色球垂直加热和水平加热

HORIZONTAL AND VERTICAL HEATING IN SOLAR CHROMOSPHERE

本文用湍动波应力张量的各向异性,探讨了阿尔文湍动在一磁力管内引起的效应。在磁场为无力场并略去流动和热传导条件下导出管内一维定常流应遵从的方程。本文的计算结果可合理地解释谱斑观测事实:谱斑的密度和其周围的同量级但略高,温升约几百度,而水平加热模型可解释"谱斑桥"的超额温度。对于宁静区现象——亮结构常是垂直场强处,暗丝则对应于水平场占优势的地方——可认为是磁场强度不同引起对波的吸收差异造成的。

Using the anisotropy of the stress tensor of turbulent waves, the effects of Alfvén turbulence on a single magnetic tube are investigated. Under the assumptions of magnetic field being force-free and of neglecting thermal conduction and convection the equations governing the onedimensional steady flow in the tube are derived. And then, in terms of these equations the horizontal ad vertical heating in chromosphere are computed. It is fount that in both cases there seems to he an enhancement in the pressure as well as density, in other words, so-called "height fall effect" occurs. Furthermore it is shown that the heating efficiency in the horizontal case is higher than in the vertical ease and that the wave energy density of about 1% as strong as the thermal energy density can result in the temperature rise of hundreds degrees. Using the computed results in this paper it is possible to explain reasonably the observations of plages that the density in plages has the same order of magnitude as in their surroundings but the former is slightly higher than the latter and that the temperature enhancement in plages is about hundreds degrees. And using the model of horizontal heating,the excessive temperature in "the plage bridge" can be understood as well. The fact that in solar juiet regions the bright patches usually have a stronger vertical field and dark configurations often correspond to the regions having dominant horizontal field——might be illustrated by the different absorption of turbulent waves due to the differences of magnetic field strengths.