Empirical Relationship between the Magnetic Field and the Mass and Energy Flux in the Source Regions of the Solar Wind
Abstract
Using daily averages of the solar wind speed and mass density measured at Earth together with an improved method for extrapolating the observed photospheric field to 1 AU, we construct scatter plots relating the coronal field strength B0 to the mass flux density rho 0v0 and the total energy flux density Fw0 at the coronal base. On average, both rho 0v0 and Fw0 increase roughly linearly with B0; they also show a monotonic increase with the coronal flux-tube expansion factor. However, the wind speed at Earth, determined by the ratio Fw0/( rho 0v0), is essentially independent of B0, while tending to decrease with increasing expansion factor (as found in earlier studies).
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1995
- DOI:
- 10.1086/309650
- Bibcode:
- 1995ApJ...449L.157W
- Keywords:
-
- SUN: SOLAR WIND;
- SUN: CORONA;
- SUN: MAGNETIC FIELDS