Tidal Constituent
D2. Hydrography, tides, waves, bathymetry and marine geologyDefinition
Sinusoidal component of the tide such as M2, S2, K1, or O1.
A tidal constituent is a single periodic component of the tide arising from one combination of the orbital motions of the Earth, Moon, and Sun, such as M2, S2, K1, O1, N2, and the shallow-water overtides M4 and MN4. The semidiurnal band clusters near 12 hours, the diurnal band near 24, with long-period (fortnightly, monthly, annual) and shallow-water harmonics besides. Summed at their local amplitudes and phases they reconstruct the tide.