Polar coronal plumes

Polar coronal plumes are modeled using concentrations of magnetic flux at 1.01R, and assuming the field is current-free, or a potential field. Identifying the density enhancement of plumes with magnetic flux concentration produces good agreement between 1.01R and 1.10R, for model conditions of a large background magnetic field and a plume separation of 50 000 to 70 000 km at the base. Beyond 1.10R, both plumes and the potential field diverge very nearly as r².Also Department of Astrogeophysics, University of Colorado, Boulder, Colo. 80309, U.S.A. Presently visiting Stanford University Institute for Plasma Research, Via Crespi, Stanford, Calif. 94303, U.S.A.