A model of the sunspot umbra

Chitre, S. M. ; Shaviv, G. (1967) A model of the sunspot umbra Solar Physics, 2 (2). pp. 150-157. ISSN 0038-0938

PDF - Publisher Version

Official URL: http://www.springerlink.com/content/n51187813rx26t...

Related URL: http://dx.doi.org/10.1007/BF00155915


Equations governing the structure of the umbra of a single spot have been integrated on the spot-axis. It is shown that a consistent umbral model can be obtained only for a narrow range of the electron pressures at the spot surface. The spot center is found to be at a depth of about 400 km below the normal solar surface. The reduced energy flux observed at the surface is assumed to be due to the effect of the spot-magnetic field on subphotospheric convection and an empirical factor β is introduced to take into account the reduction in the convective energy flux. With an inferred expression for β as a function of the internal and magnetic-energy density it is shown that in a consistent model the physical variables in the spot approach their ambient values at about 2330 km below the undisturbed solar surface and at the same depth the energy flux approaches the normal solar value and the magnetic interference with convection vanishes. The present investigation is a refinement of an earlier paper by Chitre (1963).

Item Type:Article
Source:Copyright of this article belongs to Springer-Verlag.
ID Code:5816
Deposited On:19 Oct 2010 10:51
Last Modified:16 May 2016 16:15

Repository Staff Only: item control page