Evolution of magnetic flux ropes associated with flux transfer events and interplanetary magnetic clouds

1991 ◽  
Vol 96 (A2) ◽  
pp. 1619-1632 ◽  
Author(s):  
C. Q. Wei ◽  
L. C. Lee ◽  
S. Wang ◽  
S.-I. Akasofu
Keyword(s):  
Magnetic Flux ◽  
Magnetic Clouds ◽  
Magnetic Flux Ropes ◽  
Flux Transfer Events ◽  
Flux Ropes ◽  
Flux Transfer

scholarly journals The structure of flux transfer events recovered from Cluster data

2006 ◽  
Vol 24 (2) ◽  
pp. 603-618 ◽  
Author(s):  
H. Hasegawa ◽  
B. U. Ö. Sonnerup ◽  
C. J. Owen ◽  
B. Klecker ◽  
G. Paschmann ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Rope ◽  
Time Interval ◽  
Reconstruction Technique ◽  
Magnetic Flux Ropes ◽  
Flux Transfer Events ◽  
Cluster Data ◽  
Flux Ropes ◽  
Flux Transfer

Abstract. The structure and formation mechanism of a total of five Flux Transfer Events (FTEs), encountered on the equatorward side of the northern cusp by the Cluster spacecraft, with separation of ~5000 km, are studied by applying the Grad-Shafranov (GS) reconstruction technique to the events. The technique generates a magnetic field/plasma map of the FTE cross section, using combined magnetic field and plasma data from all four spacecraft, under the assumption that the structure is two-dimensional (2-D) and time-independent. The reconstructed FTEs consist of one or more magnetic flux ropes embedded in the magnetopause, suggesting that multiple X-line reconnection was involved in generating the observed FTEs. The dimension of the flux ropes in the direction normal to the magnetopause ranges from about 2000 km to more than 1 RE. The orientation of the flux rope axis can be determined through optimization of the GS map, the result being consistent with those from various single-spacecraft methods. Thanks to this, the unambiguous presence of a strong core field is confirmed, providing evidence for component merging. The amount of magnetic flux contained within each flux rope is calculated from the map and, by dividing it by the time interval between the preceding FTE and the one reconstructed, a lower limit of the reconnection electric field during the creation of the flux rope can be estimated; the estimated value ranges from ~0.11 to ~0.26 mV m-1, with an average of 0.19 mV m-1. This can be translated to the reconnection rate of 0.038 to 0.074, with an average of 0.056. Based on the success of the 2-D model in recovering the observed FTEs, the length of the X-lines is estimated to be at least a few RE.

Study of flux-rope characteristics at sub-astronomical-unit distances using the Helios 1 and 2 spacecraft

2020 ◽  
Vol 495 (2) ◽  
pp. 1566-1576
Author(s):  
Anil Raghav ◽  
Sandesh Gaikwad ◽  
Yuming Wang ◽  
Zubair I Shaikh ◽  
Wageesh Mishra ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Magnetic Energy ◽  
Ambient Medium ◽  
Flux Rope ◽  
Magnetic Clouds ◽  
Astronomical Unit ◽  
Magnetic Flux Ropes ◽  
Flux Ropes ◽  
External Conditions ◽  
Internal Properties

ABSTRACT Magnetic flux ropes observed as magnetic clouds near 1 au have been extensively studied in the literature and their distinct features are derived using numerous models. These studies summarize the general characteristics of flux ropes at 1 au without providing an understanding of the continuous evolution of the flux ropes from near the Sun to 1 au. In the present study, we investigate 26 flux ropes observed by the Helios 1 and 2 spacecraft (from 0.3 to 1 au) using the velocity-modified Gold–Hoyle model. The correlation and regression analyses suggest that the expansion speed, poloidal speed, total magnetic helicity and twist per au of the flux rope are independent of heliospheric distance. The study implies that the aforementioned features are more strongly influenced by their internal properties compared with external conditions in the ambient medium. Moreover, the poloidal magnetic flux and magnetic energy of the studied flux ropes exhibit power-law dependence on heliospheric distance. A better understanding of the underlying physics and corroboration of these results is expected from the Parker Solar Probe measurements in the near future.

