scholarly journals The Atmospheric Response to High Nonthermal Electron Beam Fluxes in Solar Flares. I. Modeling the Brightest NUV Footpoints in the X1 Solar Flare of 2014 March 29

2017 ◽  
Vol 836 (1) ◽  
pp. 12 ◽  
Author(s):  
Adam F. Kowalski ◽  
Joel C. Allred ◽  
Adrian Daw ◽  
Gianna Cauzzi ◽  
Mats Carlsson
Keyword(s):  
Electron Beam ◽  
Solar Flare ◽  
Solar Flares ◽  
Nonthermal Electron ◽  
Atmospheric Response

scholarly journals Response of chromospheric lines to different periodic non-thermal electron beams

2015 ◽  
Vol 11 (S320) ◽  
pp. 239-242
Author(s):  
Jianxia Cheng ◽  
Mingde Ding
Keyword(s):  
Electron Beam ◽  
Solar Flares ◽  
Local Thermodynamic Equilibrium ◽  
Response Times ◽  
Electron Beams ◽  
Lower Atmosphere ◽  
Mass Motion ◽  
Thermal Electron ◽  
Hydrodynamic Simulations ◽  
Beam Injection

AbstractSolar flares produce radiations in very broad wavelengths. Spectra can supply us abundant information about the local plasma, such as temperature, density, mass motion and so on. Strong chromospheric lines, like the most studied Hα and Ca II 8542 Å lines are formed under conditions of departures from local thermodynamic equilibrium in the lower atmosphere subject to flare heating. Understanding how these lines are formed is very useful for us to correctly interpret the observations. In this paper, we try to figure out the response of chromospheric lines heated by different periodic non-thermal electron beams. Our results are based on radiative hydrodynamic simulations. We vary the periods of electron beam injection from 1.25 s to 20 s. We compare the response times to different heating parameters. Possible explanations are discussed.

scholarly journals On the Possibility of Local Magnetic Field Intensification in Evaporating Chromospheric Solar Flare Plasma

1989 ◽  
Vol 104 (2) ◽  
pp. 341-344
Author(s):  
V. N. Dermendjiev ◽  
G. T. Buyukliev ◽  
I. Ph. Panayotova
Keyword(s):  
Magnetic Field ◽  
Solar Flare ◽  
Solar Flares ◽  
Local Magnetic Field ◽  
Plume Structure ◽  
The Subject ◽  
Convective Plume ◽  
Flare Plasma ◽  
Initial Magnetic Field ◽  
Moving Vortex

The investigations of plasma motions at the initial phases of solar flares (Antonucci and Dennis, 1983; Doschek, 1983; Watanabe, 1987) suggest evaporation from the chromospheric flaring area. According to de Jager (1983) when seen at the limb the evaporated plasma will look like a “convective plume” and it can be seen separated from heated footpoint areas.The subject of this work is the study of the possibility of forming hydrodynamic structures o-f thermal and starting plume's kind at the time of evaporation of the upper chromosphere in a flaring area. Also the possibility of increasing an initial magnetic field by a periodically moving vortex in a plume structure is investigated.

scholarly journals Preface

1991 ◽  
Vol 336 (1643) ◽  
pp. 323-323
Keyword(s):  
Solar Flare ◽  
Energy Release ◽  
Gamma Rays ◽  
Solar Flares ◽  
Solar Maximum ◽  
Interplanetary Space ◽  
Release Site ◽  
Solar Maximum Mission ◽  
New Information ◽  
Three Space

During the period of the 1980 solar maximum three space missions (P78-1, Solar Maximum Mission and Hinotori ) carried out extensive studies of solar flares. In their different ways all of these missions contributed significant new information to our understanding of the solar flare phenomenon. In this volume the contribution made by these three spacecraft to the study of the energy release and the related creation of high-tem perature plasma, the transport of energy from the primary release site, the production of gamma-rays at energies up to 10 MeV and the ejection of solar matter into interplanetary space are reviewed.

