A5039876009- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Stellar, planetary, and galactic studies
- Solar Radiation and Photovoltaics
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Geomagnetism and Paleomagnetism Studies
- Seismic Waves and Analysis
- Meteorological Phenomena and Simulations
- earthquake and tectonic studies
- Magnetic confinement fusion research
- History and Developments in Astronomy
- Advanced Neural Network Applications
- Spacecraft Design and Technology
- Cardiovascular Disease and Adiposity
- Astrophysics and Cosmic Phenomena
- Seismic Imaging and Inversion Techniques
- CCD and CMOS Imaging Sensors
- Earthquake Detection and Analysis
- Geology and Paleoclimatology Research
- Historical Astronomy and Related Studies
- Planetary Science and Exploration
- Plasma Diagnostics and Applications
- Marine and environmental studies
- Atomic and Molecular Physics
George Mason University
2020-2025
Goddard Space Flight Center
2018-2025
University of America
2024
Catholic University of America
2024
Marshall Space Flight Center
2023
Southwest Research Institute
2023
Max Planck Institute for Solar System Research
2008-2016
Max Planck Society
2008-2010
Twisting motions of different nature are observed in several layers the solar atmosphere. Chromospheric sunspot whorls and rotation sunspots or even higher up lower corona sigmoids examples large scale twisted topology many features. Nevertheless, their occurrence at quiet photosphere has not been investigated. The present study reveals existence vortex flows located supergranular junctions Sun. We use a 1-hour 5-hour time series granulation Blue continuum G-band images from FG/SOT to derive...
<i>Context. <i/>The atmosphere of the quiet Sun is controlled by photospheric flows sweeping up concentrations mixed polarity magnetic field. Along supergranule boundaries and junctions, there a strong correlation between flux bright chromospheric transition region emission.<i>Aims. aim to investigate relationship small flare-like brightenings seen in Extreme Ultraviolet images.<i>Methods. <i/>We describe observations eruptions images taken with UltraViolet Imager (EUVI) on STEREO. The...
Solar energetic particles (SEPs) associated with shocks driven by fast coronal mass ejections (CMEs) or developed corotating interaction regions (CIRs) often extend to high energies, and are thus key elements of space weather. The PUNCH mission, set be launched in 2025, is equipped a photometric instrument that enables 3D tracking solar wind structures the interplanetary through polarized light. Tracking techniques used estimate speeds speed gradients structures, including jumps at shocks....
Abstract Global solar photospheric magnetic maps play a critical role in and heliospheric physics research. Routine magnetograph measurements of the field occur only along Sun–Earth line, leaving far side Sun unobserved. Surface flux transport (SFT) models attempt to mitigate this by modeling surface evolution field. While such have long been established community (with several releasing public full-Sun maps), none are open source. The Open-source Flux Transport (OFT) model seeks fill gap...
Context: Photospheric flows create a network of often mixed-polarity magnetic field in the quiet Sun, where small-scale eruptions and flares are commonly seen. Aims: The aim this paper is (1) to describe characteristics that lead these energy releases, (2) quantify build up due photospheric acting on field, (3) assess its contribution small-scale, short-lived X-ray Sun. Methods: We used data from SoHO Hinode spacecraft combined with tracking algorithms analyse evolution five flares. emitting...
Abstract When a coronal mass ejection departs, it leaves behind temporary void. That void is known as dimming, and contains information about the that caused it. Other physical processes can cause parts of corona to have transient dimmings, but ejections are particularly interesting because their influence in space weather. Prior work has established dimmings detectable even disk-integrated irradiance observations, i.e., Sun-as-a-star measurements. The present evaluates four years continuous...
We study horizontal supergranule-scale motions revealed by TRACE observation of the chromospheric emission, and investigate coupling between chromosphere underlying photosphere. A highly efficient feature-tracking technique called balltracking has been applied for first time to image sequences obtained (Transition Region Coronal Explorer) in passband white light three ultraviolet passbands centered at 1700 {\AA}, 1600 1550 {\AA}. The resulting velocity fields have spatially smoothed...
The wealth of observational data available has been instrumental in investigating physical features relevant to solar granulation, supergranulation and Active Regions. Meanwhile, numerical models have attempted bridge the gap between physics interior such observations. However, there are quantities that can be modelled but cannot directly measured must inferred. For example, direct measurements plasma motions at photosphere limited line-of-sight component. Methods consequently developed...
Abstract We report on observations of magnetic disturbances in active region AR12673 between 1 and 3 September 2017 seen as a disruption the moat flow several hours before onset strong flux emergence near main sunspot. The is commonly known radially oriented outflow photospheric plasma surrounding sunspots, which ends abruptly thus shapes an annular pattern around penumbra. Using highly accurate methods tracking this applied to Solar Dynamics Observatory/Helioseismic Magnetic Imager data, we...
Context: One aspect of understanding the dynamics quiet Sun is to quantify evolution flux within small-scale magnetic features. These features are routinely observed in photosphere and were given various names, such as pores, knots, patches. Aims: This work presents a new algorithm for tracking broad variety photosphere, with precision equal instrumental resolution. Methods: We have developed technique track individual from magnetograms, called "magnetic balltracking". It quantifies tracked...
The Extreme ultraviolet Imaging Spectrometer (EIS) on board Hinode is the first solar telescope to obtain wide slit spectral images that can be used for detecting Doppler flows in transition region and coronal lines Sun relate them their surrounding small scale dynamics. We select EIS covering temperature range 6x10^4 K 2x10^6 give spectrally pure of with 40 arcsec slit. In these shifts are seen as horizontal brightenings. Inside image it difficult distinguish from structures but emission...
Whitepaper #168 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research; infrastructure/workforce/other programmatic. Additional other solar physics; space-based missions/projects; research tools […]
Abstract The Wang–Sheeley–Arge (WSA) model has been in use for decades and remains a popular, economical approach to modeling the solar coronal magnetic field forecasting conditions inner heliosphere. Given its usefulness, it is unsurprising that number of WSA implementations have developed by various groups with different computational approaches. While traditionally calculated using spherical harmonic expansion field, finite-difference potential solutions can offer speed and/or accuracy...
Solar energetic particles (SEPs) associated with shocks driven by fast coronal mass ejections (CMEs) or developed corotating interaction regions (CIRs) often extend to high energies, and are thus key elements of space weather. The PUNCH mission, set be launched in 2025, is equipped photometric that enables 3D tracking solar wind structures the interplanetary through polarized light. Tracking techniques used estimate speeds speed gradients structures, including jumps at shocks. We report on a...
Abstract The Solar Dynamics Observatory (SDO) is a solar mission in an inclined geosynchronous orbit. Since commissioning, images acquired by Atmospheric Imaging Assembly (AIA) instrument on‐board the SDO have frequently displayed “spikes,” pixel regions yielding extreme number of digital counts. These are theorized to occur from energetic electron collisions with detector system. spikes regularly removed AIA Level 1.0 produce clean and reliable data. A study historical data has found over...
We address the problem of constraining mechanisms by which a massive amount energy erupts from sun at multiple scales, and how corona is heated to high temperature.These are highly dependent on magnetic field stressed.As recommended in Klimchuk et al. white paper, translational rotational motions photospheric elements important drivers coronal heating that must be accurately characterized.Yet despite an abundance observations, many uncertainties remain measuring these flows entangle twist...
Whitepaper #417 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research. Additional inner heliosphere; solar physics; space-based missions/projects.