scholarly journals Dual-spacecraft observation of large-scale magnetic flux ropes in the Martian ionosphere

2011 ◽  
Vol 116 (A2) ◽  
pp. n/a-n/a ◽  
Author(s):  
D. D. Morgan ◽  
D. A. Gurnett ◽  
F. Akalin ◽  
D. A. Brain ◽  
J. S. Leisner ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Large Scale ◽  
Magnetic Flux Ropes ◽  
Flux Ropes ◽  
Martian Ionosphere

scholarly journals Understanding the Twist Distribution Inside Magnetic Flux Ropes by Anatomizing an Interplanetary Magnetic Cloud

2018 ◽  
Vol 123 (5) ◽  
pp. 3238-3261 ◽  
Author(s):  
Yuming Wang ◽  
Chenglong Shen ◽  
Rui Liu ◽  
Jiajia Liu ◽  
Jingnan Guo ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Magnetic Cloud ◽  
Magnetic Flux Ropes ◽  
Flux Ropes

Plasma and magnetic field characteristics of magnetic flux transfer events

1982 ◽  
Vol 87 (A4) ◽  
pp. 2159 ◽  
Author(s):  
G. Paschmann ◽  
G. Haerendel ◽  
I. Papamastorakis ◽  
N. Sckopke ◽  
S. J. Bame ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Transfer Events ◽  
Flux Transfer

Dayside Magnetopause Reconnection and Flux Transfer Events: BepiColombo Earth-Flyby

2021 ◽  
Author(s):  
Wei-Jie Sun ◽  
James Slavin ◽  
Rumi Nakamura ◽  
Daniel Heyner ◽  
Johannes Mieth
Keyword(s):  
Magnetic Field ◽  
Large Scale ◽  
European Space Agency ◽  
Flux Rope ◽  
Transfer Event ◽  
Flux Transfer Events ◽  
Space Agency ◽  
Flux Ropes ◽  
Flux Transfer ◽  
Magnetospheric Multiscale Mission

<p>BepiColombo is a joint mission of the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) to the planet Mercury. The BepiColombo mission consists of two spacecraft, which are the Mercury Planetary Orbiter (MPO) and Mercury Magnetospheric Orbiter (Mio). The mission made its first planetary flyby, which is the only Earth flyby, on 10 April 2020, during which several instruments collected measurements. In this study, we analyze MPO magnetometer (MAG) observations of Flux Transfer Events (FTEs) in the magnetosheath and the structure of the subsolar magnetopause near the  flow stagnation point. The magnetosheath plasma beta was high with a value of ~ 8 and the interplanetary magnetic field (IMF) was southward with a clock angle that decreased from ~ 100 degrees to ~ 150 degrees.  As the draped IMF became increasingly southward several of the flux transfer event (FTE)-type flux ropes were observed. These FTEs traveled southward indicating that the magnetopause X-line was located northward of the spacecraft, which is consistent with a dawnward tilt of the IMF. Most of the FTE-type flux ropes were in ion-scale, <10 s duration, suggesting that they were newly formed. Only one large-scale FTE-type flux rope, ~ 20 s, was observed. It was made up of two successive bipolar signatures in the normal magnetic field component, which is evidence of coalescence at a secondary reconnection site. Further analysis demonstrated that the dimensionless reconnection rate of the re-reconnection associated with the coalescence site was ~ 0.14. While this investigation was limited to the MPO MAG observations, it strongly supports a key feature of dayside reconnection discovered in the Magnetospheric Multiscale mission, the growth of FTE-type flux ropes through coalescence at secondary reconnection sites.</p>

scholarly journals Investigating 1st and 2nd order Fermi acceleration of energetic particles by small-scale magnetic flux ropes at 1AU

2020 ◽  
Vol 1620 ◽  
pp. 012008
Author(s):  
J A le Roux ◽  
G M Webb ◽  
O V Khabarova ◽  
K T Van Eck ◽  
L-L Zhao ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Energetic Particles ◽  
Small Scale ◽  
Fermi Acceleration ◽  
Magnetic Flux Ropes ◽  
Flux Ropes
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