Ocean surface wave in the context of "Breaking wave"

The surf zone or breaker zone is the nearshore part of a body of open water between the line at which the waves break and the shore. As ocean surface waves approach a shore, they interact with the bottom, get taller and steeper, and break, forming the foamy surface called surf. The region of breaking waves defines the surf zone. After breaking in the surf zone, the waves (now reduced in height) continue to move in, and they run up onto the sloping front of the beach, forming an uprush of water called swash. The water then runs back again as backwash. The water in the surf zone is relatively shallow, depending on the height and period of the waves.

In oceanography wind fetch, also known as fetch length or simply fetch, is the length of water over which a given wind has blown without obstruction. Fetch is used in geography and meteorology and its effects are usually associated with sea state and when it reaches shore it is the main factor that creates storm surge which leads to coastal erosion and flooding. It also plays a large part in longshore drift.

Fetch length, along with the wind speed (wind strength), and duration, determines the size (sea state) of waves produced. If the wind direction is constant, the longer the fetch and the greater the wind speed, the more wind energy is transferred to the water surface and the larger the resulting sea state will be. Sea state will increase over time until local energy dissipation balances energy transfer to the water from the wind and a fully developed sea results.

Swash, or forewash in geography, is a turbulent layer of water that washes up on the beach after an incoming wave has broken. The swash action can move beach materials up and down the beach, which results in the cross-shore sediment exchange. The time-scale of swash motion varies from seconds to minutes depending on the type of beach (see Figure 1 for beach types). Greater swash generally occurs on flatter beaches. The swash motion plays the primary role in the formation of morphological features and their changes in the swash zone. The swash action also plays an important role as one of the instantaneous processes in wider coastal morphodynamics.

There are two approaches that describe swash motions: (1) swash resulting from the collapse of high-frequency bores (${\displaystyle f>0.05\,\mathrm {Hz} }$) on the beachface; and (2) swash characterised by standing, low-frequency (${\displaystyle f<0.05\,\mathrm {Hz} }$) motions. Which type of swash motion prevails is dependent on the wave conditions and the beach morphology and this can be predicted by calculating the surf similarity parameter ${\displaystyle \epsilon _{b}}$ (Guza & Inman 1975):

In fluid dynamics, the wave height of a surface wave is the difference between the elevations of a crest and a neighboring trough. Wave height is a term used by mariners, as well as in coastal, ocean and naval engineering.

At sea, the term significant wave height is used as a means to introduce a well-defined and standardized statistic to denote the characteristic height of the random waves in a sea state, including wind sea and swell. It is defined in such a way that it more or less corresponds to what a mariner observes when estimating visually the average wave height.