Quasi-rigid rotation of coronal magnetic fields

Journal Article · Fri Apr 01 04:00:00 EST 1988 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/166205· OSTI ID:6995873

Wang, Y M; Sheeley, Jr, N R; Nash, A G; Shampine, L R

Spherical harmonic analysis and numerical simulations are used to study the rotational properties of the coronal magnetic field under the assumption that it can be approximated by a current-free extension of the photospheric field. It is found that the rotation rate in the outer corona is determined, principally, by coronal filtering, the global averages of the photospheric rotation rate, and ongoing source eruptions. The present model is able to account for observationally inferred rotational properties. It is suggested that the coronal rotation rate accelerates gradually due to the equatorward migration of sunspots, and that the 27-day equatorial period is approached toward sunspot minimum as the decaying photospheric flux becomes localized near the equator. 36 references.

• Research Organization: E. O. Hulburt Center for Space Research, Washington, DC (USA)
• OSTI ID: 6995873
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 327; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
MAGNETIC FIELDS
MATHEMATICAL MODELS
MATHEMATICS
MOTION
NUMERICAL ANALYSIS
PHOTOSPHERE
ROTATION
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR CORONA
SPHERICAL HARMONICS
STAR MODELS
STELLAR ATMOSPHERES
STELLAR CORONAE