ON THE ORIGIN OF THE TYPE II SPICULES: DYNAMIC THREE-DIMENSIONAL MHD SIMULATIONS

Journal Article · Wed Jul 20 00:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/736/1/9· OSTI ID:21578363

MartInez-Sykora, Juan ^[1]; Hansteen, Viggo ^[2]; Moreno-Insertis, Fernando ^[3]

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1. Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304 (United States)
2. Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway)
3. Instituto de Astrofisica de Canarias, 38200 La Laguna (Tenerife) (Spain)

Recent high temporal and spatial resolution observations of the chromosphere have forced the definition of a new type of spicule, 'type II's', that are characterized by rising rapidly, having short lives, and by fading away at the end of their lifetimes. Here, we report on features found in realistic three-dimensional simulations of the outer solar atmosphere that resemble the observed type II spicules. These features evolve naturally from the simulations as a consequence of the magnetohydrodynamical evolution of the model atmosphere. The simulations span from the upper layer of the convection zone to the lower corona and include the emergence of a horizontal magnetic flux. The state-of-art Oslo Staggered Code is used to solve the full MHD equations with non-gray and non-LTE radiative transfer and thermal conduction along the magnetic field lines. We describe in detail the physics involved in a process which we consider a possible candidate for the driver mechanism that produces type II spicules. The modeled spicule is composed of material rapidly ejected from the chromosphere that rises into the corona while being heated. Its source lies in a region with large field gradients and intense electric currents, which lead to a strong Lorentz force that squeezes the chromospheric material, resulting in a vertical pressure gradient that propels the spicule along the magnetic field, as well as Joule heating, which heats the jet material, forcing it to fade.

• OSTI ID: 21578363
• Journal Information: Astrophysical Journal, Vol. 736, Issue 1; Other Information: DOI: 10.1088/0004-637X/736/1/9; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CHROMOSPHERE
CONVECTION
LTE
MAGNETIC FLUX
MAGNETOHYDRODYNAMICS
RADIANT HEAT TRANSFER
SIMULATION
SOLAR CORONA
SOLAR PROMINENCES
THREE-DIMENSIONAL CALCULATIONS
ATMOSPHERES
ENERGY TRANSFER
EQUILIBRIUM
FLUID MECHANICS
HEAT TRANSFER
HYDRODYNAMICS
MASS TRANSFER
MECHANICS
SOLAR ACTIVITY
SOLAR ATMOSPHERE
STELLAR ACTIVITY
STELLAR ATMOSPHERES
STELLAR CORONAE