scholarly journals Concerning the motion of flux transfer events generated by component reconnection across the dayside magnetopause

2010 ◽  
Vol 115 (A4) ◽  
pp. n/a-n/a ◽  
Author(s):  
D. G. Sibeck ◽  
R.-Q. Lin
Keyword(s):  
Flux Transfer Events ◽  
Dayside Magnetopause ◽  
Flux Transfer

The Effect of Solar Wind Mach Numbers on the Occurrence Rate of Flux Transfer Events at the Dayside Magnetopause

2019 ◽  
Vol 46 (8) ◽  
pp. 4106-4113 ◽  
Author(s):  
C. Chen ◽  
T. R. Sun ◽  
C. Wang ◽  
Z. H. Huang ◽  
B. B. Tang ◽  
...  
Keyword(s):  
Solar Wind ◽  
Occurrence Rate ◽  
Flux Transfer Events ◽  
Dayside Magnetopause ◽  
Mach Numbers ◽  
Flux Transfer

scholarly journals Concerning the occurrence pattern of flux transfer events on the dayside magnetopause

2009 ◽  
Vol 27 (2) ◽  
pp. 895-903 ◽  
Author(s):  
D. G. Sibeck
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Reconnection ◽  
Interplanetary Magnetic Field ◽  
Flux Transfer Events ◽  
Dayside Magnetopause ◽  
Two Factors ◽  
Flux Transfer ◽  
Occurrence Pattern ◽  
The Magnetic Field

Abstract. We present an analytical model for the magnetic field perturbations associated with flux transfer events (FTEs) on the dayside magnetopause as a function of the shear between the magnetosheath and magnetospheric magnetic fields and the ratio of their strengths. We assume that the events are produced by component reconnection along subsolar reconnection lines with tilts that depend upon the orientation of the interplanetary magnetic field (IMF), and show that the amplitudes of the perturbations generated during southward IMF greatly exceed those during northward IMF. As a result, even if the distributions of magnetic reconnection burst durations/event dimensions are identical during periods of northward and southward IMF orientation, events occurring for southward IMF orientations must predominate in surveys of dayside events. Two factors may restore the balance between events occurring for northward and southward IMF orientations on the flanks of the magnetosphere. Events generated on the dayside magnetopause during periods of southward IMF move poleward, while those generated during periods of northward IMF slip dawnward or duskward towards the flanks. Due to differing event and magnetospheric magnetic field orientations, events that produce weak signatures on the dayside magnetopause during intervals of northward IMF orientation may produce strong signatures on the flanks.

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 Flux Transfer Events: 1. generation mechanism for strong southward IMF

2006 ◽  
Vol 24 (1) ◽  
pp. 381-392 ◽  
Author(s):  
J. Raeder
Keyword(s):  
Magnetic Field ◽  
Generation Process ◽  
Numerical Resolution ◽  
Flux Transfer Events ◽  
Dayside Magnetopause ◽  
Semiannual Variation ◽  
Flux Transfer ◽  
Sequential Generation ◽  
The Magnetic Field ◽  
Dipole Tilt

Abstract. We use a global numerical model of the interaction of the solar wind and the interplanetary magnetic field with Earth's magnetosphere to study the formation process of Flux Transfer Events (FTEs) during strong southward IMF. We find that: (i) The model produces essentially all observational features expected for FTEs, in particular the bipolar signature of the magnetic field BN component, the correct polarity, duration, and intermittency of that bipolar signature, strong core fields and enhanced core pressure, and flow enhancements; (ii) FTEs only develop for large dipole tilt whereas in the case of no dipole tilt steady magnetic reconnection occurs at the dayside magnetopause; (iii) the basic process by which FTEs are produced is the sequential generation of new X-lines which makes dayside reconnection inherently time dependent and leads to a modified form of dual or multiple X-line reconnection; (iv) the FTE generation process in this model is not dependent on specific assumptions about microscopic processes; (v) the average period of FTEs can be explained by simple geometric arguments involving magnetosheath convection; (vi) FTEs do not develop in the model if the numerical resolution is too coarse leading to too much numerical diffusion; and (vii) FTEs for nearly southward IMF and large dipole tilt, i.e., near solstice, should only develop in the winter hemisphere, which provides a testable prediction of seasonal modulation. The semiannual modulation of intermittent FTE reconnection versus steady reconnection is also expected to modulate magnetospheric and ionospheric convection and may thus contribute to the semiannual variation of geomagnetic activity.

scholarly journals Ionospheric ion upwelling in the wake of flux transfer events at the dayside magnetopause

