scholarly journals The Distributions of Iron Average Charge States in Small Flux Ropes in Interplanetary Space: Clues to Their Twisted Structures

2018 ◽  
Vol 123 (9) ◽  
pp. 7167-7180 ◽  
Author(s):  
Jia Huang ◽  
Yong C.-M. Liu ◽  
Jun Peng ◽  
Zhaohui Qi ◽  
Hui Li ◽  
...  
Keyword(s):  
Interplanetary Space ◽  
Average Charge ◽  
Flux Ropes ◽  
Charge States

scholarly journals The Inhomogeneity of Composition Along the Magnetic Cloud Axis

2021 ◽  
Vol 9 ◽  
Author(s):  
Hongqiang Song ◽  
Qiang Hu ◽  
Xin Cheng ◽  
Jie Zhang ◽  
Leping Li ◽  
...  
Keyword(s):  
Cross Section ◽  
Interplanetary Space ◽  
Flux Rope ◽  
Ecliptic Plane ◽  
Magnetic Clouds ◽  
Ionic Charge ◽  
Elemental Abundances ◽  
Significant Difference ◽  
Flux Ropes ◽  
Charge States

Coronal mass ejections (CMEs) are one of the most energetic explosions in the solar system. It is generally accepted that CMEs result from eruptions of magnetic flux ropes, which are dubbed as magnetic clouds (MCs) in interplanetary space. The composition (including the ionic charge states and elemental abundances) is determined prior to and/or during CME eruptions in the solar atmosphere and does not alter during MC propagation to 1 AU and beyond. It has been known that the composition is not uniform within a cross section perpendicular to the MC axis, and the distribution of ionic charge states within a cross section provides us an important clue to investigate the formation and eruption processes of flux ropes due to the freeze-in effect. The flux rope is a three-dimensional magnetic structure intrinsically, and it remains unclear whether the composition is uniform along the flux rope axis as most MCs are only detected by one spacecraft. In this study, we report an MC that was observed by Advanced Composition Explorer at ∼1 AU during March 4–6, 1998, and Ulysses at ∼5.4 AU during March 24–28, 1998, sequentially. At these times, both spacecraft were located around the ecliptic plane, and the latitudinal and longitudinal separations between them were ∼2.2° and ∼5.5°, respectively. It provides us an excellent opportunity to explore the axial inhomogeneity of flux rope composition, as both spacecraft almost intersected the cloud center at different sites along its axis. Our study shows that the average values of ionic charge states exhibit significant difference along the axis for carbon, and the differences are relatively slight but still obvious for charge states of oxygen and iron as well as the elemental abundances of iron and helium. Besides the means, the composition profiles within the cloud measured by both spacecraft also exhibit some discrepancies. We conclude that the inhomogeneity of composition exists along the cloud axis.

Average charge states of heavy atoms in dilute hydrogen

2001 ◽  
Vol 64 (6) ◽  
Author(s):  
Yu. Ts. Oganessian ◽  
V. K. Utyonkov ◽  
Yu. V. Lobanov ◽  
F. Sh. Abdullin ◽  
A. N. Polyakov ◽  
...  
Keyword(s):  
Average Charge ◽  
Heavy Atoms ◽  
Charge States

scholarly journals A new technique for observationally derived boundary conditions for space weather

2018 ◽  
Vol 8 ◽  
pp. A26 ◽  
Author(s):  
Paolo Pagano ◽  
Duncan Hendry Mackay ◽  
Anthony Robinson Yeates
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Boundary Conditions ◽  
Space Weather ◽  
Weather Forecasting ◽  
Interplanetary Space ◽  
Time Dependent ◽  
Magnetic Flux Ropes ◽  
Mhd Simulations ◽  
Flux Ropes

