Zeewinden

Zeewinden, typically translated as sea winds, are winds that originate over the sea and blow toward the land along coastlines. They are a key feature of coastal meteorology and result from thermal and pressure differences between the sea surface and adjacent land.

Formation and cycle: During daytime, solar heating raises the land surface temperature more than the adjacent sea, creating a shallow circulatory cell near the coast. Air rises over the land, and cooler air from the sea moves inland at low to moderate heights, producing onshore flow known as the sea breeze. At night, the land cools faster than the sea, which can weaken the onshore flow or reverse it to an offshore wind, commonly called a land breeze. The strength and depth of zeewinden depend on coastline geometry, humidity, and regional temperature contrasts.

Characteristics and effects: Zeewinden are usually light to moderate, commonly in the range of 5 to 25 km/h, but can exceed 40 km/h under strong thermal forcing or pressure gradients. They moderate coastal temperatures, increase humidity near the shore, and influence cloud development along the coast. The convergence between onshore flow and inland air can trigger shallow clouds or localized thunderstorms during warm seasons.

Regional variation and measurement: The presence and strength of zeewinden vary with geography—coastal shape, bays, and peninsulas—alongside sea surface temperatures and larger-scale weather patterns. They are monitored by coastal weather stations, buoys, ships, and satellites, and forecast by numerical weather prediction models that incorporate sea–land interactions.