scholarly journals Numerical simulation and data analysis of the 23 July 2012 SEP event observed by ACE, STEREO-A, and STEREO-B

2020 ◽  
Vol 637 ◽  
pp. A48 ◽  
Author(s):  
G. Qin ◽  
S.-Y. Qi
Keyword(s):  
Field Model ◽  
Three Dimensional ◽  
Energetic Particles ◽  
Interplanetary Coronal Mass Ejection ◽  
Parker Spiral ◽  
Magnetic Field Model ◽  
Perpendicular Diffusion ◽  
Multiple Spacecraft ◽  
Mass Ejection ◽  
The Relationship

An extremely powerful, superfast interplanetary coronal mass ejection (ICME) from the Sun on 23 July 2012 was detected by widely separated multiple spacecraft, namely STEREO-A, STEREO-B, and ACE, together with the ICME-driven shock and associated solar energetic particles (SEPs). We use the Parker spiral magnetic field model to analyze the relationship between the propagation of the shock and the SEP flux. Furthermore, we simulate the SEP event by numerically solving the three-dimensional focused transport equation of SEPs considering the shock as the moving source of energetic particles. To deal with the fact that protons and electrons behave completely differently for both parallel and perpendicular diffusion, for simplicity, we use the same diffusion model format for the simulations of protons and electrons but with different parameters. We find that the analysis can qualitatively explain the important features of the SEP flux observed by the multiple spacecraft simultaneously. In addition, the numerical results for both energetic protons and electrons approximately agree with multi-spacecraft observations.

scholarly journals THE VERY UNUSUAL INTERPLANETARY CORONAL MASS EJECTION OF 2012 JULY 23: A BLAST WAVE MEDIATED BY SOLAR ENERGETIC PARTICLES

2013 ◽  
Vol 770 (1) ◽  
pp. 38 ◽  
Author(s):  
C. T. Russell ◽  
R. A. Mewaldt ◽  
J. G. Luhmann ◽  
G. M. Mason ◽  
T. T. von Rosenvinge ◽  
...  
Keyword(s):  
Coronal Mass Ejection ◽  
Blast Wave ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Interplanetary Coronal Mass Ejection ◽  
Mass Ejection

Up and down cascades: Three-dimensional magnetic field model

2002 ◽  
Vol 65 (6) ◽  
Author(s):  
E. M. Blanter ◽  
M. G. Shnirman ◽  
J. L. Le Mouël
Keyword(s):  
Magnetic Field ◽  
Field Model ◽  
Three Dimensional ◽  
Magnetic Field Model

scholarly journals Correlation between auroral activity and rate of development of a storm in its main phase

2016 ◽  
Vol 2 (4) ◽  
pp. 9-12 ◽  
Author(s):  
Роман Бороев ◽  
Roman Boroev
Keyword(s):  
Magnetic Cloud ◽  
Main Phase ◽  
Phase Duration ◽  
Dst Index ◽  
Average Value ◽  
Interplanetary Coronal Mass Ejection ◽  
Ae Index ◽  
Index Variation ◽  
Mass Ejection ◽  
The Relationship

We investigated the relationship between the rate of storm development in its main phase (|ΔDst|/ΔT) and the average value (ΣAE/ΔT) of AE index for the main phase where |ΔDst| is a Dst-index variation, ΣAE is the total value of AE index for the main phase of magnetic storm, ΔT is the main phase duration. We considered storms initiated by corotating interaction region (CIR) and interplanetary coronal mass ejection (ICME) (magnetic cloud and ejecta). For CIR events, the value of ΣAE/ΔT is shown to correlate with the rate of storm development in its main phase, in contrast to the storms initiated by the ICME. As found, there is a weak correlation between ΣAE/ΔT and the minimum value of Dst index for CIR and ICME events.

scholarly journals Field line distribution of density at <I>L</I>=4.8 inferred from observations by CLUSTER

2009 ◽  
Vol 27 (2) ◽  
pp. 705-724 ◽  
Author(s):  
R. E. Denton ◽  
P. Décréau ◽  
M. J. Engebretson ◽  
F. Darrouzet ◽  
J. L. Posch ◽  
...  
Keyword(s):  
Field Line ◽  
Electron Density ◽  
Field Model ◽  
Mass Density ◽  
Local Maximum ◽  
Magnetic Equator ◽  
Alfven Wave ◽  
Ion Composition ◽  
Magnetic Field Model ◽  
Multiple Spacecraft

