Latitudinal Properties of the Solar Wind Outflow Speed Derived from UVCS Observations
Abstract
In this paper we investigate the latitudinal dependence of the outflow speed of the solar wind from SOHO/UVCS observations. To this end, we measure the intensity of the O VI doublet lines at 1031.9 Å and 1037.6 Å, and consider the ratio R = I1032/I1037 as a diagnostic for wind speed. At distances larger than 1.6 R?, a local minimum in the ratio R at mid latitudes is observed, that might be attributed to a local increase of the wind speed. To check whether this interpretation is plausible, we derived the velocity field of the solar wind from mass flux conservation, after mapping electron densities from synoptic observations and adopting a simple magnetic field configuration. It turns out that the outflow plasma speed shows a local peak at mid latitudes between 1.5 and 2.5 R?, as inferred from UVCS observations.
- Publication:
-
Romanian Astronomical Journal
- Pub Date:
- 1999
- Bibcode:
- 1999RoAJ....9S.111Z
- Keywords:
-
- SUN;
- CORONA;
- UV RADIATION;
- LINE PROFILES;
- SOLAR WIND