Abstract

Multiple inverted-V structures are commonly observed on the same auroral zone crossing by a low altitude orbiting satellite. They appear grouped and apparently result from an ionospheric and/or magnetospheric mechanism of stratification. AUREOL-3 satellite observations were analyzed to study their properties in the framework of the ionosphere-magnetosphere coupling model proposed by Tverskoy (1982). This model predicts some natural periodicity in the electrostatic potential profile in the order of 100-200 km at ionospheric altitudes that could account for oscillations experimentally observed in the auroral zone, such as successive inverted-Vs. These oscillations may naturally result when the initial pressure gradients needed to generate a large-scale field-aligned current have a sufficiently wide equatorial scale, of about I RE or more. (C) 2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.