scholarly journals Dynamics of the field-aligned currents distribution asymmetry during substorms in the equinox season

2021 ◽  
Vol 7 (1) ◽  
pp. 40-50
Author(s):  
Vladimir Mishin ◽  
Vilen Mishin ◽  
Marina Kurikalova
Keyword(s):  
Pressure Pulse ◽  
Wind Pressure ◽  
Physical Processes ◽  
Polar Cap ◽  
Azimuthal Component ◽  
Seasonal Behavior ◽  
Summer Hemisphere ◽  
Solar Wind Pressure ◽  
Winter Hemisphere

We continue to study the physical processes occurring during the August 17, 2001 magnetospheric storm by analyzing the dynamics of the intensity of field-aligned currents (FACs) in Iijima—Potemra Region 1 in the polar ionospheres of two hemispheres, using the modernized magnetogram inversion technique. The results obtained on the dynamics of the FAC asymmetry of two types (dawn–dusk and interhemispheric), as well as the previously obtained regularities in the behavior of Hall currents and polar cap boundaries depending on the large azimuthal component of the interplanetary magnetic field (IMF), observed during the storm, and the seasonal behavior of the conductivity are consistent with the open magnetosphere model and with satellite observations of auroras in two hemispheres. We have shown that the weakening of the asymmetry of two types in the FAC distribution during substorms in the storm under study occurs almost completely in the winter hemisphere and is much weaker in the summer one. We associate this phenomenon with the predominance of the effect of long-term exposure to the azimuthal IMF component in the sunlit polar ionosphere of the summer hemisphere over the substorm symmetrization effect of the night magnetosphere. A symmetrization effect of the polar cap and FACs, created by the solar wind pressure pulse at the end of the storm, is observed. We propose a qualitative explanation of this effect.

scholarly journals Dynamics of the field-aligned currents distribution asymmetry during substorms in the equinox season

2021 ◽  
Vol 7 (1) ◽  
pp. 32-40
Author(s):  
Vladimir Mishin ◽  
Vilen Mishin ◽  
Marina Kurikalova
Keyword(s):  
Pressure Pulse ◽  
Wind Pressure ◽  
Physical Processes ◽  
Polar Cap ◽  
Azimuthal Component ◽  
Seasonal Behavior ◽  
Summer Hemisphere ◽  
Solar Wind Pressure ◽  
Winter Hemisphere

We continue to study the physical processes occurring during the August 17, 2001 magnetospheric storm by analyzing the dynamics of the intensity of field-aligned currents (FACs) in Iijima—Potemra Region 1 in the polar ionospheres of two hemispheres, using the modernized magnetogram inversion technique. The results obtained on the dynamics of the FAC asymmetry of two types (dawn–dusk and interhemispheric), as well as the previously obtained regularities in the behavior of Hall currents and polar cap boundaries depending on the large azimuthal component of the interplanetary magnetic field (IMF), observed during the storm, and the seasonal behavior of the conductivity are consistent with the open magnetosphere model and with satellite observations of auroras in two hemispheres. We have shown that the weakening of the asymmetry of two types in the FAC distribution during substorms in the storm under study occurs almost completely in the winter hemisphere and is much weaker in the summer one. We associate this phenomenon with the predominance of the effect of long-term exposure to the azimuthal IMF component in the sunlit polar ionosphere of the summer hemisphere over the substorm symmetrization effect of the night magnetosphere. A symmetrization effect of the polar cap and FACs, created by the solar wind pressure pulse at the end of the storm, is observed. We propose a qualitative explanation of this effect.

scholarly journals Dynamics of field-aligned currents in two hemispheres during a magnetospheric storm from magnetogram inversion technique data

2021 ◽  
Vol 7 (1) ◽  
pp. 27-31
Author(s):  
Vladimir Mishin ◽  
Yuriy Karavaev ◽  
Sergey Lunyushkin ◽  
Yury Penskikh ◽  
Vyacheslav Kapustin
Keyword(s):  
Wind Pressure ◽  
Physical Processes ◽  
Polar Cap ◽  
Azimuthal Component ◽  
Seasonal Behavior ◽  
Inversion Technique ◽  
Summer Hemisphere ◽  
Solar Wind Pressure ◽  
Winter Hemisphere

We continue to study the physical processes occurring during the August 17, 2001 magnetospheric storm by analyzing the dynamics of the intensity of field-aligned currents (FACs) in Iijima—Potemra Region 1 in the polar ionospheres of the two hemispheres, using the modernized magnetogram inversion technique. The results obtained on the dynamics of two types of FAC asymmetry (dawn-dusk and interhemispheric), as well as the previously obtained regularities in the behavior of Hall currents and the polar cap boundaries depending on the large azimuthal component of the interplanetary magnetic field (IMF), observed during the storm, and the seasonal behavior of the conductivity are consistent with the open magnetosphere model and with satellite observations of auroras in two hemispheres. We have shown that the weakening of the asymmetry of two types in the FAC distribution during substorms in the storm under study occurs almost completely in the winter hemisphere and is much weaker in the summer one. We associate this phenomenon with the predominance of the effect of long-term exposure to the azimuthal IMF component in the sunlit polar ionosphere of the summer hemisphere over the substorm symmetrization effect of the night magnetosphere. A symmetrization effect of the polar cap and FACs, created by the solar wind pressure pulse at the end of the storm, is observed. We propose a qualitative explanation of this effect.

