A5026567952- Solar and Space Plasma Dynamics
- Stellar, planetary, and galactic studies
- Solar Radiation and Photovoltaics
- Geomagnetism and Paleomagnetism Studies
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Impact of Light on Environment and Health
- Spectroscopy and Quantum Chemical Studies
- Postharvest Quality and Shelf Life Management
- Food Drying and Modeling
- Geophysics and Gravity Measurements
- Astronomy and Astrophysical Research
- Phytochemicals and Antioxidant Activities
- Plant Disease Management Techniques
- Molecular spectroscopy and chirality
- Spectroscopy Techniques in Biomedical and Chemical Research
- Microencapsulation and Drying Processes
- Garlic and Onion Studies
Laboratory for Atmospheric and Space Physics
2022-2024
University of Colorado Boulder
2023-2024
National Solar Observatory
2023
AlbaNova
2019-2022
Stockholm University
2019-2022
Udaipur Solar Observatory
2017-2018
Physical Research Laboratory
2017-2018
The role of magnetic fields in the chromospheric heating problem remains greatly unconstrained. Most theoretical predictions from numerical models rely on a configuration, field strength and connectivity whose details have not been well established with observational studies. High-resolution studies plage are very scarce or non-existent general. Our aim is to study stratification vector regions. We use high-spatial resolution full-Stokes observations acquired CRISP instrument at Swedish 1-m...
It has so far proven impossible to reproduce all aspects of the solar plage chromosphere in quasi-realistic numerical models. The magnetic field configuration lower atmosphere is one few free parameters such simulations. literature only offers proxy-based estimates strength, as it difficult obtain observational constraints this region. Sufficiently sensitive spectro-polarimetric measurements require a high signal-to-noise ratio, spectral resolution, and cadence, which are at limit current...
We present high-resolution and multi-line observations of a C2-class solar flare, occurred in NOAA AR 12740 on May 6, 2019. The rise, peak decay phases the flare were recorded continuously quasi-simultaneously Ca II K line with CHROMIS instrument, 8542 Fe I 6173 \AA lines CRISP instrument at SST. chromospheric exhibit intense brightening near footpoints. At these locations, non-LTE inversion code was employed to infer temperature, magnetic field, line-of-sight (LOS) velocity microturbulent...
Abstract We analyze high-cadence vector magnetograms (135 s) and flare-ribbon observations of 37 flares from the Solar Dynamics Observatory to understand spatial temporal properties changes in photospheric magnetic field their relationship footpoints reconnected fields. Confirming previous studies, we find that largest permanent horizontal component lie near polarity inversion line, whereas vertical are less pronounced distributed throughout active region. pixels swept up by ribbons do not...
We analyze high-resolution spectropolarimetric observations of a flux-emerging region (FER) in order to understand its magnetic and kinematic structure. Our the He I 10830 Å spectral FER were recorded with GRIS at 1.5 m aperture GREGOR telescope. A Milne–Eddington-based inversion code was employed extract photospheric information Si line, whereas triplet line analyzed Hazel code, which takes into account joint action Hanle Zeeman effects. The analysis reveals complex structure near vicinity...
Abstract The present study investigated the effects of infrared and forced convective air at different power levels (300, 400, 500 W) hot temperatures (50, 57, 65°C) on thin layer drying rose petals. Infrared requires 50%–52% less time as compared with drying. initial final moisture content petals were 84% (w.b.) 4.5% respectively. Midilli–Kucuk model gives a superior fit for both methods followed by Avhad Marchetti, Page model. zero‐order, first‐order color kinetics best fitting L* , a* b*...
In 1844 Schwabe discovered that the number of sunspots increased and decreased over a period about 11 years, variation became known as sunspot cycle. Almost eighty years later, Hale described nature Sun's magnetic field, identifying it takes 22 for polarity to It was also identified latitudinal distribution resembles wings butterfly \-- showing migration in each hemisphere abruptly start at mid-latitudes (about $\pm$35$^{o}$) towards equator next years. These patterns were shown be...
