Two-dimensional pressure structure of a coronal loop

Abstract

The steady-state pressure structure of a solar coronal loop is discussed using the theory of magnetohydrodynamical turbulence in cylindrical geometry. The steady state is represented by the superposition of two Chandrasekhar-Kendall functions. This representation, in principle, can delineate the three-dimensional temperature structure of the coronal loop. This paper is restricted to a two-dimensional modeling, since only this structure submits itself to the scrutiny of the available observations. The radial as well as the axial variations of the pressure in a constant density loop are calculated. These variations are found to conform to the observed features of cool core and hot sheath of the loops, as well as to the location of the temperature maximum at the apex of the loop. It is found that these features are not present uniformly all along either the length of the loop or across the radius, as will be shown in the text. Also discussed is the possible oscillatory nature of these pressure variations, and the associated time periods have been estimated.