scholarly journals Dynamics of field-aligned currents in two hemispheres during a magnetospheric storm from magnetogram inversion technique data

2021 ◽  
Vol 7 (1) ◽  
pp. 34-39
Author(s):  
Vladimir Mishin ◽  
Yuriy Karavaev ◽  
Sergey Lunyushkin ◽  
Yury Penskikh ◽  
Vyacheslav Kapustin
Keyword(s):  
Wind Pressure ◽  
Physical Processes ◽  
Polar Cap ◽  
Azimuthal Component ◽  
Seasonal Behavior ◽  
Inversion Technique ◽  
Summer Hemisphere ◽  
Solar Wind Pressure ◽  
Winter Hemisphere

We continue to study the physical processes occurring during the August 17, 2001 magnetospheric storm by analyzing the dynamics of the intensity of field-aligned currents (FACs) in Iijima—Potemra Region 1 in the polar ionospheres of the two hemispheres, using the modernized magnetogram inversion technique. The results obtained on the dynamics of two types of FAC asymmetry (dawn-dusk and interhemispheric), as well as the previously obtained regularities in the behavior of Hall currents and the polar cap boundaries depending on the large azimuthal component of the interplanetary magnetic field (IMF), observed during the storm, and the seasonal behavior of the conductivity are consistent with the open magnetosphere model and with satellite observations of auroras in two hemispheres. We have shown that the weakening of the asymmetry of two types in the FAC distribution during substorms in the storm under study occurs almost completely in the winter hemisphere and is much weaker in the summer one. We associate this phenomenon with the predominance of the effect of long-term exposure to the azimuthal IMF component in the sunlit polar ionosphere of the summer hemisphere over the substorm symmetrization effect of the night magnetosphere. A symmetrization effect of the polar cap and FACs, created by the solar wind pressure pulse at the end of the storm, is observed. We propose a qualitative explanation of this effect.

scholarly journals Solar wind and substorm excitation of the wavy current sheet

2009 ◽  
Vol 27 (6) ◽  
pp. 2457-2474 ◽  
Author(s):  
C. Forsyth ◽  
M. Lester ◽  
R. C. Fear ◽  
E. Lucek ◽  
I. Dandouras ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Current Sheet ◽  
Pressure Pulse ◽  
Wind Pressure ◽  
Expansion Velocity ◽  
Solar Wind Pressure ◽  
Wave Models ◽  
Best Fit ◽  
The Magnetic Field

Abstract. Following a solar wind pressure pulse on 3 August 2001, GOES 8, GOES 10, Cluster and Polar observed dipolarizations of the magnetic field, accompanied by an eastward expansion of the aurora observed by IMAGE, indicating the occurrence of two substorms. Prior to the first substorm, the motion of the plasma sheet with respect to Cluster was in the ZGSM direction. Observations following the substorms show the occurrence of current sheet waves moving predominantly in the −YGSM direction. Following the second substorm, the current sheet waves caused multiple current sheet crossings of the Cluster spacecraft, previously studied by Zhang et al. (2002). We further this study to show that the velocity of the current sheet waves was similar to the expansion velocity of the substorm aurora and the expansion of the dipolarization regions in the magnetotail. Furthermore, we compare these results with the current sheet wave models of Golovchanskaya and Maltsev (2005) and Erkaev et al. (2008). We find that the Erkaev et al. (2008) model gives the best fit to the observations.

scholarly journals Rosetta and Mars Express observations of the influence of high solar wind pressure on the Martian plasma environment

2009 ◽  
Vol 27 (12) ◽  
pp. 4533-4545 ◽  
Author(s):  
N. J. T. Edberg ◽  
U. Auster ◽  
S. Barabash ◽  
A. Bößwetter ◽  
D. A. Brain ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Pressure ◽  
Solar Wind ◽  
Pressure Pulse ◽  
Wind Pressure ◽  
Data Set ◽  
Mars Express ◽  
Boundary Crossings ◽  
Plasma Environment ◽  
Solar Wind Pressure

