Solar Corona Magnetic Structure and Stagnated Wind Outflow

VÁSQUEZ, ALBERTO M.

Congreso; MAGNETIC FIELDS IN THE UNIVERSE: From Laboratory and Stars to Primordial Structures; 2004

Solar observations made with the Ultraviolet Coronagraph Spectrometer (UVCS) aboard the Solar and Heliosphere Observatory (SoHO) spacecraft, have revealed that coronal protons and heavier ions have anisotropic temperature distributions. In a recent work we developed semi-empirical models for the solar minimum corona to investigate the effect of the observed proton anisotropy on the coronal magnetic structure and the bimodal solar wind. Here we highlight the effect that the resulting particular geometry of the magnetic field around the streamer belt has on the solar wind. The open magnetic field lines surrounding the streamer belt (streamer legs) have non-monotonic expansion factors. This feature produces a stagnated outflow around the streamer magnetic cusp point, located at the top of the streamer belt closed magnetic field lines (streamer core). We find that this flow stagnation effect extends over quite important distances (of order 1Rsun) from the streamer cusp location.