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Title: Magnetospheric convection effects at mid-latitudes 3. Theoretical derivation of the disturbance convection pattern in the plasmasphere

Journal Article · · J. Geophys. Res.; (United States)

A theoretical investigation of the generating mechanisms of the disturbance E x B drifts observed at mid-latitudes in performed, with the purpose of understanding the local time dependence of the average disturbance drifts observed above Saint-Santin (L = 1.8, 47/sup 0/ geomagnetic latitude) and of extending if to other latitudes. To this end, the middle- and low-latitude effects of the two possible generators of electric field disturbances, the solar wind/magnetosphere dynamo, and the ionospheric wind disturbance dynamo, computed by means of a numerical dynamo model of the ionosphere, are systematically compared with the Saint-Santin disturbance drift pattern.Three latitude zones can be distinguished in the resulting picture. In the external regions of the plasmasphere, one finds an extension of the usual picture of high-latitude plasma drifts, eastward in the morning and westward in the afternoon. The calculated drifts compare fairly well with the drifts disturbance models produced from whistler data at L = 4 and from the Millstone Hill radar. At mid-latitudes, between 55/sup 0/ and 20/sup 0/ invariant latitude, we predict that the superposition of the two dynamos produces westward drifts at all local times; this is consistent with the Saint-Santin and Arecibo radar drift data.

Research Organization:
CNET/Centre de Recherches en Physique de l'Environnement Terrestre et Planetaire, 92131 Issy-Les-Moulineaux, France
OSTI ID:
6034419
Journal Information:
J. Geophys. Res.; (United States), Vol. 88:A1
Country of Publication:
United States
Language:
English