Solar flares release an enormous amount of energy into the corona. A substantial fraction this is transported to lower atmosphere, which results in chromospheric heating. The mechanisms that transport solar atmosphere during a flare are still not fully understood. We aim estimate temporal evolution radiative losses chromosphere at footpoints C-class flare, order set observational constraints on electron beam parameters RADYN simulation. estimated from hydrogen, and singly ionized Ca Mg using...
Abstract Umbral dots (UDs) are transient, bright features observed in the umbral region of a sunspot. We study physical properties UDs sunspots different sizes. The aim our is to relate with large-scale sunspots. For this purpose, we analyze high-resolution G-band images 42 by Hinode /SOT, located close disk center. were corrected for instrumental stray light and restored modeled point-spread function. An automated multilevel tracking algorithm was employed identify selected images....
We present spectropolarimetric observations of an active region recorded simultaneously in the H$\alpha$ Ca II 8662 {\AA} lines. The sunspot exhibits multiple structures, including a lightbridge and where line core is emission. Correspondingly, image displays brightening emission region, with spectral profiles showing elevated cores. stratification line-of-sight magnetic field inferred through non-LTE multiline inversions weak approximation over line. strength from consistently smaller than...
Abstract We present spectropolarimetric observations of an active region recorded simultaneously in the H α and Ca ii 8662 Å lines. The sunspot exhibits multiple structures, including a light bridge where line core is emission. Correspondingly, image displays brightening emission region, with spectral profiles showing elevated cores. stratification line-of-sight magnetic field inferred through nonlocal thermodynamic equilibrium multiline inversions weak approximation (WFA) over line....
Abstract We present high-resolution observations of a C4.1-class solar flare (SOL2023-05-03T20:53) in AR 13293 from the Visible Spectro-Polarimeter (ViSP) and Broadband Imager (VBI) instruments at DKIST. The fast cadence, good resolution, high polarimetric sensitivity ViSP data provide unique opportunity to explore photospheric magnetic fields before during flare. infer field vector photosphere Fe i 6302 Å line using Milne–Eddington inversions. Combined analysis inverted VBI images reveals...
We present high-resolution observations of a C4.1-class solar flare (SOL2023-05-03T20:53) in AR 13293 from the ViSP and VBI instruments at DKIST. The fast cadence, good resolution, high polarimetric sensitivity data provide unique opportunity to explore photospheric magnetic fields before during flare. infer field vector photosphere Fe I 6302 line using Milne-Eddington inversions. Combined analysis inverted images reveals presence two oppositely-polarity pores exhibiting rotational motion...
Abstract We investigate the thermal, kinematic, and magnetic structure of small-scale heating events in an emerging flux region (EFR). use high-resolution multiline observations (including Ca ii 8542 Å, K, Fe i 6301 Å line pair) EFR located close to disk center from CRISP CHROMIS instruments at Swedish 1 m Solar Telescope. perform non-LTE inversions multiple spectral lines infer temperature, velocity, field events. Additionally, we data-driven Coronal Global Evolutionary Model simulate...
Whitepaper #335 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: space weather applications; basic research. Additional research/applications/operations pipeline; ground-based missions/projects; solar physics; […]
We investigate the thermal, kinematic and magnetic structure of small-scale heating events in an emerging flux region (EFR). use high-resolution multi-line observations (including Ca II 8542~\AA, K, Fe I 6301~\AA line pair) EFR located close to disk center from CRISP CHROMIS instruments at Swedish 1-m Solar Telescope. perform non-LTE inversions multiple spectral lines infer temperature, velocity, field events. Additionally, we data-driven Coronal Global Evolutionary Model simulate evolution...
Solar polarimetry aims at measuring the full set of Stokes vectors (I, Q, U, V) to extract magnetic field information solar atmosphere. During polarimetric observations, oblique reflections from telescope mirrors modify (crosstalk) or even produce polarization (instrumental polarization). For accurate measurements source, it is important correctly model and remove instrumental crosstalk introduced by telescope. The Multi-Application Telescope (MAST) Udaipur Observatory a Gregorian-Coude with...