Editing Tide (section)

=== Laplace's tidal equations ===
Ocean depths are much smaller than their horizontal extent. Thus, the response to tidal forcing can be [[Model (abstract)|modelled]] using the [[Laplace's tidal equations|Laplace tidal equations]] which incorporate the following features:

* The vertical (or radial) velocity is negligible, and there is no vertical [[wind shear|shear]]—this is a sheet flow.
* The forcing is only horizontal ([[tangent]]ial).
* The [[Coriolis effect]] appears as an inertial force (fictitious) acting laterally to the direction of flow and proportional to velocity.
* The surface height's rate of change is proportional to the negative divergence of velocity multiplied by the depth. As the horizontal velocity stretches or compresses the ocean as a sheet, the volume thins or thickens, respectively.

The boundary conditions dictate no flow across the coastline and free slip at the bottom.

The Coriolis effect (inertial force) steers flows moving towards the Equator to the west and flows moving away from the Equator toward the east, allowing coastally trapped waves. Finally, a dissipation term can be added which is an analog to viscosity.