The path of a celestial body or an artificial satellite as it revolves around another body.

Carbon based, living materials that are capable of decay

A shift in position of various high and low pressure systems that in climate terms is usually defined as an index (i.e., a single numerically-derived number, that represents the distribution of temperature and pressure over a wide ocean area, such as the El Niño-Southern Oscillation, North Atlantic Oscillation, and Pacific Decadal Oscillation).

If wave runup exceeds the elevation of the dune, or in the absence of a dune, the beach berm, the system will be overtopped, transporting sand landward. Source: USGS