Theoretical variability of s1 in the tide generating potential

Abstract

The S1 tidal wave arising from the second order tidal potential occurs in any geophysical data record. Since the frequency of S1 is the same as that of earth’s rotation, many distortions are observed in real data sets. To isolate S1 from its powerful neighbours,K1 and P1 at least one-year hourly data series are required. Studies onS1 on an experimental basis, have been aimed mainly at a precise determination of its origin and mechanisms of variability. There are many hypotheses on its variability. In physical oceanography it is commonly accepted that the variability of S1 is due to air-sea interaction processes. The authors review most existing hypotheses on the variability of S1 They also show that the distortions of real data must be expected due to additional contributions from the second and third-order lunar potentials. An analysis is made to detect the sources of the additional contributions to the S1 frequency.