Effects of stream-associated fluctuations upon the radial variation of average solar wind parameters
Abstract
The effects of nonlinear fluctuations due to solar wind streams upon radial gradients of average solar wind parameters are computed by using a numerical MHD model for both spherically symmetric time-dependent and corotating equatorial flow approximations. We find significant effects of correlations between fluctuations upon the gradients of azimuthal magnetic field, radial velocity, density, and azimuthal velocity. The averages of Vr and r²n both decrease with increasing radial distance (0-30 km/s, 5-10% by 6 AU) while mass flux is conserved. The cross-variance between Vr and r²n increases with radial distance from negative values to positive values at distances greater than 3.5 AU. The average azimuthal velocity decreases, and at distances greater than 4 AU it may be opposite to the solar rotation; <Vϕ> of from 0.2 to -1.7 km/s at 6 AU is predicted. Between 400 and 900 RS, stream interactions have transferred the major portion of the angular momentum flux to the magnetic field; at even greater distances the plasma again carries the bulk of the angular momentum flux. The average azimuthal component of the magnetic field may decrease as much as 10% faster than the Archimedean spiral out to 6 AU, owing to stream interactions, but this result is dependent upon inner boundary conditions.
- Publication:
-
Journal of Geophysical Research
- Pub Date:
- March 1977
- DOI:
- 10.1029/JA082i007p01095
- Bibcode:
- 1977JGR....82.1095G
- Keywords:
-
- Magnetohydrodynamics;
- Plasma Density;
- Radial Distribution;
- Solar Wind;
- Solar Wind Velocity;
- Angular Momentum;
- Interplanetary Magnetic Fields;
- Ion Temperature;
- Magnetohydrodynamic Waves;
- Momentum Transfer;
- Plasma Dynamics;
- Radial Velocity;
- Particles and Fields-Interplanetary Space: Solar wind magnetic fields;
- Particles and Fields-Interplanetary Space: Solar wind plasma