Search Publications
Can Emission Measure Distributions Derived from Extreme-ultraviolet Images Accurately Constrain High-temperature Plasma?
Winebarger, Amy R.; Athiray, P. S.
Measuring the relative amount of high-temperature, low emission measure (EM) plasma is considered to be a smoking-gun observation to constrain the frequency of plasma heating in coronal structures. Often, narrowband, extreme-ultraviolet images, such as those obtained by the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO)…
Spectroscopic Observations of Coronal Rain Formation and Evolution Following an X2 Solar Flare
Warren, Harry P.; Ugarte-Urra, Ignacio; Brooks, David H. +2 more
A significant impediment to solving the coronal heating problem is that we currently only observe active region loops in their cooling phase. Previous studies showed that the evolution of cooling loop densities and apex temperatures is insensitive to the magnitude, duration, and location of energy deposition. Still, potential clues to how energy i…
Assessing the Performance of the ADAPT and AFT Flux Transport Models Using In Situ Measurements from Multiple Satellites
Warren, Harry P.; Linton, Mark G.; Ugarte-Urra, Ignacio +7 more
The launches of Parker Solar Probe (Parker) and Solar Orbiter (SolO) are enabling a new era of solar wind studies that track the solar wind from its origin at the photosphere, through the corona, to multiple vantage points in the inner heliosphere. A key ingredient for these models is the input photospheric magnetic field map that provides the bou…
Spectroscopic Observations of the Solar Corona during the 2017 August 21 Total Solar Eclipse: Comparison of Spectral Line Widths and Doppler Shifts between Open and Closed Magnetic Structures
Landi, Enrico; Habbal, Shadia R.; Ding, Adalbert +5 more
The spectroscopic observations presented here were acquired during the 2017 August 21 total solar eclipse (TSE) with a three-channel partially multiplexed imaging spectrometer operating at extremely high orders (>50). The 4 R ⊙ extent of the slit in the north–south direction scanned the corona starting from the central meridian out t…
Energetic Electrons Accelerated and Trapped in a Magnetic Bottle above a Solar Flare Arcade
Krucker, Säm; Chen, Bin; Yu, Sijie +6 more
Where and how flares efficiently accelerate charged particles remains an unresolved question. Recent studies revealed that a "magnetic bottle" structure, which forms near the bottom of a large-scale reconnection current sheet above the flare arcade, is an excellent candidate for confining and accelerating charged particles. However, further unders…
AWSoM Magnetohydrodynamic Simulation of a Solar Active Region. II. Statistical Analysis of Alfvén Wave Dissipation and Reflection, Scaling Laws, and Energy Budget on Coronal Loops
Landi, Enrico; van der Holst, Bart; Manchester, Ward +6 more
The coronal heating problem has been a major challenge in solar physics, and a tremendous amount of effort has been made over the past several decades to solve it. In this paper, we aim at answering how the physical processes behind the Alfvén wave turbulent heating adopted in the Alfvén Wave Solar atmosphere Model (AWSoM) unfold in individual pla…
Is It Possible to Detect Coronal Mass Ejections on Solar-type Stars through Extreme-ultraviolet Spectral Observations?
Tian, Hui; Yang, Zihao; Xu, Yu +3 more
Stellar coronal mass ejections (CMEs) from host stars are an important factor that affects the habitability of exoplanets. Although their solar counterparts have been well observed for decades, it is still very difficult to find solid evidence of stellar CMEs. Using the spectral line profile asymmetry caused by the Doppler shift of erupting plasma…
Searching for Evidence of Subchromospheric Magnetic Reconnection on the Sun
Long, D. M.; van Driel-Gesztelyi, L.; Démoulin, P. +13 more
Within the coronae of stars, abundances of those elements with low first ionization potential (FIP) often differ from their photospheric values. The coronae of the Sun and solar-type stars mostly show enhancements of low-FIP elements (the FIP effect) while more active stars such as M dwarfs have coronae generally characterized by the inverse-FIP (…
Formation and Eruption of a Hot Channel Magnetic Flux Rope in a Nested Double Null Magnetic System
Yao, Surui; Shen, Yuandeng; Zhou, Chengrui +2 more
The coronal magnetic topology significantly affects the outcome of magnetic flux rope (MFR) eruptions. The recently reported nested double null magnetic system remains unclear as to how it affects MFR eruptions. Using observations from the New Vacuum Solar Telescope and the Solar Dynamics Observatory, we studied the formation and successful erupti…
An Elemental Abundance Diagnostic for Coordinated Solar Orbiter/SPICE and Hinode/EIS Observations
Matthews, Sarah A.; Warren, Harry P.; Brooks, David H. +2 more
Plasma composition measurements are a vital tool for the success of current and future solar missions, but density- and temperature-insensitive spectroscopic diagnostic ratios are sparse, and their underlying accuracy in determining the magnitude of the first ionization potential (FIP) effect in the solar atmosphere remains an open question. Here …