Premium
Coronal magnetic field analysis with Faraday rotation observations of Alfven waves
Author(s) -
Jensen E. A.,
Russell C. T.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl036257
Subject(s) - physics , alfvén wave , magnetic field , solar wind , computational physics , faraday effect , dipole model of the earth's magnetic field , monochromatic color , field (mathematics) , rotation (mathematics) , magnetohydrodynamics , astrophysics , interplanetary magnetic field , optics , quantum mechanics , geometry , mathematics , pure mathematics
Faraday rotation observations of an Alfven wave at 4 solar radii during the January 9, 1983 superior conjunction of the Helios spacecraft were simultaneously obtained in Goldstone, California and Canberra, Australia allowing the measurement of the Alfven wave speed. We find that the T. Hoeksema et al. (1982) potential field source surface model performs better than the M. Paetzold et al. (1987) magnetic field magnitude model for predicting the magnitude of the magnetic field in the region based on the observed Alfven speed. Assuming the Alfven wave is monochromatic, coherent, and radially propagating, we determine the minimum magnetic field fluctuation required to reproduce the observations. We use the minimum magnetic field fluctuation to calculate the minimum Alfven wave energy flux of 6 × 10 19 W; this is approximately 20% of the wave energy required to accelerate the solar wind.