Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
9 Cards in this Set
- Front
- Back
|
A huge body of air that has similar temperature, humidity, and air pressure at any given height is called an air mass.
|
Air Mass
|
|
|
Tropical, or warm, air masses form in the tropics and have low air pressure.
|
Tropical
|
|
|
Polar, or cold, air masses form north of 50° north latitude and south of 50° south latitude. Polar air masses have high air pressure.
|
Polar
|
|
|
Maritime air masses form over oceans. Water evaporates from the oceans, so the air can become very humid.
|
Maritime
|
|
|
Continental air masses form over land. Continental air masses have less exposure to large amounts of moisture from bodies of water. Continental air masses are dryer then maritime air masses.
|
Continental
|
|
|
The boundary where the air masses meet becomes a front.
|
Front
|
|
|
The warm air mass is cut off, or occulded, from the ground. As the warm air cools and its water vapor condenses, the weather may turn cloudy and rain or snow may fall.
|
Occulded
|
|
|
A swirling center of low air pressure is called a cyclone, from a Greek word meaning “wheel.”
|
Cyclone
|
|
|
As its name suggests, an anticyclone is the opposite of a cyclone. Anticyclones are high-pressure centers of dry air. Anticyclones are usually called “highs”—H on a weather map. Winds spiral outward from the center of an anticyclone, moving toward areas of lower pressure. Because of the Coriolis effect, winds in an anticyclone spin clockwise in the Northern Hemisphere. Because air moves out from the center of the anticyclone, cool air moves downward from higher in the troposphere. As the cool air falls, it warms up, so its relative humidity drops. The descending air in an anticyclone generally causes dry, clear weather.
|
Anticyclone
|
