scholarly journals Evolution of interplanetary coronal mass ejections and magnetic clouds in the heliosphere

2013 ◽  
Vol 8 (S300) ◽  
pp. 245-254
Author(s):  
Pascal Démoulin
Keyword(s):  
Solar Wind ◽  
Physical Properties ◽  
Coronal Mass Ejections ◽  
Magnetic Measurements ◽  
Flux Rope ◽  
Magnetic Clouds ◽  
The Sun ◽  
Interplanetary Coronal Mass Ejections

AbstractInterplanetary Coronal Mass Ejections (ICMEs), and more specifically Magnetic Clouds (MCs), are detected with in situ plasma and magnetic measurements. They are the continuation of the CMEs observed with imagers closer to the Sun. A review of their properties is presented with a focus on their magnetic configuration and its evolution. Many recent observations, both in situ and with imagers, point to a key role of flux ropes, a conclusion which is also supported by present coronal eruptive models. Then, is a flux rope generically present in an ICME? How to quantify its 3D physical properties when it is detected locally as a MC? Is it a simple flux rope? How does it evolve in the solar wind? This paper reviews our present answers and limited understanding to these questions.

scholarly journals On the relationship between interplanetary coronal mass ejections and magnetic clouds

2013 ◽  
Vol 31 (7) ◽  
pp. 1251-1265 ◽  
Author(s):  
E. K. J. Kilpua ◽  
A. Isavnin ◽  
A. Vourlidas ◽  
H. E. J. Koskinen ◽  
L. Rodriguez
Keyword(s):  
Solar Wind ◽  
Coronal Mass Ejections ◽  
Flux Rope ◽  
Leading Edge ◽  
Magnetic Clouds ◽  
Interplanetary Coronal Mass Ejections ◽  
Magnetic Flux Ropes ◽  
Geometrical Effect ◽  
Relationship Of ◽  
The Relationship

Abstract. The relationship of magnetic clouds (MCs) to interplanetary coronal mass ejections (ICMEs) is still an open issue in space research. The view that all ICMEs would originate as magnetic flux ropes has received increasing attention, although near the orbit of the Earth only about one-third of ICMEs show clear MC signatures and often the MC occupies only a portion of the more extended region showing ICME signatures. In this work we analyze 79 events between 1996 and 2009 reported in existing ICME/MC catalogs (Wind magnetic cloud list and the Richardson and Cane ICME list) using near-Earth observations by ACE (Advanced Composition Explorer) and Wind. We perform a systematic comparison of cases where ICME and MC signatures coincided and where ICME signatures extended significantly beyond the MC boundaries. We find clear differences in the characteristics of these two event types. In particular, the events where ICME signatures continued more than 6 h past the MC rear boundary had 2.7 times larger speed difference between the ICME's leading edge and the preceding solar wind, 1.4 times higher magnetic fields, 2.1 times larger widths and they experienced three times more often strong expansion than the events for which the rear boundaries coincided. The events with significant mismatch in MC and ICME boundary times were also embedded in a faster solar wind and the majority of them were observed close to the solar maximum. Our analysis shows that the sheath, the MC and the regions of ICME-related plasma in front and behind the MC have different magnetic field, plasma and charge state characteristics, thus suggesting that these regions separate already close to the Sun. Our study shows that the geometrical effect (the encounter through the CME leg and/or far from the flux rope center) does not contribute much to the observed mismatch in the MC and ICME boundary times.

scholarly journals Coherence of Coronal Mass Ejections in Near-Earth Space

Solar Physics ◽  
2020 ◽  
Vol 295 (10) ◽  
Author(s):  
Mathew J. Owens
Keyword(s):  
Coronal Mass Ejections ◽  
Flux Rope ◽  
Angular Separation ◽  
Rapid Expansion ◽  
Magnetic Clouds ◽  
Angular Width ◽  
Limiting Factor ◽  
The Sun ◽  
Interplanetary Coronal Mass Ejections ◽  
Near Earth Space

