scholarly journals THE PROCESSES OF ENERGY RELEASE IN LOW-POWER SOLAR FLARES

2019 ◽  
Vol 5 (4) ◽  
pp. 3-11
Author(s):  
Aleksandr Borovik ◽  
Anton Zhdanov
Keyword(s):  
Solar Flare ◽  
Energy Range ◽  
Space Weather ◽  
Solar Flares ◽  
Rise Time ◽  
Total Duration ◽  
Flare Energy ◽  
Area Distribution ◽  
Class 1 ◽  
Statistical Studies

Using flare patrol data for 1972–2010 [http://www.ngdc.noaa.gov/stp/space-weather/solar-data/solar-features/solar-flares/], we have conducted statistical studies of small solar flares. We have established a correlation between the flare brightness rise time and the total duration of small flares, and obtained evidence of the discreteness of relative rise times (Trel). The most significant Trel values are 0.2, 0.25, 0.33, and 0.5. As the area class and importance of flares increase, maxima of Trel distributions decrease, flatten, and completely disappear in case of large flares. We have found the discreteness of the area distribution of small flares. We have obtained distributions of solar flare energy, which exhibit significant overlap for flare energy of different area classes. The energy range of large solar flares contains 9.5 % of small flares. The energy range of flares of area class 1 has even a more significant overlap.

scholarly journals THE PROCESSES OF ENERGY RELEASE IN LOW-POWER SOLAR FLARES

2019 ◽  
Vol 5 (4) ◽  
pp. 3-9
Author(s):  
Aleksandr Borovik ◽  
Anton Zhdanov
Keyword(s):  
Solar Flare ◽  
Energy Range ◽  
Space Weather ◽  
Solar Flares ◽  
Rise Time ◽  
Total Duration ◽  
Flare Energy ◽  
Area Distribution ◽  
Class 1 ◽  
Statistical Studies

Using flare patrol data for 1972–2010 [http://www.ngdc.noaa.gov/stp/space-weather/solar-data/solar-features/solar-flares/], we have conducted statistical studies of small solar flares. We have established a correlation between the flare brightness rise time and the total duration of small flares, and obtained evidence of the discreteness of relative rise times (Trel). The most significant Trel values are 0.2, 0.25, 0.33, and 0.5. As the area class and importance of flares increase, maxima of Trel distributions decrease, flatten, and completely disappear in case of large flares. We have found the discreteness of the area distribution of small flares. We have obtained distributions of solar flare energy, which exhibit significant overlap for flare energy of different area classes. The energy range of large solar flares contains 9.5 % of small flares. The energy range of flares of area class 1 has even a more significant overlap.

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.

scholarly journals The First Results from “Solar X-ray Spectrometer (SOXS)” Mission

2005 ◽  
Vol 13 ◽  
pp. 622-622 ◽  
Author(s):  
Rajmal Jain ◽  
Hemant Dave ◽  
P. Sreekumar ◽  
A. B. Shah ◽  
N. M. Vadher ◽  
...  
Keyword(s):  
Solid State ◽  
Solar Flare ◽  
Energy Range ◽  
Solar Flares ◽  
High Energy ◽  
Low Energy ◽  
Energy Detector ◽  
X Ray ◽  
Phoswich Detector ◽  
First Results

Abstract“Solar X-ray Spectrometer (SOXS)” mission on-board GSAT-2 Indian spacecraft was launched on 08 May 2003 by GSLV-D2 and deployed in geostationery orbit to study the X-ray emission from solar flares with high spectral and temporal resolution. The SOXS consists of two independent payloads viz. SOXS Low Energy Detector (SLD) payload, and SOXS High Energy Detector (SHD) payload. The SLD consists of two solid state detectors Si PIN and CZT, which cover the energy range from 4-60 keV, while the SHD has NaI(Tl)/CsI(Na) sandwiched phoswich detector that covers energy range from 20 keV to 10 MeV. We present very briefly the science objectives and instrumentation of SLD payload. After the successful In-orbit Tests (IOT), the first light was fed into SLD payload on 08 June 2003 when the solar flare was already in progress. We briefly present the first results from the SLD payload.

scholarly journals Space weather and earthquakes: possible triggering of seismic activity by strong solar flares

2020 ◽  
Vol 63 (5) ◽  
Author(s):  
Victor Novikov ◽  
Yuri Ruzhin ◽  
Valery Sorokin ◽  
Alexey Yaschenko
Keyword(s):  
Solar Flare ◽  
Space Weather ◽  
Solar Flares ◽  
Seismic Activity ◽  
Geomagnetic Storms ◽  
Time Window ◽  
Earthquake Source ◽  
Tien Shan ◽  
Earthquake Triggering ◽  
Power Sources

The studies completed to-date on a relation of the Earth’s seismicity and solar processes provided the fuzzy and contradictory results. The main problem of this research is a lack of physical explanation of a mechanism of earthquake triggering by strong variations of space weather conditions. Based on results obtained in the field and laboratory experiments on earthquake triggering by DC pulses injection into the Earth crust we may assume that the similar triggering phenomena may occur after the strong electromagnetic impact to the earthquake source due to solar flares or geomagnetic storms. Numerical estimations demonstrated that telluric currents induced by geomagnetic pulsations generated by solar flare have the similar density at the depth of earthquake source location (10-6 A/m2) in comparison with the current density generated by artificial power sources (10-7 – 10-8 A/m2) resulted in observed spatiotemporal redistribution of seismic activity in the regions of Pamirs and Northern Tien Shan. For supporting the idea of a possible earthquake triggering by solar flares we carried out a statistical analysis of global and regional (Greece) seismicity behavior during the solar flare of X9.3 class occurred on September 6, 2017 (the strongest flare over the past thirteen years). We have discovered a new evidence of earthquake triggering due to the Sun-Earth interaction by simple comparison of a number of earthquakes before and after the strong solar flare. The global number of earthquakes (USGS catalog, M ≥ 4) for time window of ±11 days after the solar flare has increased by 68%, and the regional seismicity (Greece, EMSC catalog, M ≥ 3) has increased by 120%.

