Magnetic clouds of oblate shapes

2005 ◽  
Vol 53 (1-3) ◽  
pp. 19-24 ◽  
Author(s):  
M. Vandas ◽  
E. Romashets ◽  
S. Watari
Keyword(s):  
Magnetic Clouds

scholarly journals Flux rope axis geometry of magnetic clouds deduced from in situ data

2013 ◽  
Vol 8 (S300) ◽  
pp. 265-268
Author(s):  
Miho Janvier ◽  
Pascal Démoulin ◽  
Sergio Dasso
Keyword(s):  
Interplanetary Medium ◽  
Magnetic Cloud ◽  
Flux Rope ◽  
Magnetic Clouds ◽  
Direct Integration ◽  
Axis Orientation ◽  
In Situ Data ◽  
Geometrical Features ◽  
Wide Range

AbstractMagnetic clouds (MCs) consist of flux ropes that are ejected from the low solar corona during eruptive flares. Following their ejection, they propagate in the interplanetary medium where they can be detected by in situ instruments and heliospheric imagers onboard spacecraft. Although in situ measurements give a wide range of data, these only depict the nature of the MC along the unidirectional trajectory crossing of a spacecraft. As such, direct 3D measurements of MC characteristics are impossible. From a statistical analysis of a wide range of MCs detected at 1 AU by the Wind spacecraft, we propose different methods to deduce the most probable magnetic cloud axis shape. These methods include the comparison of synthetic distributions with observed distributions of the axis orientation, as well as the direct integration of observed probability distribution to deduce the global MC axis shape. The overall shape given by those two methods is then compared with 2D heliospheric images of a propagating MC and we find similar geometrical features.

scholarly journals Solar cycle evolution of the structure of magnetic clouds in the inner heliosphere

1998 ◽  
Vol 25 (15) ◽  
pp. 2959-2962 ◽  
Author(s):  
T. Mulligan ◽  
C. T. Russell ◽  
J. G. Luhmann
Keyword(s):  
Solar Cycle ◽  
Magnetic Clouds ◽  
Inner Heliosphere

The flux of flux ropes embedded within magnetic clouds near 5 AU

2021 ◽  
Author(s):  
Yan Zhao ◽  
Hengqiang Feng ◽  
Qiang Liu ◽  
Ake Zhao ◽  
Guoqing Zhao ◽  
...  
Keyword(s):  
Magnetic Clouds ◽  
Flux Ropes

The Twist Profile in the Cross Section of Interplanetary Magnetic Clouds

2018 ◽  
Vol 869 (1) ◽  
pp. L13 ◽  
Author(s):  
Ake Zhao ◽  
Yuming Wang ◽  
Hengqiang Feng ◽  
Mengjiao Xu ◽  
Yan Zhao ◽  
...  
Keyword(s):  
Cross Section ◽  
Magnetic Clouds ◽  
The Cross

scholarly journals A summary of WIND magnetic clouds for years 1995-2003: model-fitted parameters, associated errors and classifications

2006 ◽  
Vol 24 (1) ◽  
pp. 215-245 ◽  
Author(s):  
R. P. Lepping ◽  
D. B. Berdichevsky ◽  
C.-C. Wu ◽  
A. Szabo ◽  
T. Narock ◽  
...  
Keyword(s):  
Temperature Drop ◽  
Model Fitting ◽  
Sunspot Cycle ◽  
Flux Rope ◽  
Axial Current ◽  
Model Fit ◽  
Magnetic Clouds ◽  
Symmetric Model ◽  
Large Set ◽  
Interplanetary Shocks

Abstract. Interplanetary magnetic clouds (MCs) have been identified for the first 8.6 years of the WIND mission, and their magnetic field structures have been parameter-fitted by a static, force free, cylindrically-symmetric model (Lepping et al., 1990) with various levels of success. This paper summarizes various aspects of the results of the model fitting by providing: seven estimated model fit-parameter values for each of the 82 MCs found, their objectively determined quality estimates, closest approach vectors (in two coordinate frames), fit-parameter errors for the cases of acceptable quality (50 cases, or 61%), axial magnetic fluxes, axial current densities, and total axial current - as well as some examples of MC profiles for various conditions and "categories" for each case (e.g. Bz: N→S or S→N, etc.). MC quality is estimated from a quantitative consideration of a large set of parameters, such as the chi-squared of the model fit, degree of asymmetry of the B profile, and a comparison of two means of estimating radius. This set of MCs was initially identified by visual inspection of relevant field and plasma data. Each resulting MC candidate is then tested through the use of the MC parameter model, for various adjusted durations to determine the best fit, which helps to refine the boundary-times. The resulting MC set is called Set 1. Another, larger, set (Set 2) of MCs is identified through an automated program whose criteria are based on general MC plasma and field characteristics at 1AU determined through past experience. Set 1 is almost fully contained within Set 2, whose frequency of occurrence better matches that of the sunspot cycle than Set 1. The difference-set (Set 2-Set 1) is referred to as the magnetic cloud-like (MCL) set, whose members do not very well represent good flux ropes through modeling. We present a discussion of how a MC's front boundary is specifically identified in terms of multi-parameter considerations (i.e. any one or more of: increase in B, directional discontinuity, magnetic hole in B, drop in proton plasma beta, B-fluctuation level change, proton temperature drop, etc.), as well as through the application of the flux rope model. Also presented are examples of unusual MCs, as well as some commonly occurring relationships, such as the existence and frequency (approx. 1/2 the time) of upstream interplanetary shocks, and less frequent internal shocks.

scholarly journals Global and local expansion of magnetic clouds in the inner heliosphere

2009 ◽  
Vol 509 ◽  
pp. A39 ◽  
Author(s):  
A. M. Gulisano ◽  
P. Démoulin ◽  
S. Dasso ◽  
M. E. Ruiz ◽  
E. Marsch
Keyword(s):  
Magnetic Clouds ◽  
Local Expansion ◽  
Global And Local ◽  
Inner Heliosphere
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