The Magnetic Disturbance Field at Kodaikanal

Abstract

The magnetic disturbance field at Kodaikanal has been studied, using the data. for the period March 1950 to February 1954. As far as the horizontal magnetic field is concerned, it is found that the form of the disturbance daily variation does not depend on the degree of disturbance. During equinoxes and winter solstices, the disturbance vector, BD is at right angle to the Bg vector (quiet day diurnal variation) and is at an obtuse angle to the Bg vector during summer solstice. Hence with increasing disturbance there is a pronounced variation of the phase of B (diurnal variation) vector, but the variation in its amplitude is small. This suggests that the phase, rather than the amplitude of the variation may be a better criterion for determining the intensity of a disturbance. It is also noticed that the storm time field too retains its form at various levels of disturbance. The variation in the vertical force is found to be too small to give any significant results.