scholarly journals The Dynamic Evolutionary Processes of the Magnetic Fields in the Solar Active Region Boulder 5395

1993 ◽  
Vol 141 ◽  
pp. 457-460
Author(s):  
Xin Ping Liu ◽  
Hong Qi Zhang ◽  
Jing Lin ◽  
Gui Lin Liu

AbstractIn this paper, based on observational information we proposed an opening bipolar magnetic field model and studied numerically the dynamic evolutionary processes of the magnetic fields by solving a complete set of MHD equations. The aim is to discuss one of the mechanisms of energy build up of solar flares produced in the active region Boulder 5395.

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Yang Zhong ◽  
Chun-Bin Yang ◽  
Xu Cai ◽  
Sheng-Qin Feng

The features of magnetic field in relativistic heavy-ion collisions are systematically studied by using a modified magnetic field model in this paper. The features of magnetic field distributions in the central point are studied in the RHIC and LHC energy regions. We also predict the feature of magnetic fields at LHCsNN=900, 2760, and 7000 GeV based on the detailed study at RHICsNN=62.4, 130, and 200 GeV. The dependencies of the features of magnetic fields on the collision energies, centralities, and collision time are systematically investigated, respectively.


2002 ◽  
Vol 12 ◽  
pp. 396-397
Author(s):  
H.N. Wang ◽  
G.Q. Zhang ◽  
C.L. Zhu ◽  
J.L. Sun

AbstractThe authors propose a number of empirical criteria for prediction of solar flares based on many years of observations at Huairou Solar Observing Station of Beijing Astronomical Observatory.


1989 ◽  
Vol 104 (2) ◽  
pp. 219-222
Author(s):  
Ai Guoxiang ◽  
Li Jing

By means of Solar Magnetic Field Telescope, the fine structure of video magnetic fields (5324A) and sight-of-line velocity fields (4861A) of flare active region on July 23 (E53, S19) and Aug. 8(W25, S28) in 1987 has been obtained. The main characters are following:1. The flares occur in places where there are compressive and osmotic motion between opposite magnetic poles. In some causes, the osmotic opposite magnetic pole dissipates after the flares.


2018 ◽  
Vol 145 ◽  
pp. 03004
Author(s):  
Polya Dobreva ◽  
Olga Nitcheva ◽  
Monio Kartalev

This paper presents a case study of the plasma parameters in the magnetosheath, based on THEMIS measurements. As a theoretical tool we apply the self-consistent magnetosheath-magnetosphere model. A specific aspect of the model is that the positions of the bow shock and the magnetopause are self-consistently determined. In the magnetosheath the distribution of the velocity, density and temperature is calculated, based on the gas-dynamic theory. The magnetosphere module allows for the calculation of the magnetopause currents, confining the magnetic field into an arbitrary non-axisymmetric magnetopause. The variant of the Tsyganenko magnetic field model is applied as an internal magnetic field model. As solar wind monitor we use measurements from the WIND spacecraft. The results show that the model quite well reproduces the values of the ion density and velocity in the magnetosheath. The simlicity of the model allows calulations to be perforemed on a personal computer, which is one of the mean advantages of our model.


Author(s):  
Richard Holme ◽  
Nils Olsen ◽  
Martin Rother ◽  
Hermann Lühr

Author(s):  
Paul A. Mason ◽  
G. Chanmugam ◽  
I. L. Andronov ◽  
S. V. Koleskinov ◽  
E. P. Pavlenko ◽  
...  

Author(s):  
V Lesur ◽  
F Vervelidou

Summary We investigate to which extent the radially averaged magnetisation of the lithosphere can be recovered from the information content of a spherical harmonic model of the generated magnetic field when combined with few simple hypotheses. The results obtained show firstly that a hypothesis of magnetisation induced by a field of internal origin, even over a localised area, is not sufficient to recover uniquely the radially averaged magnetisation and, secondly, that this magnetisation can be recovered when a constant magnetisation direction is assumed. An algorithm to recover the magnetisation direction and distribution is then described and tested over a synthetic example. It requires to introduce a cost function that vanishes when estimated in a system of coordinates with its Z axis aligned with the magnetisation direction. Failing to find a vanishingly small value for the cost function is an indication that a constant magnetisation direction is not a valid hypothesis for the studied magnetic field model. The range of magnetisation directions that are compatible with the magnetic field model and a given noise level, can also be estimated. The whole process is illustrated by analysing a local, isolated maximum of the Martian magnetic field.


1996 ◽  
Vol 160 ◽  
pp. 49-50
Author(s):  
Naoki Itoh ◽  
Takemi Kotouda

Monte Carlo simulations of the evolution of pulsars are carried out in order to compare with the recent measurement of the pulsar transverse velocity by Lyne & Lorimer (1994). The new electron density distribution model of Taylor & Cordes (1993) is adopted in the simulation. Accurate pulsar orbits in the Galactic gravitational field are calculated. It is found that the constant magnetic field model of pulsars can account for the new measurement of the pulsar transverse velocity and the apparent correlation between the strength of the magnetic field and the transverse velocity of the pulsars. The present finding confirms the validity of the constant magnetic field model of pulsars and consolidates the idea that the apparent correlation between the strength of the magnetic field and the transverse velocity of the pulsars is caused by observational selection effects.


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