A numerical hydrodynamic model of a heated coronal loop

• Published in: Solar physics Vol. 103; no. 1; pp. 47 - 66
• Main Author: MacNeice, Peter
• Format: Journal Article
• Language: English
• Published: Boston, MA Reidel 01.01.1986; Dordrecht
• Subjects: Astronomy; Corona. Coronal loops, streamers, and holes; Earth, ocean, space; Exact sciences and technology; Solar physics; Solar system; Hydrodynamic model; Solar corona; Plasma; Coronal loop; Hydrogen
• ISSN: 0038-0938; 1573-093X
• DOI: 10.1007/BF00154858

The fluid equations describing a fully ionized single-temperature (i.e., electron and proton temperatures assumed identical) hydrogen plasma in a coronal loop subject to a transient heating pulse (2 x 10 super(9) ergs cm super(-) super(2) sec super(-) super(1) ) centered about the loop apex have been solved numerically. An adaptive regridding scheme was used to ensure adequate spatial resolution throughout the transition region, and appropriate consideration was given to the numerical time constants. Because of the fine gridding made possible by this scheme, these results represent the first reliable simulation of the impact of a downward-propagating conduction front on the transition region, and the early stages of the development of the downward-moving compression and upward ablation. Intensities in the OV (1371-A) transition region line were calculated from the model results. Estimates have been made of the importance of the downward-streaming collisionless high-energy tail of the distribution in the transition region resulting from the very steep temperature gradients. It is shown that the mass and energy densities are not substantially altered by the non-Maxwellian tail, except insofar as they are coupled to higher moments of the distribution function, such as the heat flux through the fluid equations.