Abstract. We report on new simultaneous in-situ observations at Mars from Rosetta and Mars Express (MEX) on how the Martian plasma environment is affected by high pressure solar wind. A significant sharp increase in solar wind density, magnetic field strength and turbulence followed by a gradual increase in solar wind velocity is observed during ~24 h in the combined data set from both spacecraft after Rosetta's closest approach to Mars on 25 February 2007. The bow shock and magnetic pileup boundary are coincidently observed by MEX to become asymmetric in their shapes. The fortunate orbit of MEX at this time allows a study of the inbound boundary crossings on one side of the planet and the outbound crossings on almost the opposite side, both very close to the terminator plane. The solar wind and interplanetary magnetic field (IMF) downstream of Mars are monitored through simultaneous measurements provided by Rosetta. Possible explanations for the asymmetries are discussed, such as crustal magnetic fields and IMF direction. In the same interval, during the high solar wind pressure pulse, MEX observations show an increased amount of escaping planetary ions from the polar region of Mars. We link the high pressure solar wind with the observed simultaneous ion outflow and discuss how the pressure pulse could also be associated with the observed boundary shape asymmetry.

Observations of solar wind pressure initiated fast mode waves at geostationary orbit and in the polar cap

1991 ◽  
Vol 53 (3-4) ◽  
pp. 231-239 ◽  
Author(s):  
R.E. Erlandson ◽  
D.G. Sibeck ◽  
R.E. Lopez ◽  
L.J. Zanetti ◽  
T.A. Potemra
Keyword(s):  
Solar Wind ◽  
Wind Pressure ◽  
Geostationary Orbit ◽  
Fast Mode ◽  
Polar Cap ◽  
Solar Wind Pressure

scholarly journals Solar wind pressure pulse-driven magnetospheric vortices and their global consequences

2014 ◽  
Vol 119 (6) ◽  
pp. 4274-4280 ◽  
Author(s):  
Q. Q. Shi ◽  
M.D. Hartinger ◽  
V. Angelopoulos ◽  
A.M. Tian ◽  
S.Y. Fu ◽  
...  
Keyword(s):  
Solar Wind ◽  
Pressure Pulse ◽  
Wind Pressure ◽  
Solar Wind Pressure

scholarly journals Localized ion outflow in response to a solar wind pressure pulse

2002 ◽  
Vol 107 (A8) ◽  
pp. SMP 26-1-SMP 26-9 ◽  
Author(s):  
S. A. Fuselier ◽  
H. L. Collin ◽  
A. G. Ghielmetti ◽  
E. S. Claflin ◽  
T. E. Moore ◽  
...  
Keyword(s):  
Solar Wind ◽  
Pressure Pulse ◽  
Wind Pressure ◽  
Ion Outflow ◽  
Solar Wind Pressure

scholarly journals SWMF simulation of field-aligned currents for a varying northward and duskward IMF with nonzero dipole tilt

2008 ◽  
Vol 26 (6) ◽  
pp. 1461-1477 ◽  
Author(s):  
H. Wang ◽  
A. J. Ridley ◽  
H. Lühr
Keyword(s):  
Open Field ◽  
Hemispheric Asymmetry ◽  
Closed Field ◽  
Polar Cap ◽  
Counterclockwise Rotation ◽  
Summer Hemisphere ◽  
Field Lines ◽  
Winter Hemisphere ◽  
Dipole Tilt ◽  
The Imf

Abstract. This study concentrates on the FACs distribution for the varying northward and duskward interplanetary magnetic field (IMF) conditions when the dipole tilt is nonzero. A global MHD simulation (the Space Weather Modeling Framework, SWMF) has been used to perform this study. Hemispheric asymmetry of the time evolution of northward IMF Bz (NBZ) FACs is found. As the IMF changes from strictly northward to duskward, NBZ FACs shift counterclockwise in both summer and winter hemispheres. However, in the winter hemisphere, the counterclockwise rotation prohibits the duskward NBZ FACs from evolving into the midday R1 FACs. The midday R1 FACs seem to be an intrusion of dawnside R1 FACs. In the summer hemisphere, the NBZ FACs can evolve into the DPY FACs, consisting of the midday R0 and R1 FACs, after the counterclockwise rotation. The hemispheric asymmetry is due to the fact that the dipole tilt favors more reconnection between the IMF and the summer magnetosphere. When mapping the NBZ and DPY FACs into the magnetosphere it is found that the NBZ currents are located on both open and closed field lines, irrespective of the IMF direction. For the DPY FACs the hemispheric asymmetry emerges: the midday R1 FACs and a small part of R0 FACs are on closed field lines in the winter hemisphere, while a small part of the midday R1 FACs and all the R0 FACs are on open field lines in the summer hemisphere. Both IMF By and dipole tilt cause the polar cap hemispheric and local time asymmetric. When the IMF is northward, the summer polar cap is closed on the nightside while the winter polar cap is open. The polar cap boundary tends to move equatorward as the IMF rotates from northward to duskward, except in the summer hemisphere, the polar cap on the dawnside shifts poleward when the clock angle is less than 10°. The further poleward displacement of the polar cap boundary on one oval side is caused by the twist of the tail plasma sheet, which is in accordance with the changing open field lines topology in the magnetotail.

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