scholarly journals Answer to the comments on “Confirming geomagnetic Sfe by means of a solar flare detector based on GNSS”

2020 ◽  
Vol 10 ◽  
pp. 16
Author(s):  
Juan José Curto ◽  
Jose Miguel Juan ◽  
Cristhian Camilo Timoté
Keyword(s):  
Solar Flare ◽  
Space Weather ◽  
Solar Flares ◽  
Link Type ◽  
Gnss Measurements

Hernández-Pajares and García-Rigo have written a document criticizing our paper “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” (Curto et al., 2019). The main goal of our paper was to define a methodology based on GNSS measurements that is able to detect solar flares (SF) in an automatic way. This methodology was used to confirm Sfe (SF effects) detected by geomagnetism in an unsupervised manner. In their document, Hernández-Pajares and García-Rigo posed two objections related to the correctness and the novelty of the methodology used in our paper. This document is a reply to these objections and concludes that they are not relevant.

Solar Flare Energetic Neutral Emission Measurements in the Project Coronas-I

1994 ◽  
Vol 144 ◽  
pp. 635-639
Author(s):  
J. Baláž ◽  
A. V. Dmitriev ◽  
M. A. Kovalevskaya ◽  
K. Kudela ◽  
S. N. Kuznetsov ◽  
...  
Keyword(s):  
Solar Flare ◽  
Energy Range ◽  
Gamma Rays ◽  
Pulse Shape ◽  
Gamma Ray ◽  
Pulse Shape Discrimination ◽  
Shape Discrimination ◽  
Solar Neutron ◽  
Low Altitude

AbstractThe experiment SONG (SOlar Neutron and Gamma rays) for the low altitude satellite CORONAS-I is described. The instrument is capable to provide gamma-ray line and continuum detection in the energy range 0.1 – 100 MeV as well as detection of neutrons with energies above 30 MeV. As a by-product, the electrons in the range 11 – 108 MeV will be measured too. The pulse shape discrimination technique (PSD) is used.

CHOICE OF CONDITIONS FOR MHD SIMULATIONS ABOVE THE ACTIVE REGION, ALLOWING THE STUDY OF THE SOLAR FLARE MECHANISM

2021 ◽  
Vol 44 ◽  
pp. 92-95
Author(s):  
A.I. Podgorny ◽  
◽  
I.M. Podgorny ◽  
A.V. Borisenko ◽  
N.S. Meshalkina ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Solar Flare ◽  
Magnetic Energy ◽  
Solar Radius ◽  
Computational Domain ◽  
Mhd Simulations ◽  
Flare Energy ◽  
Numerical Instabilities ◽  
The Magnetic Field

Primordial release of solar flare energy high in corona (at altitudes 1/40 - 1/20 of the solar radius) is explained by release of the magnetic energy of the current sheet. The observed manifestations of the flare are explained by the electrodynamical model of a solar flare proposed by I. M. Podgorny. To study the flare mechanism is necessary to perform MHD simulations above a real active region (AR). MHD simulation in the solar corona in the real scale of time can only be carried out thanks to parallel calculations using CUDA technology. Methods have been developed for stabilizing numerical instabilities that arise near the boundary of the computational domain. Methods are applicable for low viscosities in the main part of the domain, for which the flare energy is effectively accumulated near the singularities of the magnetic field. Singular lines of the magnetic field, near which the field can have a rather complex configuration, coincide or are located near the observed positions of the flare.

scholarly journals Gamma-rays from Solar Flares

2000 ◽  
Vol 195 ◽  
pp. 123-132 ◽  
Author(s):  
R. Ramaty ◽  
N. Mandzhavidze
Keyword(s):  
Energy Release ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
Particle Interaction ◽  
Mass Motion ◽  
Relativistic Electrons ◽  
Total Energy Release ◽  
Flare Energy ◽  
Accelerated Particles

Gamma-ray emission is the most direct diagnostic of energetic ions and relativistic electrons in solar flares. Analysis of solar flare gamma-ray data has shown: (i) ion acceleration is a major consequence of flare energy release, as the total flare energy in accelerated particles appears to be equipartitioned between ≳ 1 MeV/nucleon ions and ≳ 20 keV electrons, and amounts to an important fraction of the total energy release; (ii) there are flares for which over 50% of the energy is in a particles and heavier ions; (iii) in both impulsive and gradual flares, the particles that interact at the Sun and produce gamma rays are essentially always accelerated by the same mechanism that operates in impulsive flares, probably stochastic acceleration through gyroresonant wave particle interaction; and (iv) gamma-ray spectroscopy can provide new information on solar abundances, for example the site of the FIP-bias onset and the photospheric 3He abundance. We propose a new technique for the investigation of mass motion and mixing in the solar atmosphere: the observations of gamma-ray lines from long-term radioactivity produced by flare accelerated particles.

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