1988 ◽  
Vol 93 (A6) ◽  
pp. 5641 ◽  
Author(s):  
M. Lockwood ◽  
M. F. Smith ◽  
C. J. Farrugia ◽  
G. L. Siscoe
Keyword(s):  
Flux Transfer Events ◽  
Dayside Magnetopause ◽  
Flux Transfer ◽  
Ion Upwelling

scholarly journals The azimuthal extent of three flux transfer events

2008 ◽  
Vol 26 (8) ◽  
pp. 2353-2369 ◽  
Author(s):  
R. C. Fear ◽  
S. E. Milan ◽  
A. N. Fazakerley ◽  
E. A. Lucek ◽  
S. W. H. Cowley ◽  
...  
Keyword(s):  
Flux Tube ◽  
Time Varying ◽  
Magnetic Shear ◽  
Simple Interpretation ◽  
Flux Transfer Events ◽  
Dayside Magnetopause ◽  
In Situ Observations ◽  
Flux Transfer ◽  
Separation Size

Abstract. In early 2006, the Cluster spacecraft crossed the dayside magnetopause twice each orbit with the spacecraft at their largest separation of the entire mission (~10 000 km). In this paper, we present in situ observations at this separation size of flux transfer events (FTEs), which are a signature of transient or time-varying magnetopause reconnection. We study a magnetopause crossing on 27 January 2006; for half an hour, the tetrahedron of Cluster spacecraft straddled the magnetopause and during this time a large number of flux transfer events were observed. Three particular FTEs were observed by all four spacecraft, enabling it to be shown that individual FTEs at the magnetopause can extend azimuthally for at least 10 000 km. By combining the Cluster tetrahedron geometry with the observed velocity of the FTEs, it can be shown that the poleward extent of one FTE is significantly smaller than its azimuthal extent. The location of the Cluster spacecraft when they observed this FTE suggests that it is inconsistent with the simple interpretation of an "elbow-shaped" flux tube. The FTE's azimuthal extent suggests that it was more likely generated at a comparatively long reconnection line or lines, although the magnetic shear across the magnetopause is not high enough to exclude the "elbow-shaped" model entirely.

A Study of Orientation and Motion of Flux Transfer Events Observed at High-Latitude Dayside Magnetopause

2005 ◽  
Vol 48 (6) ◽  
pp. 1307-1315 ◽  
Author(s):  
Li YAO ◽  
Shao-Liang LIU ◽  
Shu-Ping JIN ◽  
Zhen-Xing LIU ◽  
Jian-Kui SHI ◽  
...  
Keyword(s):  
High Latitude ◽  
Flux Transfer Events ◽  
Dayside Magnetopause ◽  
Flux Transfer

scholarly journals Cluster PEACE observations of electrons during magnetospheric flux transfer events

2001 ◽  
Vol 19 (10/12) ◽  
pp. 1509-1522 ◽  
Author(s):  
C. J. Owen ◽  
A. N. Fazakerley ◽  
P. J. Carter ◽  
A. J. Coates ◽  
I. C. Krauklis ◽  
...  
Keyword(s):  
Boundary Layers ◽  
Plasma Electron ◽  
Local Times ◽  
Current Layer ◽  
Flux Tubes ◽  
Flux Transfer Events ◽  
Dayside Magnetopause ◽  
Flux Gate ◽  
Flux Transfer ◽  
Open Flux

Abstract. During the first quarter of 2001 the apogees of the Cluster spacecraft quartet precessed through midday local times. This provides the first opportunity for 4 spacecraft studies of the bow shock, magnetosheath and the dayside magnetopause current layer and boundary layers. In this paper, we present observations of electrons in the energy range ~ 10 eV–26 keV made by the Plasma Electron And Current Experiment (PEACE) located just inside the magnetopause boundary, together with supporting observations by the Flux Gate Magnetometer (FGM). During these observations, the spacecraft have separations of ~ 600 km. This scale size is of the order or less than the typical size of flux transfer events (FTEs), which are expected to be observed following bursts of reconnection on the dayside magnetopause. We study, in detail, the 3-D configuration of electron populations observed around a series of enhancements of magnetosheath-like electrons which were observed within the magnetosphere on 2 February 2001. We find that individual spacecraft observe magnetic field and electron signatures that are consistent with previous observations of magnetospheric FTEs. However, the differences in the signatures between spacecraft indicate that these FTEs have substructure on the scale of the spacecraft separation. We use these differences and the timings of the 4 spacecraft observations to infer the motions of the electron populations and thus the configuration of these substructures. We find that these FTEs are moving from noon towards dusk. The inferred size and speed of motion across the magnetopause, in one example, is ~ 0.8 RE and ~ 70 km s-1 respectively. In addition, we observe a delay in and an extended duration of the signature at the spacecraft furthest from the magnetopause. We discuss the implications of these 4 spacecraft observations for the structure of these FTEs. We suggest that these may include a compression of the closed flux tubes ahead of the FTE, which causes density and field strength enhancements; a circulation of open flux tubes within the FTE itself, which accounts for the delay in the arrival of the magnetosheath electron populations at locations deepest within the magnetosphere; and a possible trapping of magnetospheric electrons on the most recently opened flux tubes within the FTE.Key words. Magnetospheric physics (magnetopause, cusp and boundary layers; solar wind - magnetosphere interactions)

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