Tootfinder

Langmuir Wave Excitation in Solar-wind Magnetic Holes
Jingting Liu, Daniel Verscharen, Jesse Coburn, Georgios Nicolaou, Xiangyu Wu, Wence Jiang, Oreste Pezzi, Francesco Pucci, Matteo Zuin, Christopher J. Owen, Hamish Reid
https://arxiv.org/abs/2507.02042

Langmuir Wave Excitation in Solar-wind Magnetic Holes
Magnetic holes are structures commonly observed in various space plasma environments throughout the solar system, including the solar wind. These structures are characterized by a localized decrease in magnetic field strength, coincident with an increase in plasma density. Previous observational studies in the solar wind link the presence of Langmuir waves to magnetic holes, suggesting a strong correlation between these phenomena. We develop a model based on magnetic-moment conservation and its…

Inverse Velocity Dispersion of Solar Energetic Protons Observed by Solar Orbiter and Its Shock Acceleration Explanation
Yuncong Li, Jingnan Guo, Daniel Pacheco, Yuming Wang, Manuela Temmer, Zheyi Ding, Robert F. Wimmer-Schweingruber
https://arxiv.org/abs/2507.00954

Inverse Velocity Dispersion of Solar Energetic Protons Observed by Solar Orbiter and Its Shock Acceleration Explanation
The particle acceleration and transport process during solar eruptions is one of the critical and long-standing problems in space plasma physics. Through decades of research, it is well accepted that particles with higher energies released during a solar eruption arrive at observers earlier than the particles with lower energies, forming a well-known structure in the dynamic energy spectrum called particle velocity dispersion (VD), as frequently observed by space missions. However, this picture…

Probing the Turbulent Corona and Heliosphere Using Radio Spectral Imaging Observation during the Solar Conjunction of Crab Nebula
Peijin Zhang, Surajit Mondal, Bin Chen, Sijie Yu, Dale Gary, Marin M. Anderson, Judd D. Bowman, Ruby Byrne, Morgan Catha, Xingyao Chen, Sherry Chhabra, Larry D'Addario, Ivey Davis, Jayce Dowell, Katherine Elder, Gregg Hallinan, Charlie Harnach, Greg Hellbourg, Jack Hickish, Rick Hobbs, David Hodge, Mark Hodges, Yuping Huang, Andrea Isella, Daniel C. Jaco…

Probing the Turbulent Corona and Heliosphere Using Radio Spectral Imaging Observation during the Solar Conjunction of Crab Nebula
Measuring plasma parameters in the upper solar corona and inner heliosphere is challenging because of the region's weakly emissive nature and inaccessibility for most in situ observations. Radio imaging of broadened and distorted background astronomical radio sources during solar conjunction can provide unique constraints for the coronal material along the line of sight. In this study, we present radio spectral imaging observations of the Crab Nebula (Tau A) from June 9 to June 22, 2024 when it…

Solar Cycle Variations in Meridional Flows and Rotational Shear within the Sun's Near-surface Shear Layer: #solar rotation: https://www.nature.com/articles/d44151-025-00101-6 - scientists uncover how deep plasma flows reshape the Sun’s rotation and hint at mysteries below its surface.

Ensemble Modeling of the Solar Wind Flow with Boundary Conditions Governed by Synchronic Photospheric Magnetograms. I. Multi-point Validation in the Inner Heliosphere
Dinesha V. Hegde (Department of Space Science, The University of Alabama in Huntsville, Huntsville, USA, Center for Space Plasma and Aeronomic Research, The University of Alabama in Huntsville, Huntsville, USA), Tae K. Kim (Center for Space Plasma and Aeronomic Research, The University of Alabama in Huntsville, Huntsville…

Ensemble Modeling of the Solar Wind Flow with Boundary Conditions Governed by Synchronic Photospheric Magnetograms. I. Multi-point Validation in the Inner Heliosphere
The solar wind (SW) is a vital component of space weather, providing a background for solar transients such as coronal mass ejections, stream interaction regions, and energetic particles propagating toward Earth. Accurate prediction of space weather events requires a precise description and thorough understanding of physical processes occurring in the ambient SW plasma. Ensemble simulations of the three-dimensional SW flow are performed using an empirically-driven magnetohydrodynamic heliospher…

Polarization ratios of turbulent Langmuir/$\mathcal{Z}$-mode waves generated by electron beams in magnetized solar wind plasmas
Francisco Javier Polanco-Rodr\'iguez, Catherine Krafft, Philippe Savoini
https://arxiv.org/abs/2506.18429