Abstract Interplanetary coronal mass ejections (ICMEs) primarily move radially as they propagate away from the Sun, maintaining approximately constant angular width with respect to the Sun. As ICMEs have typical angular widths of around $60^{\circ }$ 60 ∘ , plasma elements on opposite flanks of an ICME separate in the non-radial direction at a speed, $v_{\mathrm{G}}$ v G , roughly equal to the ICME radial speed. This rapid expansion is a limiting factor on the propagation of information across an ICME at the local Alfvén speed, $v_{\mathrm{A}}$ v A . In this study, the 1-AU properties of ICMEs are used to compute two measures of ICME coherence. The first is the angular separation for which $v_{\mathrm{G}}$ v G exceeds the local $v_{\mathrm{A}}$ v A . The second measure is the angular extent over which a wavefront can propagate as an ICME travels from a given heliocentric distance to 1 AU. For both measures, ICMEs containing magnetic clouds show greater coherence than non-cloud ICMEs. However, even for magnetic clouds, information is unable to propagate across the full span of the structure. Thus interactions of ICMEs with other solar wind structures in the heliosphere are likely to lead to localised distortion, rather than solid-body like deflection. For magnetic clouds, the coherence length scale is significantly greater near the centre of the spacecraft encounter than at the leading or trailing edges. This suggests that magnetic clouds may be more coherent, and thus less prone to distortion, along the direction of the magnetic flux-rope axis than in directions perpendicular to the axis.

scholarly journals The role of aerodynamic drag in dynamics of coronal mass ejections

2008 ◽  
Vol 4 (S257) ◽  
pp. 271-277
Author(s):  
Bojan Vršnak ◽  
Dijana Vrbanec ◽  
Jaša Čalogović ◽  
Tomislav Žic
Keyword(s):  
Solar Wind ◽  
Wind Speed ◽  
Coronal Mass Ejections ◽  
Weather Forecasting ◽  
Aerodynamic Drag ◽  
Interplanetary Space ◽  
Solar Wind Speed ◽  
Standard Form ◽  
The Sun

AbstractDynamics of coronal mass ejections (CMEs) is strongly affected by the interaction of the erupting structure with the ambient magnetoplasma: eruptions that are faster than solar wind transfer the momentum and energy to the wind and generally decelerate, whereas slower ones gain the momentum and accelerate. Such a behavior can be expressed in terms of “aerodynamic” drag. We employ a large sample of CMEs to analyze the relationship between kinematics of CMEs and drag-related parameters, such as ambient solar wind speed and the CME mass. Employing coronagraphic observations it is demonstrated that massive CMEs are less affected by the aerodynamic drag than light ones. On the other hand, in situ measurements are used to inspect the role of the solar wind speed and it is shown that the Sun-Earth transit time is more closely related to the wind speed than to take-off speed of CMEs. These findings are interpreted by analyzing solutions of a simple equation of motion based on the standard form for the drag acceleration. The results show that most of the acceleration/deceleration of CMEs on their way through the interplanetary space takes place close to the Sun, where the ambient plasma density is still high. Implications for the space weather forecasting of CME arrival-times are discussed.

scholarly journals Configuration of a Magnetic Cloud From Solar Orbiter and Wind Spacecraft In-situ Measurements

2021 ◽  
Vol 9 ◽  
Author(s):  
Qiang Hu ◽  
Wen He ◽  
Lingling Zhao ◽  
Edward Lu
Keyword(s):  
Magnetic Field ◽  
Three Dimensional ◽  
Flux Rope ◽  
3D Models ◽  
Field Configuration ◽  
Magnetic Clouds ◽  
Physical Parameters ◽  
The Sun ◽  
Wind Spacecraft

Coronal mass ejections (CMEs) represent one type of the major eruption from the Sun. Their interplanetary counterparts, the interplanetary CMEs (ICMEs), are the direct manifestations of these structures when they propagate into the heliosphere and encounter one or more observing spacecraft. The ICMEs generally exhibit a set of distinctive signatures from the in-situ spacecraft measurements. A particular subset of ICMEs, the so-called Magnetic Clouds (MCs), is more uniquely defined and has been studied for decades, based on in-situ magnetic field and plasma measurements. By utilizing the latest multiple spacecraft measurements and analysis tools, we report a detailed study of the internal magnetic field configuration of an MC event observed by both the Solar Orbiter (SO) and Wind spacecraft in the solar wind near the Sun-Earth line. Both two-dimensional (2D) and three-dimensional (3D) models are applied to reveal the flux rope configurations of the MC. Various geometrical as well as physical parameters are derived and found to be similar within error estimates for the two methods. These results quantitatively characterize the coherent MC flux rope structure crossed by the two spacecraft along different paths. The implication for the radial evolution of this MC event is also discussed.

