Dark Areas in He I 10 830 Å and Their Relation With Other Effects of Solar Activity

摘要

Absorption areas have been studied in the line He i 10 830 Å, where active regions are seen as dark areas. The initial data were the synoptic maps for 1975–2002, as well as daily images 1992–2002 from the National Solar Observatory, represented as fits files. Areas were identified of objects having common boundaries, inside which the intensity of each pixel was less than a threshold value. Properties of the measured areas were studied and distributions were established. The maximum of the small structure (size less 50′′) distribution at low latitudes takes place during minimum activity. The distribution of small features drifts from the middle latitude to poles in the period from the beginning of the activity of the cycle up to magnetic field reversal of the poles and from the pole to the equator after the reversal. For large structures the distribution reflects the activity of sunspots. Filaments drift to the poles in the epoch of magnetic reversal.