The plots below show the different high time resolution plots from EPIC indicating the time of flight related dispersion of different energies ahead of the plasmoid. Indeed the character changes once the flow arrives into a convective distribution, whereas at onset the particles arive ballistically at the satellite. From the time of the fastest particles we infer that the onset of the acceleration was earlier than 11:26:30 UT, in accordance with the calculations of Petrukovich et al. We can get a much better handle on the timing by linear regression. Note that the absence of electrons does not invalidate the conclusions. We may be able to get timing off of low energy electrons too. I will do the accurate timing tomorrow and get back to you with a corrsponding plot.

Figure 0 shows the high resolution data from ICS and MGF and EFI.

jgrpaperfigure.gif is the .gif file of the JGR paper figure.

jgrpaperfigure.ps is the .ps file of the JGR paper figure.

Notice the large gradient anisotropy of the particles indicating that they appear from below the spacecraft. This, in turn shows that the phenomenon starts next to the neutral sheet, not the boundary layer, in this case.

Figure 1both shows the high resolution data from ICS. (Also note the new figure ics.gif which shows how the background masks onset determination from e_b2. Data are collected from both heads of the instrument (up and down) and averaged to produce this plot. Separate plots with only the upward looking head, (Figure 1up), and only the down looking head, (Figure 1down), indicate that the appearance of the duskward anisotropic particles is near simultaneous. This is surprising at first. The surprise comes from the fact that the field is pointing up and the up head is expected to have smaller pitch angles than the down head (field elevation is 30 degrees at the time). In fact, given the angle difference between up and down heads of more than 35 degrees, it is an unexpected result to see the particles of >35 deg. pitch angle arrive at the same time at the zero pitch angles. Such large pitch angle particles have speeds less than half the speed of the zero pitch angle particles and could not have arrived at the same time from the source. On second thought, this indicates that the flux tube below the satellite is filled with ballistically moving particles of zero pitch angle from the source; the initially field aligned particles pitch angle scatter locally and fill a large portion of the phase space.

Question: What causes such effective pitch angle scattering? I see no wave enhancement at the time (below 20 Hz). Could it be higher freq. waves? How could those resonate with ions? Probably not.

Answer: 1. Could it be non-adiabatic motion? Assuming initially particles of zero pitch angle escaping from the reconnection/activity region: the argument Rcurvature > rgyro does not apply because rgyro is very very small.

Answer: 2. Could it be first adiabatic invariant conservation along the flight path? Yes. Starting from a small field the field increases towards the satellite and the pitch angles expand continually. Some particles remain behind but locally, at least, the field aligned |B| gradient is such that allows PA expansion to the level seen.

lineplot shows the antisunward fluxes and their rise at the time of the event.

lineplot2 shows in a more expanded format (for timing) the same rise.

TOF shows the timing analysis of the arrival of near-zero degree pitch angles of channels He2,M2, E3, E4, T14. The linear correlation of the arrival times strongly suggests a time of flight dispersion of the different energy particles (not spatial because of the discussion above) and points to the time of onset to be 11:24:22 UT. If a spatial dispersion of the fluxes is argued, the onset time would have to be placed somewhat earlier.