Cartoon illustrating the rotations undergone by a flux tube approaching a reconnection site. A magnetic field line bends in the (x, y) plane toward the x-point and bends in the (x, z) plane moving along the electron out of plane motion caused by the reconnection electric field. The dashed lines are projections onto the (x, z) of the field lines, showing this second bending.
Evolution of the reconnected flux, (adimensional quantity). Two phases are present, slow at first, followed by a fast phase starting at approximately time .
False color representation of and (adimensional quantities) at time . A line is shown at along which 256 probes are located. Several field lines are shown in white.
Space time (x–t) representation of the temporal evolution at all available virtual probes located at . Two components of the magnetic field are shown: and . To guide the comparison with linear theory (Sec. IV ), three reference lines are shown. The green line corresponds to the lower branch of the two fluid dispersion relation and the magenta lines to the upper branch. The specific slopes are from faster (more horizontal) to slower: (interpreted in the text as the local upper branch characteristics for the relevant transverse scale), (interpreted as a reference local Alfven speed), and (interpreted as the local lower branch characteristic for the relevant transverse scale). The color map of has been saturated to allow better viewing of the initial phase. The actual range is .
Eigenvalues of the Jacobian of the two-fluid equations, corresponding to the characteristics as a function of . The results are relative to the local conditions observed at the location of the virtual probes of the simulation results: and . Note that following tradition, the axis is normalized with the reference and not the local scaling factors (reference di and ω ci ). Three asymptotic lines are shown. Top (green): ; middle (red) Alfvén VA ; and bottom (blue), sound speed cs .
Domain of influence of the shear branch for the four-field model of a two fluid plasmas. Note that the domain of influence of the compressional branch is not reported to avoid cluttering. It would be located near the central horizontal axis. Three special characteristics are shown. Magenta: characteristic of maximum speed λ M (corresponding to ), black: characteristic corresponding to the reference , and white: slowest characteristic, corresponding to the Alfvén speed (in the limit of ).
Section (x–t) of the space-time false color representation of Sx and Sz . SI units is used (W/m2). The temporal evolution at all available virtual probes located at y = 8.8477 within a 2D (x, y) run is shown as a function of time.
Section (x–y) at time ω cit = 8.7312, false color representation of Sz . SI units are used (W/m2).
Speed of information traveling along the upper and lower characteristics of the two fluid models in Fig. 5 for three different perpendicular scales discussed in the text and their corresponding : scaleless, ion scale, and electron scale. The last two rows report the same value but measured in terms of the reference Alfvén speed rather than the local Alfvén speed. Values obtained for the local conditions at the position of the measuring virtual probes.
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