Numerical Simulation on the Propagation and Deflection of Fast Coronal Mass Ejections (CMEs) Interacting with a Corotating Interaction Region in Interplanetary Space

2020 ◽  
Author(s):  
Fang Shen ◽  
Yousheng Liu ◽  
Yi Yang
Keyword(s):  
Solar Wind ◽  
Coronal Mass Ejections ◽  
Interplanetary Space ◽  
Three Dimensional ◽  
Flux Rope ◽  
Interaction Region ◽  
The Sun ◽  
Corotating Interaction Region ◽  
The Common ◽  
Wind Flows

<p>Previous research has shown that the deflection of coronal mass ejections (CMEs) in interplanetary space, especially fast CMEs, is a common phenomenon. The deflection caused by the interaction with background solar wind is an important factor to determine whether CMEs could hit Earth or not. As the Sun rotates, there will be interactions between solar wind flows with different speeds. When faster solar wind runs into slower solar wind<br>ahead, it will form a compressive area corotating with the Sun, which is called a corotating interaction region (CIR). These compression regions always have a higher density than the common background solar wind. When interacting with CME, will this make a difference in the deflection process of CME? In this research, first, a three-dimensional (3D) flux-rope CME initialization model is established based on the graduated cylindrical shell (GCS)<br>model. Then this CME model is introduced into the background solar wind, which is obtained using a 3D IN (INterplanetary) -TVD-MHD model. The Carrington Rotation (CR) 2154 is selected as an example to simulate the propagation and deflection of fast CME when it interacts with background solar wind, especially with the CIR structure.</p><p>The simulation results show that: (1) the fast CME will deflect eastward when it propagates into the background solar wind without the CIR; (2) when the fast CME hits the CIR on its west side, it will also deflect eastward, and the deflection angle will increase compared with the situation without CIR.</p>

scholarly journals Influence of coronal mass ejections on parameters of high-speed solar wind: a case study

2018 ◽  
Vol 8 ◽  
pp. A28 ◽  
Author(s):  
Yulia Shugay ◽  
Vladimir Slemzin ◽  
Denis Rodkin ◽  
Yuri Yermolaev ◽  
Igor Veselovsky
Keyword(s):  
Solar Wind ◽  
Coronal Mass Ejections ◽  
High Speed ◽  
The Sun ◽  
The Earth ◽  
Speed Solar Wind ◽  
Measured Speed ◽  
Semi Empirical ◽  
High Speed Solar Wind

We investigate the case of disagreement between predicted and observed in-situ parameters of the recurrent high-speed solar wind streams (HSSs) existing for Carrington rotation (CR) 2118 (December 2011) in comparison with CRs 2117 and 2119. The HSSs originated at the Sun from a recurrent polar coronal hole (CH) expanding to mid-latitudes, and its area in the central part of the solar disk increased with the rotation number. This part of the CH was responsible for the equatorial flank of the HSS directed to the Earth. The time and speed of arrival for this part of the HSS to the Earth were predicted by the hierarchical empirical model based on EUV-imaging and the Wang-Sheeley-Arge ENLIL semi-empirical replace  model and compared with the parameters measured in-situ by model. The predicted parameters were compared with those measured in-situ. It was found, that for CR 2117 and CR 2119, the predicted HSS speed values agreed with the measured ones within the typical accuracy of ±100 km s−1. During CR 2118, the measured speed was on 217 km s−1 less than the value predicted in accordance with the increased area of the CH. We suppose that at CR 2118, the HSS overtook and interacted with complex ejecta formed from three merged coronal mass ejections (CMEs) with a mean speed about 400 km s−1. According to simulations of the Drag-based model, this complex ejecta might be created by several CMEs starting from the Sun in the period between 25 and 27 December 2011 and arriving to the Earth simultaneously with the HSS. Due to its higher density and magnetic field strength, the complex ejecta became an obstacle for the equatorial flank of the HSS and slowed it down. During CR 2117 and CR 2119, the CMEs appeared before the arrival of the HSSs, so the CMEs did not influence on the HSSs kinematics.

