Numerical simulations of the rebound shock model for solar spicules

Journal Article · Thu Feb 01 04:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168352· OSTI ID:7135285

Sterling, A C; Mariska, J T ^[1]

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1. E. O. Hulburt Center for Space Research, Washington, DC (USA)

Using time-dependent numerical simulations, the proposed rebound shock mechanism for spicules has been examined. At temperatures above a critical value, T(c), the radiation is characteristic of the conditions in the optically thin corona and near optically thin transition region. When T less than T(c), the atmosphere has a radiative cooling time, tau(rad) characteristic of chromosphere. The spicule is initiated with a quasi-impulsive force in the low chromosphere, which drives a train of upward propagating rebound shocks along the rigid magnetic flux tube. These shocks then move the transition region upward. The material below the displaced transition region has temperatures and densities similar to those of spicules when T(c) = 20,000 K or more and tau(rad) = 500 s or more, but not when T(c) = 10,000 K, and probably not when tau(rad) = 100 s. For all the cases where the cross sectional area diverges rapidly with height, the upward velocity of the transition region is less than that of spicules. Moreover, the maximum height is less than that of average spicules. Taller, higher velocity spicules result when the magnetic field cross sectional area is constant. In all cases, the rebound shock mechanism produces substantial motions and temperature and density variations in chromospheric and transition region material. It is suggested that this may be a partial explanation for the continuous dynamic state of the lower solar atmosphere. 30 refs.

• OSTI ID: 7135285
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 349; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CHROMOSPHERE
MAGNETIC FLUX
MATHEMATICAL MODELS
MORPHOLOGY
SHOCK WAVES
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR CORONA
SOLAR GRANULATION
STELLAR ATMOSPHERES
STELLAR CORONAE
TEMPERATURE DISTRIBUTION
WAVE PROPAGATION