Kingdom)
2020
Marshall Space Flight Center
2013-2019
University of Alabama in Huntsville
2017-2019
Heliophysics
2019
Max Planck Institute for Solar System Research
2011-2016
The Daniel K. Inouye Solar Telescope (DKIST) will revolutionize our ability to measure, understand and model the basic physical processes that control structure dynamics of Sun its atmosphere. first-light DKIST images, released publicly on 29 January 2020, only hint at extraordinary capabilities which accompany full commissioning five facility instruments. With this Critical Science Plan (CSP) we attempt anticipate some what those enable, providing a snapshot scientific pursuits hopes engage...
Abstract A new model describing the transport and evolution of turbulence in quiet solar corona is presented. In low plasma beta environment, transverse photospheric convective fluid motions drive predominantly quasi-2D (nonpropagating) mixed-polarity “magnetic carpet,” together with a minority slab (Alfvénic) component. We use simplified sub-Alfvénic flow velocity profile to solve equations dissipation from <?CDATA $1\hspace{0.5em}{\rm{t}}{\rm{o}}\,15\,{R}_{\odot }$?> (including Alfvén...
Abstract Hinode is Japan’s third solar mission following Hinotori (1981–1982) and Yohkoh (1991–2001): it was launched on 2006 September 22 in operation currently. carries three instruments: the Solar Optical Telescope, X-Ray EUV Imaging Spectrometer. These instruments were built under international collaboration with National Aeronautics Space Administration UK Science Technology Facilities Council, its has been contributed to by European Agency Norwegian Center. After describing satellite...
Sunspot penumbrae show high-velocity patches along the periphery. The downflow are believed to be return channels of Evershed flow. We aim investigate their structure in detail using Hinode SOT/SP observations. employ Fourier interpolation combination with spatially coupled height dependent LTE inversions Stokes profiles produce high-resolution, height-dependent maps atmospheric parameters these downflows and properties. High-speed observed over a wide range viewing angles. They have...
The sunspot penumbra comprises numerous thin, radially elongated filaments that are central for heat transport within the penumbra, but whose structure is still not clear. To investigate fine-scale of these filaments, we perform a depth-dependent inversion spectropolarimetric data very close to solar disk center obtained by Hinode (SOT/SP). We have used recently developed spatially coupled 2D scheme which allows us analyze fine individual penumbral up diffraction limit telescope. Filaments...
Abstract The third flight of the High-Resolution Coronal Imager (Hi-C 2.1) occurred on May 29, 2018; Sounding Rocket was launched from White Sands Missile Range in New Mexico. instrument has been modified its original configuration 1) to observe solar corona a passband that peaks near 172 Å, and uses new, custom-built low-noise camera. targeted Active Region 12712, captured 78 images at cadence 4.4 s (18:56:22 – 19:01:57 UT; 5 min 35 observing time). image spatial resolution varies due...
Following the success of first mission, High-Resolution Coronal Imager (Hi-C) was launched for a third time (Hi-C 2.1) on 29th May 2018 from White Sands Missile Range, NM, USA. On this occasion, 329 seconds 17.2 nm data target active region AR 12712 captured with cadence ~4s, and plate scale 0.129''/pixel. Using by Hi-C 2.1 co-aligned observations SDO/AIA 17.1 we investigate widths 49 coronal strands. We search evidence substructure within strands that is not detected AIA, further consider...
Solar campfires are fine-scale heating events, recently observed by Extreme Ultraviolet Imager (EUI), onboard Orbiter. Here we use EUI 174\AA\ images, together with EUV images from SDO/AIA, and line-of-sight magnetograms SDO/HMI to investigate the magnetic origin of 52 randomly selected in quiet solar corona. We find that (i) rooted at edges photospheric network lanes; (ii) most reside above neutral line between majority-polarity flux patch a merging minority-polarity patch, cancelation rate...
Solar tornados are dynamical, conspicuously helical magnetic structures mainly observed as a prominence activity. We investigate and propose triggering mechanism for the solar tornado in cavity by SDO/AIA on September 25, 2011. High-cadence EUV images from Ahead spacecraft of STEREO/EUVI used to correlate three flares neighbouring active-region (NOAA 11303), their waves, with dynamical developments tornado. The timings waves on-disk 195Å analyzed relation activities at limb 171Å. Each its...
Abstract Recent observations show that the buildup and triggering of minifilament eruptions drive coronal jets result from magnetic flux cancelation at neutral line between merging majority- minority-polarity patches. We investigate setting 10 on-disk small-scale UV/EUV ( jetlets , smaller than X-ray but larger chromospheric spicules) in a hole by using IRIS UV images SDO /AIA EUV line-of-sight magnetograms /HMI. observe recurring edges network lanes hole. From coaligned with AIA images, we...
Abstract The second Hi-C flight (Hi-C 2.1) provided unprecedentedly high spatial and temporal resolution (∼250 km, 4.4 s) coronal EUV images of Fe ix / x emission at 172 Å AR 12712 on 2018 May 29, during 18:56:21–19:01:56 UT. Three morphologically different types (I: dot-like; II: loop-like; III: surge/jet-like) fine-scale sudden-brightening events (tiny microflares) are seen within the ends an arch filament system in core AR. Although type Is (not reported before) resemble IRIS bombs (in...
