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- Ivchenko, Nickolay, et al.
(författare)
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Quasiperiodic oscillations observed at the edge of an auroral arc by Auroral Turbulence 2
- 1999
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 26:22, s. 3365-3368
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Tidskriftsartikel (refereegranskat)abstract
- The Auroral Turbulence II (AT2) sounding rocket carried three payloads into the auroral ionosphere where they crossed several are structures. At the border of an auroral are a quasiperiodic structure was observed by the magnetic and electric field instruments as well as by the particle detectors. The variations were temporal oscillations, but existed only in a narrow (approximate to 7 km) region transverse to the are, with a correlation length along the are of at least several km. The relation between the electric and magnetic field amplitude indicates the Alfvenic nature of the variations. Field aligned electron precipitation is correlated to the field variations. The narrow band nature of the oscillations and frequency around 0.6 Hz is consistent with waves confined in the ionospheric Alfven resonator.
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| 2. |
- Lynch, A., et al.
(författare)
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Multiple-point electron measurements in a nightside auroral arc : Auroral Turbulence II particle observations
- 1999
-
Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 26:22, s. 3361-3364
-
Tidskriftsartikel (refereegranskat)abstract
- We report here three-point measurements of bursty, velocity-dispersed, field-aligned electron precipitation at the poleward edge of a northward-moving, post-breakup, nightside auroral arc. The three-point measurement allows detection of the proper motion of the inverted-V arc, which is shown to be 550 m/sec northward. The velocity dispersion patterns are fitted to find the source altitude of the precipitation bursts as a function of distance from the poleward edge of the are. These source points are interpreted to trace out the low-altitude boundary of the inverted-V potential drop, which is seen to rise both in time, and in the northward direction. The precipitation bursts under the inverted-V are seen to have an are-aligned velocity which varies with time, and which is consistent with the measured E x B local drift speed.
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| 3. |
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