The influence of polarity separation on the daily tilt angle variation of sunspot groups has been studied from a selected number of observations of the Sun spanning the entire 22nd solar cycle. Daily white-light images of ...

Kodaikanal H-alpha monochromatic and white-light observations are used to study the circular flare of 14 March, 1984. We report here the dynamic activity of the H-alpha filament, which attained a severe twist before erupting ...

The poleward migration-trajectory diagram of filament bands is derived for the years 1915-1982 from the H-alpha synoptic charts. The global solar activity commences soon after the polar-field reversal in the form of two ...

Poleward migration of the magnetic neutral line on the sun has been computed for the period 1904-1940 using synoptic charts based on H-alpha observations and the epochs of sign reversal of the solar magnetic field at ...