Analysis of a time series high spatial resolution vector magnetograms the active region NOAA 10930 available from SOT/SP on-board Hinode revealed that there is mixture upward and downward currents in two foot-points an emerging flux-rope. The flux emergence rate almost same both polarities. We observe along with increase magnetic flux, net current each polarity increases initially for about three days after which it decreases. This characterized by having exactly opposite signs polarities...
We report the generation of a zero-order Bessel beam continuously variable spot size using simple optical setup. have used pair metal axicon mirrors to generate hollow dark diameter. This was subsequently focused by convex lens get size. also studied effect hollow-beam ring width on nondiffracting propagation range generated beam.
Fine-scale braiding of coronal magnetic loops by continuous footpoint motions may power heating via nanoflares, which are spontaneous fine-scale bursts internal reconnection. An initial nanoflare trigger an avalanche reconnection the braids, making a microflare or larger subflare. In contrast to this triggering subflares, we observe external subflares in braided field observed High-resolution Coronal Imager (Hi-C). We track development these using 12 s cadence images acquired SDO/AIA 1600,...
The 3D structure of sunspots has been extensively studied for the last two decades. A recent advancement Stokes inversion technique prompts us to revisit problem. We investigate global depth-dependent thermal, velocity and magnetic properties a sunspot, as well interconnection between various local properties. High quality profiles disk centered, regular sunspot acquired by SOT/SP (Hinode) are analyzed. To obtain stratification physical parameters, we use spatially coupled version SPINOR...
Abstract We examine the turbulent relaxation of solar coronal loops containing non-trivial field line braiding. Such tangling in corona has long been postulated context heating models. focus on observational signatures energy release such braided magnetic structures using MHD simulations and forward modeling tools. The aim is to answer following question: if occurs a loop flux, should we expect clearly observable signature emissions? demonstrate that presence lines does not guarantee...
We present high-resolution, high-cadence observations of six, fine-scale, on-disk jet-like events observed by the High-resolution Coronal Imager 2.1 (Hi-C 2.1) during its sounding-rocket flight. combine Hi-C images with from SDO/AIA, and IRIS, investigate each event's magnetic setting co-aligned line-of-sight magnetograms SDO/HMI. find that: (i) all six are jetlet-like (having apparent properties jetlets), (ii) rooted at edges network lanes, (iii) four stem sites flux cancelation between...
The presence of fine structures in the sunspot vector magnetic fields has been confirmed from Hinode as well other earlier observations. We studied 43 sunspots based on data sets taken ASP/DLSP, (SOT/SP) and SVM (USO). In this \emph{Letter}, (i) introduce concept signed shear angle (SSA) for establish its importance non force-free fields. (ii) find that sign global $\alpha$ (force-free parameter) is correlated with SSA photospheric chirality sunspots. (iii) Local patches opposite signs are...
Penumbral microjets (PJs) are transient narrow bright features in the chromosphere of sunspot penumbrae, first characterized by Katsukawa et al (2007) using \CaII\ H-line filter on {\it Hinode}'s Solar Optical Telescope (SOT). It was proposed that PJs form as a result reconnection between two magnetic components penumbra (spines and interspines), they could contribute to transition region (TR) coronal heating above penumbrae. We propose modified picture formation based recent results...
In this paper, we present a multi-wavelength analysis of an eruptive white-light M3.2 flare which occurred in active region NOAA 10486 on November 1, 2003. Excellent set high resolution observations made by RHESSI and TRACE provide clear evidence significant pre-flare activities for ~9 minutes the form initiation phase observed at EUV/UV wavelengths followed X-ray precursor phase. During phase, localized brightenings highly sheared core close to filament interactions among short EUV loops...
Abstract We report on the presence of numerous tiny bright dots in and around an emerging flux region (an X-ray/coronal point) observed with SolO’s EUI/HRI EUV 174 Å. These are roundish have a diameter 675 ± 300 km, lifetime 50 35 s, intensity enhancement 30% 10% above their immediate surroundings. About half remain isolated during evolution move randomly slowly (<10 km s −1 ). The other show extensions, appearing as small loop or surge/jet, propagations below 30 . Many bigger brighter...
Various theoretical and observational results have been reported regarding the presence/absence of net electric currents in sunspots. The limited spatial resolution earlier observations perhaps obscured conclusions. We analyzed 12 sunspots observed from Hinode (SOT/SP) to clarify issue. azimuthal radial components magnetic fields derived. component field is found vary sign with azimuth. also varies magnitude While latter pattern a confirmation interlocking combed structure penumbral...
A magnetic field is force-free if there no interaction between the and plasma in surrounding atmosphere i.e., electric currents are aligned with field, giving rise to zero Lorentz force. Computation of various parameters such as energy, gradient twist sunspot fields any kind extrapolations, heavily hinge on approximation photospheric fields. Thus it important inspect force-freeness The has been examined earlier by some researchers ending incoherent results. Accurate vector measurements high...