A quantitative study of Ca II network geometry
Abstract
Ca II spectroheliograms covering the period from 1912 to 1974 have been studied by using techniques of quantitative stereology. It is found that the fractional area α occupied by the emission network boundaries varies from 0.43 to 0.54, with the areal fraction being larger for years of sunspot minimum. The number of cells per unit area N _{A}, decreases with increasing activity. The inner radius of the boundary wall has also been derived, as a function of epoch. While the width of the emission wall is nearly constant with activity, the average interior network cell size decreases with decreasing activity.
 Publication:

Solar Physics
 Pub Date:
 November 1983
 DOI:
 10.1007/BF00211950
 Bibcode:
 1983SoPh...89...35R
 Keywords:

 Calcium;
 Chromosphere;
 Solar Activity Effects;
 Solar Granulation;
 Spectroheliographs;
 Sunspots;
 Brightness Distribution;
 Correlation Coefficients;
 Solar Cycles;
 Solar Physics;
 Statistical Correlation;
 Solar Physics