Polarization ratios of turbulent Langmuir/$\mathcal{Z}$-mode waves generated by electron beams in magnetized solar wind plasmas
The polarization ratios $F=|E_\perp|^2/|E|^2$ of beam-generated turbulent Langmuir/$\mathcal{Z}$-mode ($\mathcal{LZ}$) waves and electromagnetic emissions radiated at plasma frequency $ω_p$ by such sources are studied in weakly magnetized and randomly inhomogeneous plasmas owing to large-scale and long-term 2D/3V Particle-In-Cell simulations with parameters relevant to type III solar radio bursts. Statistical studies using waveforms recorded by virtual satellites are perfor…

Magnetic Reconnection in a Compact Magnetic Dome - Chromospheric Emissions and High-velocity Plasma Flows: #Solar Explosion Reveals Big Clues About Magnetic Reconnection: https://nso.edu/blog/small-scale-solar-explosion-reveals-big-clues-about-magnetic-reconnection/

Insights into Chromospheric Large-Scale Flows using Nobeyama 17 GHz Radio Observations I. The Differential Rotation Profile
Srinjana Routh, Anshu Kumari, Vaibhav Pant, Jaydeep Kandekar, Dipankar Banerjee, Mohd. Saleem Khan, Dibya Kirti Mishra
https://arxiv.org/abs/2507.02630

Insights into Chromospheric Large-Scale Flows using Nobeyama 17 GHz Radio Observations I. The Differential Rotation Profile
Although the differential rotation rate on the solar surface has long been studied using optical and extreme ultraviolet (EUV) observations, associating these measurements to specific atmospheric heights remains challenging due to the temperature-dependent emission of tracers observed in EUV wavelengths. Radio observations, being primarily influenced by coherent plasma processes and/or thermal bremsstrahlung, offer a more height-stable diagnostic and thus provide an independent means to test an…

Plasma refilling of the lunar wake: plasma-vacuum interactions, electrostatic shocks, and electromagnetic instabilities
Xin An, Vassilis Angelopoulos, Terry Z Liu, Anton Artemyev, Andrew R. Poppe, Donglai Ma
https://arxiv.org/abs/2505.12497

Plasma refilling of the lunar wake: plasma-vacuum interactions, electrostatic shocks, and electromagnetic instabilities
A plasma void forms downstream of the Moon when the solar wind impacts the lunar surface. This void gradually refills as the solar wind passes by, forming the lunar wake. We investigate this refilling process using a fully kinetic particle-in-cell (PIC) simulation. The early stage of refilling follows plasma-vacuum interaction theory, characterized by exponential decay of plasma density into the wake, along with ion acceleration and cooling in the expansion direction. Our PIC simulation confirm…

Galactic echoes
Rimpei Chiba, Jupiter Ding, Chris Hamilton, Matthew W. Kunz, Scott Tremaine
https://arxiv.org/abs/2506.16512 https://…

Galactic echoes
Gaia has revealed a variety of substructures in the phase space of stars in the Solar neighborhood, including the vertical `Snail' in $(z,v_z)$ space. Such substructures are often interpreted as the incompletely phase-mixed response of the disc stars to a single perturbation, such as an impulsive encounter with a satellite galaxy. In this paper we consider the possibility that such structures contain manifestations of phase space echoes. First established in plasma physics in the 1960s, echoes …

The effect of plasma-$\beta$ on the heating mechanisms during magnetic reconnection in partially ionized low solar atmosphere
Abdullah Zafar, Lei Ni, Kaifeng Kang, Guanchong Cheng, Jing Ye, Jun Lin, Ahmad Ali, Nadia Imtiaz
https://arxiv.org/abs/2506.17579

The effect of plasma-$β$ on the heating mechanisms during magnetic reconnection in partially ionized low solar atmosphere
We performed numerical simulations of magnetic reconnection with different strength of magnetic fields from the solar photosphere to the upper chromosphere. The main emphasis is to identify dominant mechanisms for heating plasmas in the reconnection region under different plasma-$β$ conditions in the partially ionized low solar atmosphere. The numerical results show that more plasmoids are generated in a lower $β$ reconnection event. The frequent coalescence of these plasmoids leads to a sign…

Solar-cycle Variability of Composite Geometry in the Solar Wind Turbulence
Zhan Fa, H. -Q. He
https://arxiv.org/abs/2505.12870 https://

Solar-cycle Variability of Composite Geometry in the Solar Wind Turbulence
The composite geometry and spectral anisotropy of the solar wind turbulence are very important topics in the investigations of solar wind. In this work, we use the magnetic field and plasma data from Wind spacecraft measured during 1995 January to 2023 December, which covers more than two solar cycles, to systematically investigate these subjects in the context of solar-cycle variability. The so-called spectrum ratio test and spectrum anisotropy test are employed to determine the three-dimensio…

Steady-State Heating of Diffuse Coronal Plasma in a Solar Active Region
Gregory D. Fleishman, Alexey A. Kuznetsov, Gelu M. Nita
https://arxiv.org/abs/2506.18723

