%0 Book Section %T Ocean tide models of M2 and S2 constituents for the western and central Mediterranean sea publisher Politecnico di Milano . Dipartimento di Ingegneria Idraulica, Ambientale e del Rilevamento %D 1993 %@ https://hdl.handle.net/20.500.14352/60636 %X In this paper we describe the modellinng of the M2 and S2 constituents for the Western and Central Mediterranean Sea, based on mareographic observations. The evaluation of the time variations of the sea surface topography is also studied in order to obtain the corrections necessary for the approximation of an ideal mean level corresponding to the equilibrium surface of an ocean without perturbations. %~