scholarly journals Transient Events and Their Solar Magnetic Field

1998 ◽  
Vol 11 (2) ◽  
pp. 877-879
Author(s):  
J.-C. Vial
Keyword(s):  
Magnetic Field ◽  
Particle Acceleration ◽  
Magnetic Fields ◽  
Coronal Mass Ejections ◽  
Solar Magnetic Field ◽  
Solar Magnetic Fields ◽  
Radio Network ◽  
Excellent Review ◽  
X Ray ◽  
Transient Events

Excellent review papers have been presented in this session by S. Solanki (Manifestations of solar magnetic fields), K. Dere (Coronal Mass Ejections and interplanetary ejecta) and W. Droege (Particle acceleration by waves and fields) and the relevant texts can be found in this volume.The Joint Discussion benefited from three contributed papers: X-Ray/Radio network flares of the quiet Sun by A.O. Benz, S. Krucker, L.W. Acton, and T.S. Bastian (presented by A.O. Benz) Radio observations of coronal X-ray jets by M.R. Kundu

scholarly journals Progress in the Measurement of Solar Magnetic Fields

1993 ◽  
Vol 141 ◽  
pp. 149-155 ◽  
Author(s):  
Guoxiang Ai
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
White Light ◽  
Historical Development ◽  
Solar Magnetic Field ◽  
Solar Physics ◽  
Monochromatic Light ◽  
Velocity Fields ◽  
Solar Magnetic Fields ◽  
Optical Instruments

AbstractThe historical development of optical instruments for solar physics is outlined, from white light to unpolarized and polarized monochromatic light, to Stokes profiles and simultaneous fields of view, from points to lines, plane to cube. An evolutionary series and classificaton of instruments for the solar magnetic field is described. As a next step the 2-D real time polarizing spectrograph has been proposed. The planned instruments in China for measurements of solar magnetic and velocity fields are briefly introduced.

scholarly journals Analog Video Magnetograms in Real Time

1971 ◽  
Vol 43 ◽  
pp. 76-83 ◽  
Author(s):  
R. C. Smithson ◽  
R. B. Leighton
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Magnetic Field ◽  
Solar Spectrum ◽  
Zeeman Splitting ◽  
The Other ◽  
Line Of Sight ◽  
Zero Field ◽  
The Sun ◽  
Solar Magnetic Fields

For many years solar magnetic fields have been measured by a variety of techniques, all of which exploit the Zeeman splitting of lines in the solar spectrum. One of these techniques (Leighton, 1959) involves a photographic subtraction of two monochromatic images to produce a picture of the Sun in which the line-of-sight component of the solar magnetic field appears as various shades of gray. In a magnetogram made by this method, zero field strength appears as neutral gray, while magnetic fields of one polarity or the other appear as lighter or darker areas, respectively. Figure 1 shows such a magnetogram.

scholarly journals Large-Scale Solar Magnetic Fields

1976 ◽  
Vol 71 ◽  
pp. 47-67 ◽  
Author(s):  
V. Bumba
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Distribution ◽  
Large Scale ◽  
Solar Magnetic Field ◽  
Magnetic Measurements ◽  
Preliminary Investigation ◽  
Longitudinal Distribution ◽  
Solar Magnetic Fields ◽  
Background Fields

The characteristics of the large-scale distribution of the solar magnetic fields on the basis of a series of solar magnetic synoptic charts covering more than 15 years of observations are given. The major part of our information concerns the morphology and only some results deal with the kinematics of the field distribution. Results of averaged solar magnetic field fluxes and polarity reversal studies as well as of preliminary investigation of the very-low angular resolution magnetic measurements are given. The regular zonal and sectoral distribution of photospheric background fields, the different role or visibility of structures in both polarities is discussed. The reflection of both main types of the longitudinal distribution of large-scale solar background magnetic fields (the 27-day, the 28–29-day successions, the ‘supergiant’ structures) in the interplanetary magnetic field distribution is also considered.

scholarly journals Manifestations of Solar Magnetic Fields

1998 ◽  
Vol 11 (2) ◽  
pp. 857-860
Author(s):  
S.K. Solanki
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Magnetic Field ◽  
Magnetic Activity ◽  
The Sun ◽  
Solar Magnetic Fields ◽  
Quiet Sun ◽  
Solar Magnetic Activity

AbstractThe magnetism of the Sun manifests itself in innumerable ways, many of which constitute what is referred to as solar magnetic activity, while others are counted among the phenomena of the quiet Sun. After a brief overview of the structure of the solar magnetic field, a few examples of its manifestations are pointed out.

RSFP PREDICTIONS FOR TRANSVERSE SOLAR MAGNETIC FIELD DISTRIBUTION FROM SOLAR NEUTRINO DATA

1998 ◽  
Vol 13 (15) ◽  
pp. 1163-1170 ◽  
Author(s):  
B. C. CHAUHAN ◽  
U. C. PANDEY ◽  
S. DEV
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Distribution ◽  
Magnetic Moment ◽  
Solar Neutrino ◽  
Solar Magnetic Field ◽  
Magnetic Field Distribution ◽  
The Sun ◽  
Solar Magnetic Fields ◽  
The Magnetic Field

