Analysis of Records of Currents
Different methods of representing surface currents are discussed on pp. 427–430. For currents of a periodic character, it is convenient in most cases to compute the north-south and east-west components of the currents or the components referred to some other coordinate system, say parallel to and at right angles to the coast. The components can readily be subjected to harmonic analysis or to other forms of statistical treatment, subsequent to which the results can be represented in a simple manner (see fig. 145, p. 573). Harmonic analysis has been widely applied and is a very useful tool (see Thorade, 1933).