Meridional Flow in the Solar Wind

Abstract

8 a We look for evidence of meridional flow in the solar wind using data from IMP nd Voyager 2. Magnetic field data are used to separate the plasma data according to - d whether the spacecraft is above or below the heliospheric current sheet. IMP 8 meri ional velocities are predominately poleward, with an average poleward flow of 1 km/s f e in each hemisphere. Voyager 2 velocities are also generally poleward, but regions o quatorward flow are also observed; the largest poleward speeds (4 km/s) occur near t f solar minimum. The magnitude of the poleward flow is not large enough to accoun or the magnetic flux deficits observed by Pioneer 10. T Introduction he concept that meridional plasma flows are implied by Parker's [1958] spiral field e t approximation was first developed by Winge and Coleman [1972]. They generaliz he Weber-Davis model of the solar wind [Weber and Davis, 1967] to include latitudil p nal effects and find that the resulting equations predict that the sola..