Even though the standard solar model (SSM) has been very successful in predicting the thermal and nuclear evolution of the Sun, it does not throw enough light on solar magnetic activity. In the absence of a generally accepted theory of solar dynamo, various general arguments have been put forth to constrain solar magnetic fields. In the absence of reliable knowledge of solar magnetic fields from available astrophysical data, it may be worthwhile to constrain the solar magnetic fields from solar neutrino observations assuming Resonant Spin-Flavor Precession (RSFP) to be responsible for the solar neutrino deficit. The configuration of solar magnetic field derived in this work is in reasonably good agreement with the magnetic field distribution proposed by Akhmedov et al. (Sov. Phys. JETP68, 250 (1989)). However, the magnetic field distribution in the radiation zone used by Pulido (Phys. Rep.211, 167 (1992)) is ruled out. The magnitude of the magnetic field in the radiation and convective zones of the Sun are very sensitive to the value chosen for the neutrino magnetic moment. However, any change in the value of neutrino magnetic moment does not affect the magnetic field distribution as it only scales the magnetic field strength at different points by the same amount.

scholarly journals A Statistical Study on Force-Freeness of Solar Magnetic Fields in the Photosphere

2013 ◽  
Vol 30 ◽  
Author(s):  
S. Liu ◽  
J. T. Su ◽  
H. Q. Zhang ◽  
Y. Y. Deng ◽  
Y. Gao ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Magnetic Field ◽  
Statistical Study ◽  
Solar Magnetic Fields ◽  
Free Model ◽  
Free Fields ◽  
Heliocentric Coordinates ◽  
Statistical Results ◽  
Calibration Coefficients

AbstractIt is an indisputable fact that solar magnetic fields are force-free in the corona, where force-free fields mean that current and magnetic fields are parallel and there is no Lorentz force in the fields. While the force-free extent of photospheric magnetic fields remains open, in this paper, we give its statistical results. Vector magnetograms (namely, Bx, By, and Bz in heliocentric coordinates) employed are observed by the Solar Magnetic Field Telescope at Huairou Solar Observing Station. We study and calibrate 925 magnetograms calibrated by two sets of calibration coefficients, which indicate the relation between magnetic fields and the strength of the Stokes spectrum and can be calculated either theoretically or empirically. The statistical results show that the majority of active region magnetic fields are not consistent with the force-free model.

Facular Models, the K-Line, and Magnetic Fields

1977 ◽  
Vol 4 (2) ◽  
pp. 261-264
Author(s):  
G. A. Chapman
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Atomic Physics ◽  
Solar Magnetic Field ◽  
Good Description ◽  
Velocity Fields ◽  
Small Scale ◽  
Solar Magnetic Fields ◽  
Spectroscopic Observations ◽  
Spatially Resolved

Photospheric faculae are now believed to be closely associated with the small-scale solar magnetic field. In order to obtain reliable observations of solar magnetic fields, one needs to have a good description of faculae, which is presently lacking. The problem in obtaining good observational data is severe because faculae are usually not spatially resolved, particularly so in the case of spectroscopic observations. Proper use of spectroscopic observations also requires some knowledge of solar velocity fields and atomic physics in the case of a non LTE analysis. Many of these problems can be avoided by making use of the wings of the Ca II K-line. The wing of this line is unaffected by magnetic and velocity effects. The formation of the line has become increasingly well understood and most of the wing (with the exception of the inner 1 - 2 Å) is formed in LTE. The line is so strong that its formation spans the whole depth of the photosphere.

RESOLUTION OF THE Be/B SOLAR NEUTRINO FLUX ANOMALY IN THE RESONANT SPIN-FLAVOR PRECESSION SCENARIO WITH TWISTING SOLAR MAGNETIC FIELDS

2000 ◽  
Vol 15 (05) ◽  
pp. 351-360
Author(s):  
S. DEV ◽  
JYOTI DHAR SHARMA
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Seasonal Variations ◽  
Solar Neutrino ◽  
Solar Magnetic Field ◽  
Neutrino Flux ◽  
The Other ◽  
Complete Disappearance ◽  
Solar Magnetic Fields ◽  
Solar Neutrino Flux

The Be/B neutrino flux anomaly has been examined within the framework of the resonant spin-flavor precession scenario with twisting solar magnetic fields. It is found that the twist of the toroidal component of the solar magnetic field, leads naturally to a complete disappearance of 7 Be neutrinos emerging from one of the solar hemispheres. However, the 7 Be neutrino flux emerging from the other solar hemisphere with oppositely twisted magnetic field must survive completely. Thus, this scenario predicts seasonal variations of the 7 Be neutrino flux to be observed in the Borexino experiment.

scholarly journals Scattering Polarisation of the d-States of Ions and Solar Magnetic Field: Effects of Isotropic Collisions

2017 ◽  
Vol 34 ◽  
Author(s):  
M. Derouich ◽  
H. Basurah ◽  
B. Badruddin
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Genetic Programming ◽  
Hyperfine Structure ◽  
Solar Magnetic Field ◽  
Solar Magnetic Fields ◽  
Magnetic Field Effects ◽  
Priority Area ◽  
Average Value ◽  
Solar Research

AbstractAnalysis of solar magnetic fields using observations as well as theoretical interpretations of the scattering polarisation is commonly designated as a high priority area of the solar research. The interpretation of the observed polarisation raises a serious theoretical challenge to the researchers involved in this field. In fact, realistic interpretations need detailed investigations of the depolarising collisions.The goal of this paper is to determine new relationships which allow the calculation of any collisional rates of the d-levels of ions by simply determining the value of n* and Ep without the need of determining treating the collisional problem.In this work, we applied our collisional code to a large number of cases involving complex and simple ions. After that, the results are injected in a genetic programming code in order to infer original relationships which will be of great help to solar applications. We discussed the accuracy of our collisional rates in the cases of complex atoms and atoms with hyperfine structure.We compared the results obtained through the new relationships with the results obtained directly by running our code of collisions. The percentage of error is about 10% in the average value.

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