Technical note: On seasonal variability of the M₂ tide

Seasonal variability of the M₂ ocean tide can be detected at many ports, perhaps most. Examination of the cluster of tidal constituents residing within the M₂ tidal group can shed light on the physical mechanisms underlying seasonality. In the broadest terms these are astronomical, frictional–advective interactions, and climate processes; some induce annual modulations and some semiannual, in amplitude, phase, or both. This note reviews how this occurs and gives an example from each broad category. Phase conventions and their relationship with causal mechanisms, as well as nomenclature, are also addressed.

R. D. Ray - Ocean Science, volume 18

On seasonal variability of the M2 tide - Technical note

Partager la page :

Spectrum of sea level at Saint-Malo, on the northern coast of France, focusing on the M2 group but with the central M2 constituent estimated and removed to better delineate the much smaller sidelines. The spectrum is based on 16 years of data. After spectral smoothing, the frequency resolution is approximately 0.2 cpy (or 0.0005 cpd), insufficient to clearly separate MSK2 from Γ2. The seasonal modulation of M2 at Saint-Malo is evidently dominated by the two frictional compound tides, although α2 is also imp
Spectrum of sea level at Saint-Malo, on the northern coast of France, focusing on the M₂ group but with the central M₂ constituent estimated and removed to better delineate the much smaller sidelines - The spectrum is based on 16 years of data - After spectral smoothing, the frequency resolution is approximately 0.2 cpy (or 0.0005 cpd), insufficient to clearly separate MSK₂ from Γ₂ - The seasonal modulation of M₂ at Saint-Malo is evidently dominated by the two frictional compound tides, although α₂ is also important – see the discussion in Sect. 3.2