Tides are a result of the gravitational attraction of the Moon and Sun on the Earth and ocean.
Tidal forces are a result of small gradients in the gravitational field. Tidal dynamics can be viewed in two reference frames: a non-inertial (accelerating) rotating frame relative to the center of mass of either the Earth-Moon or Earth-Sun systems, or the inertial non-rotating frame of reference (i.e. fixed with respect to the stars).

In the Earth-centric non-inertial reference frame, the net tidal forces can, for interpretation purposes, be divided into two parts; the gravitational...
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