The coastline generally represents a marked discontinuity in surface roughness. The resulting mechanical forcing leads to a secondary circulation in the boundary layer, leading to localised vertical motion which may, in turn, have a strong influence on weather in the coastal zone. This conceptual model describes a flow in which friction is the main driving force for cloud development. In contrast Stau Cloudiness and Lee Cloudiness conceptual models describe circulations primarily caused by more distinct orography (mountains and hills). It has to be kept in mind, however, that other factors besides friction, such as the differential heating between land and sea or the topography and shape of the coast have a marked influence on the dynamics of Coastal Convergence. Purely thermally driven circulation on the coast is called the Sea-Breeze. The most intensive Coastal Convergence by friction is induced when the wind blows parallel or in small angle onshore, the lower pressure being to the left of the wind component parallel to the coast.
Filed under Keywords:
Conceptual Models, Synoptic Scale Meteorology, Ocean, Sea