Third order effects in the tide of the Pacific, near Acapulco

Abstract

Vertical oscillations, attributable to the third order term of the potential of the tide-generating forces, are conspicuous in the semidiurnal band, near the frequency of L 2, in water level records from Acapulco on the Pacific coast of Mexico and at other sites. Since the relative magnitude of the third order contribution can only be derived from similar observations at any gauging site, it is not possible to take into account third order inputs in conventional nodal corrections.