The phrase “nonlinear tides” does not correspond to a distinct, widely recognized entry in major encyclopedic references. Consequently, comprehensive, independently verified encyclopedic information on the term is lacking.
Possible interpretation
In physical oceanography, tides are often analyzed using linear theory, which assumes that tidal motions can be represented as a superposition of sinusoidal components (harmonics) that do not interact. However, real oceanic tides can exhibit non‑linear behavior when tidal currents become sufficiently strong or when they interact with bathymetric features such as shallow shelves, continental slopes, or coastal geometry. The resulting phenomena are sometimes described informally as “nonlinear tides.” Typical manifestations include:
- Generation of overtides (higher harmonics) – Energy transfer from the principal tidal constituent to its integer multiples (e.g., M4, S6) caused by nonlinear advection and friction.
- Tidal asymmetry – Differences between flood and ebb phases, often observed as steeper leading edges of tidal waves.
- Internal tidal solitons and tidal bores – Nonlinear waveforms that propagate within stratified water columns or along river mouths.
- Triadic and resonant interactions – Coupling among tidal constituents and between tides and other oceanic waves (e.g., Rossby or Kelvin waves).
Research literature on ocean dynamics frequently discusses these processes under headings such as “nonlinear tidal processes,” “tidal overtides,” or “nonlinear tide–current interactions,” but they are not consolidated under a single encyclopedic article titled “Nonlinear tides.”
Conclusion
While the concept of nonlinear effects in tidal dynamics is well established within the scientific community, the specific term “nonlinear tides” lacks a dedicated, widely recognized encyclopedic entry. Accordingly, only a brief contextual description can be provided.
