Quasiperiodic oscillations observed at the edge of an auroral arc by Auroral Turbulence 2

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.