scholarly journals Locating dayside magnetopause reconnection with exhaust ion distributions

2017 ◽  
Vol 122 (5) ◽  
pp. 5105-5113 ◽  
Author(s):  
J. M. Broll ◽  
S. A. Fuselier ◽  
K. J. Trattner
Keyword(s):  
Ion Distributions ◽  
Dayside Magnetopause ◽  
Magnetopause Reconnection

Hybrid-Vlasov modelling of three-dimensional dayside magnetopause reconnection

2021 ◽  
Author(s):  
Yann Pfau-Kempf ◽  
Minna Palmroth ◽  
Andreas Johlander ◽  
Lucile Turc ◽  
Markku Alho ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Reconnection ◽  
Three Dimensional ◽  
Meridional Plane ◽  
Kinetic Behavior ◽  
Dayside Magnetopause ◽  
Field Junction ◽  
First Time ◽  
Kinetic Instabilities ◽  
Magnetopause Reconnection

<p>Dayside magnetic reconnection at the magnetopause, which is a major driver of space weather, is studied for the first time in a three-dimensional (3D) realistic setup using the Vlasiator hybrid-Vlasov kinetic model. A noon–midnight meridional plane simulation is extended in the dawn–dusk direction to cover 7 Earth radii. The southward interplanetary magnetic field causes magnetic reconnection to occur at the subsolar magnetopause. Perturbations arising from kinetic instabilities in the magnetosheath appear to modulate the reconnection. Its characteristics are consistent with multiple, bursty, and patchy magnetopause reconnection. It is shown that the kinetic behavior of the plasma, as simulated by the model, has consequences on the applicability of methods such as the four-field junction to identify and analyse magnetic reconnection in 3D kinetic simulations.</p>

scholarly journals A numerical model of the ionospheric signatures of time-varying magnetic reconnection: III. Quasi-instantaneous convection responses in the Cowley-Lockwood paradigm

2006 ◽  
Vol 24 (3) ◽  
pp. 961-972 ◽  
Author(s):  
S. K. Morley ◽  
M. Lockwood
Keyword(s):  
The Other ◽  
Closed Field ◽  
Time Varying ◽  
Residual Flow ◽  
Numerical Implementation ◽  
Ionospheric Convection ◽  
Dayside Magnetopause ◽  
History Of ◽  
Closed Field Line ◽  
Magnetopause Reconnection

Abstract. Using a numerical implementation of the cowlock92 model of flow excitation in the magnetosphere-ionosphere (MI) system, we show that both an expanding (on a ~12-min timescale) and a quasi-instantaneous response in ionospheric convection to the onset of magnetopause reconnection can be accommodated by the Cowley-Lockwood conceptual framework. This model has a key feature of time dependence, necessarily considering the history of the coupled MI system. We show that a residual flow, driven by prior magnetopause reconnection, can produce a quasi-instantaneous global ionospheric convection response; perturbations from an equilibrium state may also be present from tail reconnection, which will superpose constructively to give a similar effect. On the other hand, when the MI system is relatively free of pre-existing flow, we can most clearly see the expanding nature of the response. As the open-closed field line boundary will frequently be in motion from such prior reconnection (both at the dayside magnetopause and in the cross-tail current sheet), it is expected that there will usually be some level of combined response to dayside reconnection.

scholarly journals Dayside Magnetopause Reconnection: Its Dependence on Solar Wind and Magnetosheath Conditions

2019 ◽  
Vol 124 (11) ◽  
pp. 8778-8787
Author(s):  
D. Koga ◽  
W. D. Gonzalez ◽  
V. M. Souza ◽  
F. R. Cardoso ◽  
C. Wang ◽  
...  
Keyword(s):  
Solar Wind ◽  
Dayside Magnetopause ◽  
Magnetopause Reconnection

scholarly journals Evidence for transient, local ion foreshocks caused by dayside magnetopause reconnection

2016 ◽  
Vol 34 (11) ◽  
pp. 943-959 ◽  
Author(s):  
Yann Pfau-Kempf ◽  
Heli Hietala ◽  
Steve E. Milan ◽  
Liisa Juusola ◽  
Sanni Hoilijoki ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Ion Beams ◽  
Bow Shock ◽  
Flux Transfer Events ◽  
Dayside Magnetopause ◽  
Flux Transfer ◽  
Push Out ◽  
Magnetopause Reconnection

Abstract. We present a scenario resulting in time-dependent behaviour of the bow shock and transient, local ion reflection under unchanging solar wind conditions. Dayside magnetopause reconnection produces flux transfer events driving fast-mode wave fronts in the magnetosheath. These fronts push out the bow shock surface due to their increased downstream pressure. The resulting bow shock deformations lead to a configuration favourable to localized ion reflection and thus the formation of transient, travelling foreshock-like field-aligned ion beams. This is identified in two-dimensional global magnetospheric hybrid-Vlasov simulations of the Earth's magnetosphere performed using the Vlasiator model (http://vlasiator.fmi.fi). We also present observational data showing the occurrence of dayside reconnection and flux transfer events at the same time as Geotail observations of transient foreshock-like field-aligned ion beams. The spacecraft is located well upstream of the foreshock edge and the bow shock, during a steady southward interplanetary magnetic field and in the absence of any solar wind or interplanetary magnetic field perturbations. This indicates the formation of such localized ion foreshocks.

