Wind is caused by pressure gradients, which are horizontal differences in pressure across an area. Wind patterns range in scale from global, which are generally persistent, to local and short duration, such as thunderstorms.
Wind has a great influence on coastal geomorphology, both directly and indirectly. The direct influence includes wind as an agent of erosion and transportation. It affects the coastal zone by eroding, transporting, and subsequently depositing sediment. Two coastal geomorphic features that are a direct result of wind are dunes and blowouts.
Dunes are depositional features whose form and size are a result of sediment type, underlying topography, and wind direction, duration, and strength. Blowouts occur when wind erodes an unvegetated area, thus removing the sand and leaving a depression or trough.
Wind indirectly affects coastal geomorphology as wind stress upon a water body causes the formation of waves and oceanic circulation. Winds are a defining component of storms, which produce waves and surges that transport sediment and can damage upland developments. Wind also moves sea ice onto the coast in certain northern regions. Although this is an indirect process, the impact of wind-induced water movement is very significant to coastal areas.