Local Winds Flashcards
What are Local winds and what category of atmospheric circulation do they occur?
Local winds, which occur on a smaller scale than the global and regional patterns just discussed, belong to the tertiary category of atmospheric circulation. Land and sea breezes are local winds produced along most coastlines
What are land and sea breezes?
Wind along coastlines and adjoining interior areas created by different heating characteristics of land and water surfaces—onshore (landward) breeze in the afternoon and offshore (seaward) breeze at night.
How is a sea breeze formed?
The different heating characteristics of land and water surfaces create these breezes. Land gains heat energy and warms faster than the water offshore during the day. Because warm air is less dense, it rises, creating a lower-pressure area that triggers an onshore flow of cooler marine air to replace the rising warm air—the flow is usually strongest in the afternoon, forming a sea breeze.
Explain the nighttime land-breeze pattern.
At night, land cools, by radiating heat energy, faster than offshore waters do. As a result, the cooler air over the land subsides (sinks) and flows offshore toward the lower-pressure area over the warmer water, where the air is lifted. This nighttime land-breeze pattern reverses the process that developed during the day.
What are Mountain and valley breezes
Mountain and valley breezes are local winds resulting, respectively, when mountain air cools rapidly at night and when valley air gains heat energy rapidly during the day
A light wind produced as cooler mountain air flows downslope at night and as warmer valley air flows upslope during the day.
How do mountain and valley breezes work during the day/night?
Valley slopes are heated sooner during the day than valley floors. As the slopes heat up and warm the air above, this warm, less-dense air rises and creates an area of low pressure. By the afternoon, winds blow out of the valley in an upslope direction along this slight pressure gradient, forming a valley breeze. At night, heat is lost from the slopes, and the cooler air then subsides downslope in a mountain breeze.
What are Katabatic winds?
Katabatic winds
Air drainage from elevated regions, flowing as gravity winds. Layers of air at the surface cool, become denser, and flow downslope; known worldwide by many local names.
What is the Mistral?
The mistral of the Rhône Valley in southern France is a cold north wind that can cause frost damage to vineyards as it moves over the region on its way to the Gulf of Lion and the Mediterranean Sea.
What is the Bora?
Bora, driven by the cold air of winter high-pressure systems occurring inland over the Balkans and southeastern Europe, flows across the Adriatic Coast to the west and south.
What are the chinook winds?
In western Canada and the U.S. West, chinook winds are dry, warm downslope winds occurring on the leeward side of mountain ranges such as the Rockies in Alberta and Montana or the Cascades in Washington.
