153 citations · 1.1k across the 45 of their papers we have counts for
46 papers
Direct Injection of Chemically-Enhanced Plasma into a Solar Flare Arcade
Jeffrey W. Reep, Andy S. H. To
The magnetic reconnection event that drives "standard" solar flares ejects material from the reconnection site, loading mass directly onto the newly-reconnected flare arcade. To et…
Chromospheric dynamics and turbulence regulate the solar FIP effect
Andy S. H. To, J. Martin Laming, Jeffrey Reep +1
Elemental abundance variations in the solar corona, commonly characterised by First Ionisation Potential (FIP) bias, provide crucial diagnostics of chromospheric processes. The pon…
Dynamic modeling of coronal abundances during flares on M-dwarf stars
David H. Brooks, Jeffrey W. Reep, Andy S. H. To +2
Solar atmospheric elemental abundances are now known to vary both in space and time. Dynamic modeling of these changes is therefore necessary to improve the accuracy of radiative h…
A sudden fine-scale bright kernel captured by Hi-C Flare in 11 MK emission during an M1.6-class solar flare's post-maximum phase
Sanjiv K. Tiwari, Navdeep K. Panesar, Ronald L. Moore +17
On April 17, 2024, the third successful Hi-C sounding rocket flight, Hi-C Flare, recorded coronal images in Fe XXI 129 A emission from 11 MK plasma during the post-maximum phase of…
Radiative hydrodynamic simulations of FIP fractionation in solar flares
Jeffrey W. Reep, Luke Fushimi Benavitz, Andy S. H. To +5
Elemental abundances in solar flares are observed to vary both spatially and temporally, but the underlying mechanisms remain poorly understood. There is an interplay between advec…
Systematic non-thermal velocity increase preceding soft X-ray flare onset: A large-scale Hinode/EIS study
Andy S. H. To, Abigail Burden, Deborah Baker +12
Non-thermal velocities, derived from spectral line broadening, can provide crucial insights into plasma dynamics before and during solar flares. To systematically study the pre-fla…
Spatiotemporal Low FIP Abundance: A Catalyst for Coronal Condensation
Luke Fushimi Benavitz, Jeffrey W. Reep, Lucas A. Tarr +1
Radiative losses play a critical role in the cooling of plasmas. When chromospheric plasma is sufficiently heated, it can flow into coronal loops which subsequently cool down due t…
Simulation of Thermal Nonequilibrium Cycles in the Solar Wind
Roger B. Scott, Jeffrey W. Reep, Mark G. Linton +1
Thermal nonequilibrium (TNE) is a condition of the plasma in the solar corona in which the local rate of energy loss due to radiation increases to the point that it cannot be susta…
Magnetic diffusion in Solar atmosphere produces measurable electric fields
Tetsu Anan, Roberto Casini, Han Uitenbroek +13
The efficient release of magnetic energy in astrophysical plasmas, such as during solar flares, can in principle be achieved through magnetic diffusion, at a rate determined by the…
Modeling Time-Variable Elemental Abundances in Coronal Loop Simulations
Jeffrey W. Reep, John Unverferth, Will T. Barnes +1
Numerous recent X-ray observations of coronal loops in both active regions (ARs) and solar flares have shown clearly that elemental abundances vary with time. Over the course of a…
Mass Flows in Expanding Coronal Loops
Jeffrey W. Reep, Roger B. Scott, Sherry Chhabra +2
An expansion of cross-sectional area directly impacts the mass flow along a coronal loop, and significantly alters the radiative and hydrodynamic evolution of that loop as a result…
Spectroscopic Observations of Coronal Rain Formation and Evolution following an X2 Solar Flare
David H. Brooks, Jeffrey W. Reep, Ignacio Ugarte-Urra +2
A significant impediment to solving the coronal heating problem is that we currently only observe active region (AR) loops in their cooling phase. Previous studies showed that the…
Stellar Flares Are Far-Ultraviolet Luminous
Vera L. Berger, Jason T. Hinkle, Michael A. Tucker +6
We identify 182 flares on 158 stars within 100 pc of the Sun in both the near-ultraviolet (NUV: 1750-2750 Å) and far-ultraviolet (FUV: 1350-1750 Å) using high-cadence light curves…
Fundamentals of impulsive energy release in the corona
Albert Y. Shih, Lindsay Glesener, Säm Krucker +30
It is essential that there be coordinated and co-optimized observations in X-rays, gamma-rays, and EUV during the peak of solar cycle 26 (~2036) to significantly advance our unders…
Understanding the Duration of Solar and Stellar Flares at Various Wavelengths
Jeffrey W. Reep, Vladimir S. Airapetian
Recent irradiance measurements from numerous heliophysics and astrophysics missions including SDO, GOES, Kepler, TESS, Chandra, XMM-Newton, and NICER have provided critical input i…
On orbit performance of the solar flare trigger for the Hinode EUV Imaging Spectrometer
David H. Brooks, Jeffrey W. Reep, Ignacio Ugarte-Urra +1
We assess the on-orbit performance of the flare event trigger for the Hinode EUV Imaging Spectrometer. Our goal is to understand the time-delay between the occurrence of a flare, a…
Quasi-periodic pulsations in solar flares: a key diagnostic of energy release on the Sun
Andrew Inglis, Laura Hayes, Silvina Guidoni +18
Solar flares are among the most powerful and disruptive events in our solar system, however the physical mechanisms driving and transporting this energetic release are not fully un…
Delayed Development of Cool Plasmas in X-ray Flares from kappa1 Ceti
Kenji Hamaguchi, Jeffrey W. Reep, Vladimir Airapetian +3
The Neutron star Interior Composition ExploreR (NICER) X-ray observatory observed two powerful X-ray flares equivalent to superflares from the nearby young solar-like star, kappa1…
Geometric Assumptions in Hydrodynamic Modeling of Coronal and Flaring Loops
Jeffrey W. Reep, Ignacio Ugarte-Urra, Harry P. Warren +1
In coronal loop modeling, it is commonly assumed that the loops are semi-circular with a uniform cross-sectional area. However, observed loops are rarely semi-circular, and extrapo…
Solar Flare Irradiance: Observations and Physical Modeling
Jeffrey W. Reep, David E. Siskind, Harry P. Warren
We examine SDO/EVE data to better understand solar flare irradiance, and how that irradiance may vary for large events. We measure scaling laws relating GOES flare classes to irrad…
Further Evidence for Looplike Fine Structure inside "Unipolar" Active Region Plages
Y. -M. Wang, I. Ugarte-Urra, J. W. Reep
Earlier studies using extreme-ultraviolet images and line-of-sight magnetograms from the Solar Dynamics Observatory (SDO) have suggested that active region (AR) plages and strong n…
Energetics and 3-D Structure of Elementary Events in Solar Coronal Heating
G. Einaudi, R. B. Dahlburg, I. Ugarte-Urra +3
Parker (1972) first proposed that coronal heating was the necessary outcome of an energy flux caused by the tangling of coronal magnetic field lines by photospheric flows. In this…
Forecasting the Remaining Duration of an Ongoing Solar Flare
Jeffrey W. Reep, Will T. Barnes
The solar X-ray irradiance is significantly heightened during the course of a solar flare, which can cause radio blackouts due to ionization of the atoms in the ionosphere. As the…
Nanoflare Diagnostics from Magnetohydrodynamic Heating Profiles
Kalman J. Knizhnik, Will T. Barnes, Jeffrey W. Reep +1
The nanoflare paradigm of coronal heating has proven extremely promising for explaining the presence of hot, multi-million degree loops in the solar corona. In this paradigm, local…