Circulations of air common along coasts, caused by a low-level pressure gradient due to the differential heating of land and sea. On summer days, solar radiation warms the land surface more strongly than the adjacent sea: a pressure gradient from sea to land results in a gentle, cooling, landward ‘sea breeze’ whose maximum strength is usually developed by late afternoon. Upward movement of warm air over the land and movement toward the sea at greater height, followed by subsidence, produces a shallow convection cell. At night and in early morning cooler land and relatively warmer sea produce a reverse-flow convection cell, with a seaward ‘land breeze’. The horizontal extent of well-developed land and sea breezes is typically limited to about 40 km from the coast, but associated air movements can often be detected over a much wider coastal belt.
Subjects: Ecology and Conservation — Earth Sciences and Geography.