Investigation of the magnetic field between the shock wave and the obstacle in the solar wind flow around a planet

Knowledge about the magnetic field and plasma environment is important for almost all physical processes in the solar atmosphere. Precise measurements of the magnetic field vector are done routinely only in the photosphere, e.g. by SDO/HMI. These measurements are used as boundary condition for modelling the solar chromosphere and corona, whereas some model assumptions have to be made. In the low-plasma-beta corona the Lorentz-force vanishes and the magnetic field is reconstructed with a nonlinear force-free model. In the mixed-beta chromosphere plasma forces have to be taken into account with the help of a magnetostatic model. And finally for modelling the global corona far beyond the source surface the solar wind flow has to be incorporated within a stationary MHD model. To do so, we generalize a nonlinear force-free and magneto-static optimization code by the inclusion of a field aligned compressible plasma flow. Applications are the implementation of the solar wind on global scale. This allows to reconstruct the coronal magnetic field further outwards than with potential field, nonlinear force-free and magneto-static models. This way the model might help in future to provide the magnetic connectivity for joint observations of remote sensing and in-situ instruments on Solar Orbiter and Parker Solar Probe.

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Waves in the magnetic field and solar wind flow outside the bow shock at comet P/Halley

Exploration of Halley’s Comet ◽

10.1007/978-3-642-82971-0_7 ◽

1988 ◽

pp. 47-54 ◽

Cited By ~ 1

Author(s):

A. Johnstone ◽

K. Glassmeier ◽

M. Acuna ◽

H. Borg ◽

D. Bryant ◽

...

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Bow Shock ◽

Wind Flow ◽

Solar Wind Flow ◽

The Magnetic Field

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On the Geoeffectiveness Structure of Solar Wind-Magnetosphere Coupling Functions during Intense Storms

ISRN Astronomy and Astrophysics ◽

10.5402/2011/961757 ◽

2011 ◽

Vol 2011 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

B. Olufemi Adebesin ◽

S. Oluwole Ikubanni ◽

J. Stephen Kayode

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Magnetic Cloud ◽

Recovery Phase ◽

Flow Speed ◽

Event Correlation ◽

Phase Duration ◽

Event Identification ◽

Solar Wind Flow ◽

The Magnetic Field

The geoeffectiveness of some coupling functions for the Solar Wind-Magnetosphere Interaction had been studied. 58 storms with peak Dst < −100 nT were used. The result showed that the interplanetary magnetic field Bz appeared to be more relevant with the magnetic field B (which agreed with previous results). However, both the V (solar wind flow speed) and Bz factors in the interplanetary dawn-dusk electric field (V×Bz) are effective in the generation of very intense storms (peak Dst < −250 nT) while “intense” storms (−250 nT ≤ peak Dst < −100 nT) are mostly enhanced by the Bz factor alone (in most cases). The southward Bz duration BT seems to be more relevant for Dst < −250 nT class of storms and invariably determines the recovery phase duration. Most of the storms were observed to occur at midnight hours (i.e., 2100–0400 UT), having a 41.2% incidence rate, with high frequency between 2300 UT and 0000 UT. 62% of the events were generated as a result of Magnetic Cloud (MC), while 38% were generated by complex ejecta. The B-Bz relation for the magnetic cloud attained a correlation coefficient of 0.8922, while it is 0.7608 for the latter. Conclusively, Bz appears to be the most geoeffective factor, and geoeffectiveness should be a factor that depends on methods of event identification and classification as well as the direction of event correlation.

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MHD effects of the solar wind flow around planets

Nonlinear Processes in Geophysics ◽

10.5194/npg-7-201-2000 ◽

2000 ◽

Vol 7 (3/4) ◽

pp. 201-210 ◽

Cited By ~ 2

Author(s):

H. K. Biernat ◽

N. V. Erkaev ◽

C. J. Farrugia ◽

D. F. Vogl ◽

W. Schaffenberger

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Mach Number ◽

Boundary Conditions ◽

Wind Flow ◽

Magnetic Shear ◽

Thermal Anisotropy ◽

Terrestrial Magnetosphere ◽

Solar Wind Flow

Abstract. The study of the interaction of the solar wind with magnetized and unmagnetized planets forms a central topic of space research. Focussing on planetary magnetosheaths, we review some major developments in this field. Magnetosheath structures depend crucially on the orientation of the interplanetary magnetic field, the solar wind Alfvén Mach number, the shape of the obstacle (axisymmetric/non-axisymmetric, etc.), the boundary conditions at the magnetopause (low/high magnetic shear), and the degree of thermal anisotropy of the plasma. We illustrate the cases of Earth, Jupiter and Venus. The terrestrial magnetosphere is axisymmetric and has been probed in-situ by many spacecraft. Jupiter's magnetosphere is highly non-axisymmetric. Furthermore, we study magnetohydrodynamic effects in the Venus magnetosheath.

