Optical Aspects of Solar Activity

Abstract

A review of optical observations of some solar phenomena is presented. From the photospheric observations of the birth, growth and decay of pores, spots and sunspot groups and associated velocity and magnetic field structure have been discussed. Some dynamic phenomena associated with sunspots are also discussed. High resolution H-alpha chromospheric observations offer remarkable advantage to understand the evaluation of solar activity and the associated magnetic field development and decay. A recent observations show evidence of emergence and submergence of magnetic flux tubes. Piddington's (1976) model of twisted flux ropes seems to explain the observed emergence and submergence of field and moving magnetic features. Chromospheric velocity oscillations and wave motion observations in sunspots are discussed.

It will be difficult to discuss all the optical aspects of solar activity in this short review talk. Hence, I shall confine only to some aspects concerning the birth, growth and decay of active regions.