Abstract. For two events observed by the CLUSTER spacecraft, the field line distribution of mass density ρ was inferred from Alfvén wave harmonic frequencies and compared to the electron density ne from plasma wave data and the oxygen density nO+ from the ion composition experiment. In one case, the average ion mass M≈ρ/ne was about 5 amu (28 October 2002), while in the other it was about 3 amu (10 September 2002). Both events occurred when the CLUSTER 1 (C1) spacecraft was in the plasmatrough. Nevertheless, the electron density ne was significantly lower for the first event (ne=8 cm−3) than for the second event (ne=22 cm−3), and this seems to be the main difference leading to a different value of M. For the first event (28 October 2002), we were able to measure the Alfvén wave frequencies for eight harmonics with unprecedented precision, so that the error in the inferred mass density is probably dominated by factors other than the uncertainty in frequency (e.g., magnetic field model and theoretical wave equation). This field line distribution (at L=4.8) was very flat for magnetic latitude |MLAT|≲20° but very steeply increasing with respect to |MLAT| for |MLAT|≳40°. The total variation in ρ was about four orders of magnitude, with values at large |MLAT| roughly consistent with ionospheric values. For the second event (10 September 2002), there was a small local maximum in mass density near the magnetic equator. The inferred mass density decreases to a minimum 23% lower than the equatorial value at |MLAT|=15.5°, and then steeply increases as one moves along the field line toward the ionosphere. For this event we were also able to examine the spatial dependence of the electron density using measurements of ne from all four CLUSTER spacecraft. Our analysis indicates that the density varies with L at L~5 roughly like L−4, and that ne is also locally peaked at the magnetic equator, but with a smaller peak. The value of ne reaches a density minimum about 6% lower than the equatorial value at |MLAT|=12.5°, and then increases steeply at larger values of |MLAT|. This is to our knowledge the first evidence for a local peak in bulk electron density at the magnetic equator. Our results show that magnetoseismology can be a useful technique to determine the field line distribution of the mass density for CLUSTER at perigee and that the distribution of electron density can also be inferred from measurements by multiple spacecraft.

scholarly journals Coronal Loop Mapping to Infer the Best Magnetic Field Models for Active Region Prominences

2013 ◽  
Vol 8 (S300) ◽  
pp. 416-417
Author(s):  
G. Allen Gary ◽  
Qiang Hu ◽  
Jong Kwan Lee
Keyword(s):  
Magnetic Field ◽  
Coronal Loop ◽  
Field Model ◽  
Three Dimensional ◽  
Coronal Loops ◽  
Magnetic Field Model ◽  
Free Parameters ◽  
Field Lines ◽  
Fitness Parameter ◽  
The Magnetic Field

AbstractThis article comments on the results of a new, rapid, and flexible manual method to map on-disk individual coronal loops of a two-dimensional EUV image into the three-dimensional coronal loops. The method by Gary, Hu, and Lee (2013) employs cubic Bézier splines to map coronal loops using only four free parameters per loop. A set of 2D splines for coronal loops is transformed to the best 3D pseudo-magnetic field lines for a particular coronal model. The results restrict the magnetic field models derived from extrapolations of magnetograms to those admissible and inadmissible via a fitness parameter. This method uses the minimization of the misalignment angles between the magnetic field model and the best set of 3D field lines that match a set of closed coronal loops. We comment on the implication of the fitness parameter in connection with the magnetic free energy and comment on extensions of our earlier work by considering the issues of employing open coronal loops or employing partial coronal loop.

scholarly journals Correlation between auroral activity and rate of development of a storm in its main phase

2017 ◽  
Vol 2 (4) ◽  
pp. 11-15 ◽  
Author(s):  
Роман Бороев ◽  
Roman Boroev
Keyword(s):  
Magnetic Cloud ◽  
Main Phase ◽  
Phase Duration ◽  
Dst Index ◽  
Average Value ◽  
Interplanetary Coronal Mass Ejection ◽  
Ae Index ◽  
Index Variation ◽  
Mass Ejection ◽  
The Relationship

We investigated the relationship between the rate of storm development in its main phase (|ΔDst|/ΔT) and the average value (ΣAE/ΔT) of AE index for the main phase where |ΔDst| is the Dst-index variation, ΣAE is the total value of AE index for the main phase of magnetic storm, ΔT is the main phase duration. We considered storms initiated by corotating interaction region (CIR) and interplanetary coronal mass ejection (ICME) (magnetic cloud and ejecta). For CIR events, the value of ΣAE/ΔT is shown to correlate with the rate of storm development in its main phase in contrast to the storms initiated by the ICME. As found, there is a weak correlation between ΣAE/ΔT and the minimum value of Dst index for CIR and ICME events.

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