scholarly journals Dependence of the dayside magnetopause reconnection rate on local conditions

2015 ◽  
Vol 120 (8) ◽  
pp. 6386-6408 ◽  
Author(s):  
Shan Wang ◽  
Lynn M. Kistler ◽  
Christopher G. Mouikis ◽  
Steven M. Petrinec
Keyword(s):  
Reconnection Rate ◽  
Local Conditions ◽  
Dayside Magnetopause ◽  
Magnetopause Reconnection

Dependence of magnetopause reconnection events on interplanetary parameters

2020 ◽  
Author(s):  
Walter Gonzalez ◽  
Daiki Koga
Keyword(s):  
Solar Wind ◽  
Mach Number ◽  
Electric Field ◽  
Magnetic Reconnection ◽  
Flow Direction ◽  
Time History ◽  
Normal Vector ◽  
Dayside Magnetopause ◽  
Energy And Momentum ◽  
Magnetopause Reconnection

<p>Magnetic reconnection permits topological rearrangements of the interplanetary and magnetospheric magnetic fields and the entry of solar wind mass, energy, and momentum into the magnetosphere. Thus, magnetic reconnection is a key issue to understand space weather. However, it hasnot been fully understood yet under which interplanetary/magnetosheath conditions magnetic reconnection takes place more effectively at the dayside magnetopause. For this purpose,  in the present study 25 dayside magnetopause reconnection events are investigated using the Time History of Events and Macroscale Interactions during Substorms ( THEMIS ) spacecraft  observations. It was found, (1) that the reconnection electric field is proportional to the interplanetary electric field, (2) that the reconnection electric field is inversely proportional to the solar wind-Alfvén Mach number,  (3) that thereconnection outflow speed is proportional to the solar wind Alfvén speed, and (4) that the reconnection outflow speed is  inversely proportional to the magnetosheath plasma beta. Finally, it is shown that the range of magnetic shear angles for which magnetic reconnection should occur is restricted to large shears as the magnetosheath flow direction becomes more perpendicular to the direction of the local magnetopause normal vector. Since these results refer to fairly typical solar wind-Alfvén Mach number condition, they may not apply to more extreme cases.</p>

scholarly journals Ion acceleration dependence on magnetic shear angle in dayside magnetopause reconnection

2015 ◽  
Vol 120 (9) ◽  
pp. 7255-7269 ◽  
Author(s):  
S. K. Vines ◽  
S. A. Fuselier ◽  
K. J. Trattner ◽  
S. M. Petrinec ◽  
J. F. Drake
Keyword(s):  
Shear Angle ◽  
Ion Acceleration ◽  
Magnetic Shear ◽  
Dayside Magnetopause ◽  
Magnetopause Reconnection

Dayside magnetopause reconnection

1985 ◽  
Vol 90 (A2) ◽  
pp. 1781 ◽  
Author(s):  
Martin F. Heyn ◽  
Helfried K. Biernat ◽  
Vladimir S. Semenov ◽  
Igor V. Kubyshkin
Keyword(s):  
Dayside Magnetopause ◽  
Magnetopause Reconnection

scholarly journals The location and rate of dayside reconnection during an interval of southward interplanetary magnetic field

2003 ◽  
Vol 21 (7) ◽  
pp. 1467-1482 ◽  
Author(s):  
M. Pinnock ◽  
G. Chisham ◽  
I. J. Coleman ◽  
M. P. Freeman ◽  
M. Hairston ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Polar Cap ◽  
Reconnection Rate ◽  
Comprehensive Description ◽  
Total Potential ◽  
Radar Network ◽  
Dayside Magnetopause ◽  
Magnetic Field Model ◽  
Magnetopause Reconnection

Abstract. Using ionospheric data from the SuperDARN radar network and a DMSP satellite we obtain a comprehensive description of the spatial and temporal pattern of day-side reconnection. During a period of southward interplanetary magnetic field (IMF), the data are used to determine the location of the ionospheric projection of the dayside magnetopause reconnection X-line. From the flow of plasma across the projected X-line, we derive the reconnection rate across 7 h of longitude and estimate it for the total length of the X-line footprint, which was found to be 10 h of longitude. Using the Tsyganenko 96 magnetic field model, the ionospheric data are mapped to the magnetopause, in order to provide an estimate of the extent of the reconnection X-line. This is found to be ~ 38 RE in extent, spanning the whole dayside magnetopause from dawn to dusk flank. Our results are compared with previously reported encounters by the Equator-S and Geotail spacecraft with a reconnecting magnetopause, near the dawn flank, for the same period. The SuperDARN observations allow the satellite data to be set in the context of the whole magnetopause reconnection X-line. The total potential associated with dayside reconnection was ~ 150 kV. The reconnection signatures detected by the Equator-S satellite mapped to a region in the ionosphere showing continuous flow across the polar cap boundary, but the reconnection rate was variable and showed a clear spatial variation, with a distinct minimum at 14:00 magnetic local time which was present throughout the 30-min study period.Key words. Magnetospheric physics (magnetopause, cusp and boundary layers; magnetosphere-ionoshere interactions) – Space plasma physics (magnetic reconnection)

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