Multiple-wavelength analysis of energy release during a solar flare - Thermal and nonthermal electron populations

1990 ◽  
Vol 357 ◽  
pp. 662 ◽  
Author(s):  
Robert F. Willson ◽  
Kenneth R. Lang ◽  
Karl-Ludwig Klein ◽  
Alain Kerdraon ◽  
Gerard Trottet
Keyword(s):  
Solar Flare ◽  
Energy Release ◽  
Nonthermal Electron ◽  
Multiple Wavelength

Testing the Impulsiveness of Solar Flare Heating through Analysis of Dynamic Atmospheric Response

1996 ◽  
Vol 459 ◽  
pp. 804 ◽  
Author(s):  
E. K. Newton ◽  
A. G. Emslie ◽  
J. T. Mariska
Keyword(s):  
Solar Flare ◽  
Atmospheric Response

scholarly journals Electron Beam as Origin of White-Light Solar Flares

1989 ◽  
Vol 104 (1) ◽  
pp. 19-30
Author(s):  
J. Aboudarham ◽  
J. C. Henoux
Keyword(s):  
Electron Beam ◽  
White Light ◽  
Solar Flares ◽  
Light Emission ◽  
Continuum Emission ◽  
Continuum Radiation ◽  
Photospheric Level ◽  
Hydrogen Ionization ◽  
Semi Empirical ◽  
Flare Model

AbstractWe study the effect of chromospheric bombardment by an electron beam during solar flares. Using a semi-empirical flare model, we investigate energy balance at temperature minimum level and in the upper photosphere. We show that non-thermal hydrogen ionization (i.e., due to the electrons of the beam) leads to an increase of chromospheric hydrogen continuum emission, H− population, and absorption of photo-spheric and chromospheric continuum radiation. So, the upper photosphere is radiatively heated by chromospheric continuum radiation produced by the beam. The effect of hydrogen ionization is an enhanced white-light emission both at chromospheric and photospheric level, due to Paschen and H− continua emission, respectively. We then obtain white-light contrasts compatible with observations, obviously showing the link between white-light flares and atmospheric bombardment by electron beams.

Atomic physics calculations relevant to solar flare spectra

1991 ◽  
Vol 336 (1643) ◽  
pp. 471-484 ◽  
Keyword(s):  
Solar Flare ◽  
Atomic Physics ◽  
Solar Flares ◽  
Solar Maximum ◽  
Emission Lines ◽  
Atomic Data ◽  
Solar Maximum Mission ◽  
X Ray ◽  
Physical Conditions ◽  
Recombination Processes

Solar flare spectra in the ultraviolet and X-ray wavelength regions are rich in emission lines from highly ionized ions, formed at temperatures around 10 7 K. These lines can be used as valuable diagnostics for probing the physical conditions in solar flares. Such analyses require accurate atomic data for excitation, ionization and recombination processes. In this paper, we present a review of work which has already been carried out, in particular for the Solar Maximum Mission observations, and we look to future requirements for Solar-A .

scholarly journals Electrons and X-Ray Emission of Solar Flares

1990 ◽  
Vol 142 ◽  
pp. 409-413
Author(s):  
V. G. Kurt
Keyword(s):  
Solar Activity ◽  
Statistical Analysis ◽  
Solar Flare ◽  
Frequency Dependence ◽  
Power Law ◽  
Solar Flares ◽  
X Rays ◽  
Fast Electrons ◽  
X Ray ◽  
Flare Frequency

A statistical analysis of solar flare X-rays and interplanetary particle fluxes, measured onboard VENERA-13, 14 Spacecraft, was performed. The correlation of fluences for different manifestations of solar flares is strong, especially for fast electrons and hard and soft X-ray emissions. Frequency dependence on fluence value ϵi for practically all Kinds of solar flare emission can be described by power law ν (ϵ > ϵO) ∼ ϵ−0.45±0.15 which does not change significantly with solar activity. For different Hα flare importances the values of ϵi were obtained. It is proposed that appearance of certain energy flare frequency is strongly dependent on some scale factor.

scholarly journals Comments on: Confirming geomagnetic Sfe by means of a solar flare detector based on GNSS

2020 ◽  
Vol 10 ◽  
pp. 15
Author(s):  
Manuel Hernández-Pajares ◽  
Alberto García-Rigo
Keyword(s):  
Solar Flare ◽  
Space Weather ◽  
Solar Flares ◽  
Electron Content ◽  
Link Type ◽  
Previous Definition ◽  
Subsolar Point ◽  
Gnss Data

We report two comments affecting the paper “Curto JJ, Juan JM & Timoté CC, 2019. Confirming geomagnetic Sfe by means of a solar flare detector based on GNSS. J Space Weather Space Clim 9: A42. https://doi.org/10.1051/swsc/2019040”: The first comment is the reporting of two mistakes which distorts the central model used for the measurement and detection of solar flares with GNSS, that might affect as well the most part of results and discussions contained in the paper. And the second comment is the clarification about the authors’ claim of presenting the first work of using the electron content enhancement estimation at the subsolar point for characterizing solar flares with GNSS data, which is not accurate due to the existence of such previous definition and usage.

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