Steady-State Heating of Diffuse Coronal Plasma in a Solar Active Region
Solar corona is much hotter than lower layers of the solar atmosphere-photosphere and chromosphere. The coronal temperature is up to 1MK in quiet sun areas, while up to several MK in active regions, which implies a key role of magnetic field in coronal heating. This means that understanding coronal heating requires reliable modeling of the underlying three-dimensional (3D) magnetic structure of an active region validated by observations. Here we employ synergy between 3D modeling, optically thi…

Electromagnetic radiation by turbulent, magnetized and randomly inhomogeneous solar radio sources generated by electron beams
Catherine Krafft, Alexandr Volokitin, Francisco Javier Polanco-Rodr\'iguez, Philippe Savoini
https://arxiv.org/abs/2506.16816

Electromagnetic radiation by turbulent, magnetized and randomly inhomogeneous solar radio sources generated by electron beams
During Type III solar radio bursts, electromagnetic waves are radiated at plasma frequency $ω_p$ and its harmonics by electrostatic wave turbulence generated by electron beams ejected by Sun in randomly inhomogeneous solar wind and coronal plasmas. These emissions, detected since decades by spacecraft and radiotelescopes, are split by the plasma magnetic field into three modes $\mathcal{X}$, $\mathcal{O}$ and $\mathcal{Z}$ of different dispersion, polarization and radiation properties. This wo…

The effect of plasma expansion on the dispersion properties of MHD waves
Sebasti\'an Saldivia, Felipe A. Asenjo, Pablo S. Moya
https://arxiv.org/abs/2506.08248

The effect of plasma expansion on the dispersion properties of MHD waves
In this work, we employ the set of ideal expanding magnetohydrodynamic (MHD) equations within the Expanding Box Model (EBM) framework to theoretically characterize the effects of radial solar wind expansion on its characteristic linear MHD waves. Through the analytical derivation of dispersion relations by a first-order expansion of the MHD-EBM equations, we explore the changes in wave propagation across a range of heliocentric distances on the linear magnetohydrodynamic modes: the Alfvén mode…

This https://arxiv.org/abs/2505.09869 has been replaced.
initial toot: https://mastoxiv.page/@a…

How does the limited resolution of space plasma analyzers affect the accuracy of space plasma measurements?
We investigate the systematic errors in measured plasma velocity distribution functions and their corresponding velocity moments, arising from the limited energy and angular resolution of top-hat electrostatic analyzers. For this purpose, we develop a forward model of a concept analyzer that simulates observations of typical solar wind proton plasma particles with their velocities following a Maxwell distribution function. We then review the standard conversion of the observations to physical p…

The Quasi-Radial Field-line Tracing (QRaFT): an Adaptive Segmentation of the Open-Flux Solar Corona
Vadim M. Uritsky, Christopher E. Rura, Cooper Downs, Shaela I. Jones, Charles Nickolos Arge, Nathalia Alzate
https://arxiv.org/abs/2506.14894

The Quasi-Radial Field-line Tracing (QRaFT): an Adaptive Segmentation of the Open-Flux Solar Corona
Optical observations of solar corona provide key information on its magnetic geometry. The large-scale open field of the corona plays an important role in shaping the ambient solar wind and constraining the propagation dynamics of the embedded structures, such as interplanetary coronal mass ejections. Rigorous analysis of the open-flux coronal regions based on coronagraph images can be quite challenging because of the depleted plasma density resulting in low signal-to-noise ratios. In this pape…

This https://arxiv.org/abs/2501.09651 has been replaced.
initial toot: https://mastoxiv.page/@a…

Electron scale magnetic holes generation driven by Whistler-to-Bernstein mode conversion in fully kinetic plasma turbulence
Magnetic holes (MHs) are coherent structures characterized by a strong and localized magnetic field amplitude dip, commonly observed in the solar wind and planetary magnetosheaths. These structures come in different sizes, from magnetohydrodynamic to kinetic scales. Magnetospheric Multiscale (MMS) observations have revealed electron scale MHs to be ubiquitous in the turbulent Earth's magnetosheath, potentially playing an important role in the energy cascade and dissipation. Despite abundant obs…

Counter-Streaming Velocities in a Quiescent Filament
Garima Karki, Brigitte Schmieder, Pascal Demoulin, Pooja Devi, Ramesh Chandra, Reetika Joshi
https://arxiv.org/abs/2506.18115 …

Counter-Streaming Velocities in a Quiescent Filament
Filaments/prominences are cold plasma (~ 10000 K) embedded in the solar corona, two orders of magnitude hotter. Filament plasma is structured by the magnetic field in thin elongated threads. Counter-streaming flows have been observed. The aim of this paper is to characterize these flows. For that, we use high spatial resolution observations of spectral data obtained with THEMIS in H-alpha and with IRIS in Mg II k lines on 29 September 2023. We best detect counter-streaming flows in both the blu…

