Solar Wind Outflow in Polar Plumes from 1.05 to 2.4 R ⊙

Abstract

An earlier publication (Paper I), which measured the outflow velocity in solar plumes out to 1.35 R☉ using the Doppler dimming technique, has here been extended out to 2.4 R☉ by including observations from SOHO UVCS. It is shown that plume outflow velocities, greater than interplumes at lower heights, have lower acceleration and fall below interplume velocities at heights greater than 1.6 R☉. This analysis resolves what has been an apparent disagreement between previously published work. The mass flow rate in plumes is shown to decrease with height, presumably through mass transfer to the interplume regions.