Electromagnetic structure in auroral latitudes according to data of the Interkosmos - Bulgaria - 1300 satellite

Intensive electromagnetic disturbances in auroral region at altitudes ∼ 900 km detected with the ''Interkosmos-Bulgaria - 1300'' satellite are analyzed. An attempt is undertaken to find out common regularities in their structures. A certain class of events in which electric and magnetic field disturbances have an identical form is singled out. These events represent the result of oblique Alfven waves propagation with λz ∼ 3x103, λx ≤ 10 km and f ∼ 1 Hz. The absence of visible correlation between mutually perpendicular components of electric and magnetic fields is caused by a considerable phase shift between electric and magnetic field disturbances which indicates the interference of incident and reflected from ionosphere waves