Alfvén Waves in a Two-Fluid Model of the Solar Wind
Abstract
We present a two-fluid model for the solar wind which includes the presence of Alfvén waves which originate at the Sun. The effective pressure of the Alfvén waves is included, as well as a model representation for proton heating via nonlinear damping of the Alfvén waves. The effects of rotation in the solar equatorial plane are self-consistently included. Our principal results are summarized as follows: 1) Our calculations reproduce the correlation at 1 a.u. quite well for V <% 450km 1 This supports the idea that Alfvén waves of solar origin are responsible for the high-speed streams. 2) An Alfvénic energy flux of 6000 ergs -1 at the Sun yields values for Tp, V, and nat 1 a.u. which agree well with the data. 3) Wave pressure tends to produce a positive n-v correlation at 1 a.u., contrary to the observed negative correlation. This suggests that the cross-section of the high-speed streams may increase more rapidly than r2. 4) Including the spiral magnetic field in the electron energy equation worsens the disagreement between observed and calculated values of T at 1 a.u., if the electron heat conductivity is given by the collisional value. More work on the electron energy equation is needed. 5) Peripheral to our main theme, we present (a) general derivation of the conservation equations in the presence of Alfvén waves; (b) a simple, new derivation for the properties of Alfvén waves in a spiral field; and (c) a new power series for the electron temperature near r = , in the presence of a spiral magnetic field. Subject headings: hydromagnetics - solar wind
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1973
- DOI:
- 10.1086/152072
- Bibcode:
- 1973ApJ...181..547H