Chapter 4 - Regional Wind Systems Flashcards
What are local winds caused either by?
Topographic effects or by variations in surface composition - land and water - in the immediate area.
What happens in coastal areas during the warm summer months?
Land surfaces is heated more intensely during the daylight hours than an adjacent body of water is heated.
By this, the air above land surfaces heats, expands, and rises, creating an area of lower pressure.
(At night, the roles reverse).
How does Sea breezes work?
In the morning:
The land warms and creates low air pressure.
The low air pressure rises and creates high cool air pressure.
The high cool air pressure then blows through the low air pressure in the atmosphere and then falls to the ocean.
The ocean then blows its air to the land.
The cycle then repeats.
How does land breeze work?
At night:
The ocean warms and creates low air pressure.
The low air pressure rises and creates high cool air pressure.
The high cool air pressure then blows through the low air pressure in the atmosphere and then falls to the land.
The land then blows its air to the ocean.
The cycle then repeats.
What is prevailing wind?
The wind that blows more often from one direction than from any other.
What is an anemometer?
An instrument that resembles a cup and is commonly used to measure wind speed.
What is an El Nino?
The name given to the periodic warming of the ocean that occurs in the central and eastern Pacific.
At irregular intervals of 3 to 7 years, the warm countercurrents become unusually strong and replace normally cold offshore waters with warm equatorial waters.
(Note: A major El Nino episode can cause extreme weather in many parts of the world.)
What is La Nina?
When surface temperatures in the eastern Pacific are colder than average.
This triggers a La Nina event that had a distinctive set of weather patterns.
(Think of it as the opposite of El Nino)