Context. In recent years, space weather research has focused on developing modelling techniques to predict the arrival time and properties of coronal mass ejections (CMEs) at the Earth. The aim of this paper is to propose a new modelling technique suitable for the next generation of Space Weather predictive tools that is both efficient and accurate. The aim of the new approach is to provide interplanetary space weather forecasting models with accurate time dependent boundary conditions of erupting magnetic flux ropes in the upper solar corona. Methods. To produce boundary conditions, we couple two different modelling techniques, MHD simulations and a quasi-static non-potential evolution model. Both are applied on a spatial domain that covers the entire solar surface, although they extend over a different radial distance. The non-potential model uses a time series of observed synoptic magnetograms to drive the non-potential quasi-static evolution of the coronal magnetic field. This allows us to follow the formation and loss of equilibrium of magnetic flux ropes. Following this a MHD simulation captures the dynamic evolution of the erupting flux rope, when it is ejected into interplanetary space. Results.The present paper focuses on the MHD simulations that follow the ejection of magnetic flux ropes to 4 R⊙. We first propose a technique for specifying the pre-eruptive plasma properties in the corona. Next, time dependent MHD simulations describe the ejection of two magnetic flux ropes, that produce time dependent boundary conditions for the magnetic field and plasma at 4 R⊙ that in future may be applied to interplanetary space weather prediction models. Conclusions. In the present paper, we show that the dual use of quasi-static non-potential magnetic field simulations and full time dependent MHD simulations can produce realistic inhomogeneous boundary conditions for space weather forecasting tools. Before a fully operational model can be produced there are a number of technical and scientific challenges that still need to be addressed. Nevertheless, we illustrate that coupling quasi-static and MHD simulations in this way can significantly reduce the computational time required to produce realistic space weather boundary conditions.

High Minor Ion Outflow Speeds in the Inner Corona and Observed Ion Charge States in Interplanetary Space

1998 ◽  
Vol 498 (1) ◽  
pp. 448-457 ◽  
Author(s):  
Ruth Esser ◽  
Richard J. Edgar ◽  
Nancy S. Brickhouse
Keyword(s):  
Interplanetary Space ◽  
Ion Outflow ◽  
Charge States

scholarly journals Observations of Magnetic Flux Ropes Opened or Disconnected From the Sun by Magnetic Reconnection in Interplanetary Space

2021 ◽  
Vol 9 ◽  
Author(s):  
Hengqiang Feng ◽  
Yan Zhao ◽  
Jiemin Wang ◽  
Qiang Liu ◽  
Guoqing Zhao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Magnetic Reconnection ◽  
Interplanetary Space ◽  
Closed Field ◽  
Magnetic Flux Ropes ◽  
Flux Ropes ◽  
Solar Eruptions ◽  
Wind Spacecraft ◽  
Field Lines

During solar eruptions, many closed magnetic flux ropes are ejected into interplanetary space, which contribute to the heliospheric magnetic field and have important space weather effect because of their coherent magnetic field. Therefore, understanding the evolution of these closed flux ropes in the interplanetary space is important. In this paper, we examined all the magnetic and plasma data measured in 1997 by the Wind spacecraft and identified 621 reconnection exhausts. Of the 621 reconnection events, 31 were observed at the boundaries of magnetic flux ropes and were thought to cause the opening or disconnection magnetic field lines of the adjacent ropes. Of the 31 magnetic reconnection events, 29 were interchange reconnections and the closed field lines of these related flux ropes were opened by them. Only 2 of the 31 magnetic reconnection events disconnected the opened field lines of the original flux ropes. These observations indicate that interchange reconnection and disconnection may be two important mechanisms changing the magnetic topology of the magnetic flux ropes during their propagation during the interplanetary space.

scholarly journals Statistical Study of Small-Scale Interplanetary Magnetic Flux Ropes in the Vicinity of the Heliospheric Current Sheet

2021 ◽  
Vol 9 ◽  
Author(s):  
Qiang Liu ◽  
Yan Zhao ◽  
Guoqing Zhao
Keyword(s):  
Magnetic Flux ◽  
Current Sheet ◽  
Interplanetary Space ◽  
Axial Direction ◽  
Heliospheric Current Sheet ◽  
Normal Direction ◽  
Small Scale ◽  
Magnetic Structures ◽  
Magnetic Flux Ropes ◽  
Flux Ropes

The small-scale interplanetary magnetic flux ropes (SIMFRs) are common magnetic structures in the interplanetary space, yet their origination is still an open question. In this article, we surveyed 63 SIMFRs found within 6-day window around the heliospheric current sheet (HCS) and investigated their axial direction, as well as the local normal direction of the HCS. Results showed that the majority (48/63) of the SIMFRs were quasi-parallel to the associated HCS (i.e., the axial direction of SIMFRs was quasi-perpendicular to the normal direction of the associated HCS). They also showed that the SIMFRs quasi-parallel to the associated HCS statistically had shorter duration than the cases quasi-perpendicular. The results indicate that most of these SIMFRs may be generated in the nearby HCSs.

Sign in / Sign up

Export Citation Format

Share Document