A possible large-scale meridional structure in the helioequatorial solar wind

OVER the past few years observational data for a large-scale meridional structure of the solar wind have been accumulated 1–3 . Space-probe measurements have revealed heliolatitudinal effects at 1 AU, but little is known about the wind flow pattern at small radial distances, just outside the corona. Here we report the existence of a solar equatorial belt, from which few protons are emitted, and we discuss its causes.