Transit times of interplanetary coronal mass ejections and the solar wind speed

Vršnak, Bojan; Žic, Tomislav

doi:10.1051/0004-6361:20077499

Cited by 118 publications

(114 citation statements)

References 49 publications

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“…Thus, the shortest transit times can be achieved only by fast, massive, and relatively narrow CMEs (implying also high densities), especially when propagating in high speed solar wind streams of low density. The described behavior is fully consistent with the empirical relationships reported by Vršnak & Žic (2007) and Vršnak et al (2008).…”

Section: Kinematicssupporting

confidence: 88%

“…For this purpose, various forecasting methods were developed based either on the empirical/statistical relationships (e.g. Gopalswamy et al 2000;Michałek et al 2004;Vršnak & Žic 2007), analytical propagation models (e.g. Smart & Shea 1985;Vršnak & Gopalswamy 2002;Cantó et al 2005;Vršnak & Žic 2007;Borgazzi et al 2009;), or numerical MHD simulations (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Gopalswamy et al 2000;Michałek et al 2004;Vršnak & Žic 2007), analytical propagation models (e.g. Smart & Shea 1985;Vršnak & Gopalswamy 2002;Cantó et al 2005;Vršnak & Žic 2007;Borgazzi et al 2009;), or numerical MHD simulations (e.g. González-Esparza et al 2003;Manchester et al 2004;Odstrcil et al 2004;Smith et al 2009;Taktakishvili et al 2009).…”

Section: Introductionmentioning

confidence: 99%

“…Gopalswamy et al 2000Gopalswamy et al , 2001Vršnak & Gopalswamy 2002;Yashiro et al 2004;Tappin 2006;Manoharan 2006;Vršnak & Žic 2007;Vršnak et al 2008). Taking into account the physical properties of the drag (e.g.…”

Section: Introductionmentioning

confidence: 99%

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The role of aerodynamic drag in propagation of interplanetary coronal mass ejections

Vršnak

Žic

Falkenberg

et al. 2010

A&A

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122

115

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Context. The propagation of interplanetary coronal mass ejections (ICMEs) and the forecast of their arrival on Earth is one of the central issues of space weather studies. Aims. We investigate to which degree various ICME parameters (mass, size, take-off speed) and the ambient solar-wind parameters (density and velocity) affect the ICME Sun-Earth transit time. Methods. We study solutions of a drag-based equation of motion by systematically varying the input parameters. The analysis is focused on ICME transit times and 1 AU velocities. Results. The model results reveal that wide ICMEs of low masses adjust to the solar-wind speed already close to the sun, so the transit time is determined primarily by the solar-wind speed. The shortest transit times and accordingly the highest 1 AU velocities are related to narrow and massive ICMEs (i.e. high-density eruptions) propagating in high-speed solar wind streams. We apply the model to the Sun-Earth event associated with the CME of 25 July 2004 and compare the results with the outcome of the numerical MHD modeling.

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Section: Kinematicssupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The role of aerodynamic drag in propagation of interplanetary coronal mass ejections

Vršnak

Žic

Falkenberg

et al. 2010

A&A

Self Cite

122

115

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“…The methodology applied in these works consists on the establishment of relationships between the observed data, i.e., the CME initial speed; speeds observed in the interplanetary medium; and the mean acceleration acting on the ICMEs. The studies reported by Vršnak (2001); Vršnak et al (2002Vršnak et al ( , 2004Vršnak et al ( , 2007 may be considered in the same branch, with the difference that in these cases the studies are done, from the point of view of viscous forces acting on the ICMEs. The group of numerical simulation of the transport of ICMEs is more numerous (e.g.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of coronal mass ejections in the interplanetary medium

Borgazzi¹,

Lara²,

Echer³

et al. 2009

A&A

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Context. Coronal mass ejections (CMEs) are large plasma structures expelled from the low corona to the interplanetary space with a wide range of speeds. In the interplanetary medium CMEs suffer changes in their speeds because of interaction with the ambient solar wind. Aims. To understand the interplanetary CME (ICME) dynamics, we analyze the interaction between these structures and the ambient solar wind (SW), approaching the problem from the hydrodynamic point of view. Methods. We assume that the dynamics of the system is dominated by two kinds of drag-force dependence on speed (U), as ∼U and ∼U 2 . Furthermore, we propose a model that takes variations of the ICME radius (R) and SW density (ρ sw ) into account as a function of the distance (x) as R(x) = x 0.78 and ρ sw (x) = 1/x 2 , respectively. Then, we solve the equation of motion and present exact solutions Results. Considering CME speeds measured at a few solar radii and at one AU, we were able to constrain the values of the constants (viscosity and drag coefficient) for the linear (U) and quadratic (U 2 ) speed dependences, which seems to reproduce the ICME -SW system well. We found different solutions in which the concavity of the curves of the ICME speed profile changes, depending on the dominant factor, either the ICME radius or the SW density. Conclusions. This work shows that the macroscopic ICME propagation may be described by the hydrodynamic theory and that it is possible to find analytical solutions for the ICME-SW interaction.

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Full halo coronal mass ejections: Do we need to correct the projection effect in terms of velocity?

et al. 2013

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[1] The projection effect is one of the biggest obstacles in learning the real properties of coronal mass ejections (CMEs) and forecasting their geoeffectiveness. To evaluate the projection effect, 86 full halo CMEs (FHCMEs) listed in the Coordinated Data Analysis Workshop CME catalog from 1 March 2007 to 31 May 2012 are investigated. By applying the Graduated Cylindrical Shell model, we obtain the deprojected values of the propagation velocity, direction, and angular width of these FHCMEs and compare them with the projected values measured in the plane-of-sky. Although these CMEs look full halo in the view angle of SOHO, it is found that their propagation directions and angular widths could vary in a large range, implying projection effect is a major reason causing a CME being halo, but not the only one. Furthermore, the comparison of the deprojected and projected velocities reveals that most FHCMEs originating within 45 ı of the Sun-Earth line with a projected speed slower than 900 km s -1 suffer from large projection effect, while the FHCMEs originating far from the vicinity of solar disk center or moving faster than 900 km s -1 have small projection effect. Thus, for the latter class of FHCMEs, it is not necessary to correct the measured velocities.

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Transit times of interplanetary coronal mass ejections and the solar wind speed

Cited by 118 publications

References 49 publications

The role of aerodynamic drag in propagation of interplanetary coronal mass ejections

The role of aerodynamic drag in propagation of interplanetary coronal mass ejections

Dynamics of coronal mass ejections in the interplanetary medium

Full halo coronal mass ejections: Do we need to correct the projection effect in terms of velocity?

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