The semi-diurnal tides along the equator in the Indian Ocean

Abstract

The distribution of the semi-diurnal tidal constituent K 2 along the equator has been calculated with the aid of known harmonic constants at approximately fifty coastal stations in the northern part of the Indian Ocean. This has been achieved by use of a theorem in tidal dynamics, which connects integrals involving the tidal elevations and currents along the boundaries of an oceanic region and the equilibrium elevation over its surface. The distribution of K 2 along the equator has been obtained in the form of a Fourier cosine series. The depth of the ocean has been taken as uniform, except where corrections have been applied to the tidal data in areas where the water is very shallow. In the equatorial distribution the variations of phase give supporting evidence for recent co-tidal charts of the ocean. In addition, however, an estimate for the amplitude of the constituent is given for any point on the equator. This is believed to be the first direct arithmetical calculation of oceanic tidal distribution.