Driven phase-mixed Alfv\'en waves in a partially ionized solar plasma
Max McMurdo, Istvan Ballai, Gary Verth, Viktor Fedun
https://arxiv.org/abs/2506.08732

Driven phase-mixed Alfvén waves in a partially ionized solar plasma
Phase mixing has long been understood to be a viable mechanism for expediting the dissipation of Alfvén wave energy resulting in the subsequent heating of the solar atmosphere. To fulfil the conditions necessary for phase mixing to occur, we consider the cross-field gradient in the Alfvén speed as a free parameter in our model. Using a single-fluid description of a partially ionized chromospheric plasma, we explore the efficiency of damping of shear Alfvén waves subject to phase mixing when …

Energy budget in the 2017-09-07 "cold" solar flare
Gregory D. Fleishman, Galina G. Motorina, Sijie Yu, Gelu M. Nita
https://arxiv.org/abs/2506.15501

Energy budget in the 2017-09-07 "cold" solar flare
A subclass of early impulsive solar flares, cold flares, was proposed to represent a clean case, where the release of the free magnetic energy (almost) entirely goes to acceleration of the nonthermal electrons, while the observed thermal response is entirely driven by the nonthermal energy deposition to the ambient plasma. This paper studies one more example of a cold flare, which was observed by a unique combination of instruments. In particular, this is the first cold flare observed with the …

Investigation of Martian UV Dayglow Emissions in the Southern Hemisphere during Solar Quiet-time Conditions: Insights from Multi-year MAVEN/IUVS Observations
Aadarsh Raj Sharma, Lot Ram, Sumanta Sarkhel
https://arxiv.org/abs/2505.13977

Investigation of Martian UV Dayglow Emissions in the Southern Hemisphere during Solar Quiet-time Conditions: Insights from Multi-year MAVEN/IUVS Observations
The southern hemisphere of Mars possesses concentrated region of strong crustal magnetic fields (CMF), which generate localized magnetic anomalies that can influence atmospheric dynamics and energy deposition in the Martian thermospheric-ionospheric system. Although their effects on the atmosphere (>200 km) in the southern hemisphere are well documented, however their role in modulating the behavior of atmospheric plasma and neutrals below 200 km are poorly understood. The atmosphere at these a…

Mathematical Modeling of Kelvin-Helmholtz Instability at Tangential Discontinuities in Partially Ionized Plasma: Application to Heliopause Dynamics
A. V. Titova, S. D. Korolkov, V. V. Izmodenov
https://arxiv.org/abs/2506.14343

Mathematical Modeling of Kelvin-Helmholtz Instability at Tangential Discontinuities in Partially Ionized Plasma: Application to Heliopause Dynamics
The stability of the heliopause, the tangential discontinuity separating the solar wind from the interstellar medium, is influenced by various processes, including the Kelvin-Helmholtz instability. This study investigates the role of charge exchange collisions between protons and hydrogen (H) atoms in reduction of the Kelvin-Helmholtz growth rate at the heliopause. Using a two-dimensional gasdynamic model with the inclusion of H atoms, we perform numerical simulations of the plasma flow near th…

Dynamics of Subsurface Flows in Solar Active Regions During the May 2024 Storm
B Lekshmi, Sushanta Tripathy, Kiran Jain, Alexei Pevtsov
https://arxiv.org/abs/2506.08141

Dynamics of Subsurface Flows in Solar Active Regions During the May 2024 Storm
In May 2024, the Sun exhibited intense magnetic activity, marked by numerous high-intensity flares resulting from the interaction and merging of NOAA ARs 13664 and 13668 in the southern hemisphere and AR 13663 in the northern hemisphere. Notably, AR 13664 displayed an extended lifetime, remaining visible after a full solar rotation and continuing to produce significant flaring activity. In this study, we investigate the evolution of sub-photospheric plasma flows associated with these ARs during…

Systematic non-thermal velocity increase preceding soft X-ray flare onset
Andy S. H. To, Abigail Burden, Deborah Baker, Henrik Eklund, David H. Brooks, Laura A. Hayes, Juan Mart\'inez-Sykora, Paola Testa, Jeffrey Reep, Miho Janvier, Shinsuke Imada, Julio Hernandez Camero, David M. Long, Teodora Mihailescu, Micah J. Weberg
https://

Systematic non-thermal velocity increase preceding soft X-ray flare onset
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-flare phase, we constructed a Hinode/Extreme-ultraviolet Imaging Spectrometer (EIS) flare catalog of 1,449 flares from 2011-2024. This enabled a large-scale analysis of flare loop footpoint non-thermal velocity evolution across different flare magnitudes (C, M, X-classes). Analyzing Fe VIII - Fe XXIV emission lines forme…