scholarly journals Flows and obstacles in the heliosphere

2008 ◽  
Vol 4 (S257) ◽  
pp. 577-587 ◽  
Author(s):  
John D. Richardson
Keyword(s):  
Solar Wind ◽  
Interstellar Medium ◽  
Time Scales ◽  
Coronal Mass Ejections ◽  
Termination Shock ◽  
Shock Structure ◽  
The Sun ◽  
Interplanetary Coronal Mass Ejections ◽  
Shock Heating

AbstractThe supersonic solar wind is highly variable on all time scales near the Sun but fluctuations are moderated by self-interaction as this plasma moves outward. The solar wind runs into many obstacles on its way out. The neutrals from the interstellar medium slow it down. Magnetospheres and interplanetary coronal mass ejections (ICMEs) cause shocks to form so that the flow can divert around these obstacles. Finally the solar wind is stopped by the circum-heliospheric interstellar medium (CHISM); it slows at the termination shock and then turns down the heliotail. The shocks and sheaths formed by these interactions cover scales which vary by orders of magnitude; some aspects of these shocks and sheaths look very similar and some very different. We discuss solar wind evolution, interaction with the neutrals from the CHISM, foreshocks, shock structure, shock heating, asymmetries, and sheath variability in different sheath regions.

scholarly journals Shock deceleration in interplanetary coronal mass ejections (ICMEs) beyond Mercury’s orbit until one AU

2018 ◽  
Vol 8 ◽  
pp. A54 ◽  
Author(s):  
Benjamin Grison ◽  
Jan Souček ◽  
Vratislav Krupar ◽  
David Píša ◽  
Ondrej Santolík ◽  
...  
Keyword(s):  
Coronal Mass Ejections ◽  
The Sun ◽  
Interplanetary Shocks ◽  
Interplanetary Coronal Mass Ejections ◽  
Large Dataset ◽  
Arrival Times ◽  
The Earth ◽  
Average Accuracy ◽  
Shock Fronts

The CDPP propagation tool is used to propagate interplanetary coronal mass ejections (ICMEs) observed at Mercury by MESSENGER to various targets in the inner solar system (VEX, ACE, STEREO-A and B). The deceleration of ICME shock fronts between the orbit of Mercury and 1 AU is studied on the basis of a large dataset. We focus on the interplanetary medium far from the solor corona, to avoid the region where ICME propagation modifications in velocity and direction are the most drastic. Starting with a catalog of 61 ICMEs recorded by MESSENGER, the propagation tool predicts 36 ICME impacts with targets. ICME in situ signatures are investigated close to predicted encounter times based on velocities estimated at MESSENGER and on the default propagation tool velocity (500 km s−1). ICMEs are observed at the targets in 26 cases and interplanetary shocks (not followed by magnetic ejecta) in two cases. Comparing transit velocities between the Sun and MESSENGER ($ {\bar{v}}_{\mathrm{SunMess}}$) and between MESSENGER and the targets ($ {\bar{v}}_{\mathrm{MessTar}}$), we find an average deceleration of 170 km s−1 (28 cases). Comparing $ {\bar{v}}_{\mathrm{MessTar}}$ to the velocities at the targets (v Tar), average ICME deceleration is about 160 km s−1 (13 cases). Our results show that the ICME shock deceleration is significant beyond Mercury’s orbit. ICME shock arrival times are predicted with an average accuracy of about six hours with a standard deviation of eleven hours. Focusing on two ICMEs detected first at MESSENGER and later on by two targets illustrates our results and the variability in ICME propagations. The shock velocity of an ICME observed at MESSENGER, then at VEX and finally at STEREO-B decreases all the way. Predicting arrivals of potentially effective ICMEs is an important space weather issue. The CDPP propagation tool, in association with in situ measurements between the Sun and the Earth, can permit to update alert status of such arrivals.

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