Interplanetary Alfvenic fluctuations: A stochastic model

Journal Article · Tue Sep 01 04:00:00 EDT 1981 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA086iA09p07498· OSTI ID:5881757

Barnes, A

The strong alignment of the average directions of minimum magnetic variance and mean magnetic field in interplanetary Alfvenic fluctuations is inconsistent with the usual wave-propagation models. We investigate the concept of minimum variance for nonplanar Alfvenic fluctuations in which the field direction varies stochastically. It is found that the tendency of the minimum variance and mean field directions to be aligned may be purely a consequence of the randomness of the field direction. In particular, a well-defined direction of minimum variance does not imply that the fluctuations are necessarily planar. The fluctuation power spectrum is a power law for frequencies much higher than the inverse of the correlation time. The probability distribution of directions a randomly fluctuating field of constant magnitude is calculated. A new approach for observational studies of interplanetary fluctuations is suggested.

• Research Organization: Theoretical and Planetary Studies Branch, NASA Ames Research Center, Moffett Field, California 94035
• OSTI ID: 5881757
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 86:A9; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALFVEN WAVES
FLUCTUATIONS
HYDROMAGNETIC WAVES
INTERPLANETARY MAGNETIC FIELDS
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
ORIENTATION
STOCHASTIC PROCESSES
VARIATIONS
WAVE PROPAGATION