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 b order of an auroral are a quasiperiodic structure was observed by the magne tic and electric field instruments as well as by the particle detectors. Th e variations were temporal oscillations, but existed only in a narrow (appr oximate to 7 km) region transverse to the are, with a correlation length al ong the are of at least several km. The relation between the electric and m agnetic field amplitude indicates the Alfvenic nature of the variations. Fi eld aligned electron precipitation is correlated to the field variations. T he narrow band nature of the oscillations and frequency around 0.6 Hz is co nsistent with waves confined in the ionospheric Alfven resonator.