What is global atmospheric circulation? Flashcards
What is atmospheric pressure?
The force exerted by on the Earth’s surface by the weight of the air above it.
What is standard pressure at sea level?
1013 mbar.
What is estimated to be low pressure?
970 mbar
Where does air move from?
From high pressure to low pressure.
Movement creates weather and wind changes.
What is pressure shown on a map as?
Isobars.
What can be measured from wind?
Wind direction and wind speed.
What is the tricellular model of Atmospheric circulation?
It is a model displaying how air rises and sinks in the atmosphere.
What is the Hadley cell?
The hadley cell is the first cell. It starts when the equator is hot, when air rises and creates a low pressure zone. The air moves away fron the equator and sinks back to the earth’s surface around 30 degrees latitude. Forms high pressure many hot desertsThe Hadley Cell is the initial cell. This begins at the Equator, where temperatures are quite high. Warm air rises and creates a region of low pressure. At about 30 degrees latitude, the air flows away from the Equator, cools, and sinks back towards the surface of the Earth. Many of the world’s hot deserts are formed by this high-pressure zone.
What is the ferrel cell?
The Ferrel Cell is the second type of cell. The Westerlies are produced when air close to Earth’s surface flows poleward from a high pressure area to a low pressure area. At about 60 degrees latitude, this comparatively warm air mass begins to rise above the colder air as it encounters frigid Polar winds from the north, creating another area of low pressure.
What is the polar cell?
The Polar Cell is the last type of cell. These are found near the poles and are created when an area of high pressure is created at the North and South Poles by the sinking of cold, dense air. As it moves towards lower latitudes, the frigid air radiates out from the poles. At about 60 degrees latitude, the air starts to rise as it mixes with warmer air from lower latitudes.
