Low Energy Ion Outflow Comparison with Terrestrial Low Energy Neutral Emissions

Part 1: Comparisons from higher altitude perspective
Part 2: Comparisons from lower altitude perspective

Part 1: Comparisons from higher altitude perspective

Observations:

LENA - Low energy neutral atom signatures from northern, high latitudes
TIDE - Low energy field-aligned outflowing ions originating from northern, high latitudes

Goal:
Show that variations in the observed outflowing flux qualitatively track variations in the neutral atom count rate.

Analysis:
A. Identify case study periods for which,
1) LENA observes northern, high latitude neutral emissions
2) POLAR is oriented along field lines threading to northern, high latitudes and TIDE observes appreciable field aligned ion fluxes with minimal interference from the spacecraft potential.

B. 10 cases were identified for which appropriate, simultaneous LENA and TIDE data were available. Six cases had a prayer for some comparison. Three intervals were identified during which both instruments appear to be observing related populations.

LENA intervalSelected LENA imagesTIDE interval
2000Jun23 1120-1300 2000Jun23 1156-1202 2000Jun23 0930-1130
2000Jun26 1045-1300 2000Jun26 1113-1119 2000Jun26 0930-1200
2000Jul16 0005-0200 2000Jul16 0157_0159
2000Jul15 2358_0000
2000Jul15 2300-0210

C. The figure compares the average LENA count rate over the period of interest with the corresponding average flux of outflowing ions observed by TIDE.

Conclusion:
Higher neutral source emissions correlate well with higher ion outflows.