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Influence of the Interplanetary Magnetic Field on the Solar Wind Flow about Planetary Obstacles

Space Science Reviews ◽

10.1007/s11214-006-6059-z ◽

2006 ◽

Vol 122 (1-4) ◽

pp. 209-219 ◽

Cited By ~ 5

Author(s):

Nikolai Erkaev ◽

Alexander Mezentsev ◽

Helfried Biernat

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Interplanetary Magnetic Field ◽

Wind Flow ◽

Solar Wind Flow

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Occurrence rate of magnetic holes between 0.72 and 1 AU: comparative study of Cluster and VEX data

Annales Geophysicae ◽

10.5194/angeo-29-717-2011 ◽

2011 ◽

Vol 29 (5) ◽

pp. 717-722 ◽

Cited By ~ 8

Author(s):

O. A. Amariutei ◽

S. N. Walker ◽

T. L. Zhang

Keyword(s):

Solar Wind ◽

Occurrence Rate ◽

Wind Flow ◽

The Sun ◽

Common Features ◽

The Earth ◽

Magnetic Field Magnitude ◽

Solar Wind Flow ◽

Stable Plasma ◽

The Magnetic Field

Abstract. Localised depressions in the magnetic field magnitude, or magnetic holes, are common features in many regions of solar system plasma. Two distinct mechanisms for their generation have been proposed. The first proposed that the structures are generated locally, close to the point of observation. The alternative has been proposed by Russell et al. (2008), who suggest that the observed magnetic holes represent nonlinear mirror structures that can be carried by the solar wind over vast distances of mirror stable plasma. According to Russell et al. (2008), magnetic holes are created in the vicinity of the sun and are convected by the solar wind outward. Periods of Cluster 1 and VEX data when both spacecraft were connected by the solar wind flow have been considered in this study, in order to determine the evolution of the magnetic holes occurrence rate. The comparison of the magnetic holes occurrence near the Venus and the Earth supports the Russell et al. (2008) premise that they are generated closer to the Sun most likely somewhere within the orbit of Mercury.

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Modelling the evolution of CMEs and their shocks through different solar wind structures

10.5194/egusphere-egu2020-11003 ◽

2020 ◽

Author(s):

Erika Palmerio ◽

Christina Lee ◽

Leila Mays ◽

Dusan Odstrcil

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Vantage Point ◽

Angular Width ◽

Wind Flow ◽

The Sun ◽

Ambient Wind ◽

Fast Wind ◽

Solar Wind Flow ◽

Ambient Solar Wind

The evolution of coronal mass ejections (CMEs) as they travel away from the Sun is one of the major issues in heliophysics and space weather. After erupting, CMEs propagate outwards through the background solar wind flow, which in turn may significantly affect CME evolution by means of e.g. acceleration, deflection, and/or rotation. In order to determine to which extent the ambient wind can alter the speed, trajectory, and orientation of a CME, we run a series of 3D magnetohydrodynamics simulations (using the coupled solar&#8211;heliospheric WSA&#8211;Enlil model) to conduct a multi-vantage point study of the radial and longitudinal evolution of CME structures as they propagate up to Earth&#8217;s (1 AU) and Mars&#8217; (1.5 AU) orbits. We explore a broad range of input CME parameters (initial radial speed, angular width) and ambient solar wind conditions (slow versus fast wind) to investigate the different evolutionary behaviours of CMEs and their driven shocks and sheath regions. To study the radial and longitudinal evolution for the modelled CME ejecta and shock events, we examine the resulting magnetic field and plasma time series at different heliocentric distances (0.5 AU, 1 AU, and 1.5 AU) and heliolongitudes (in 30&#176; increments). This work will help establish a set of expected CME behaviours at Earth&#8217;s and Mars&#8217; radial distances, which can be used for analysing real CME events.

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