Atmospheric Pressure *G11 Flashcards
What is atmospheric pressure
The weight of the atmosphere on earth’s surface
Differences in temperature create *a
*a causes *b
*b forms *c
*3
a = differences in atmospheric pressure
b = air movement
c = global air circulation
Explain how low pressure area is formed and what does this conclude*2
*high temperatures cause air to expand and rise
*therefore there is an area of converging air
Explain how high pressure area is formed and what does this conclude*2
*low temperatures cause air to contract and sink
*therefore divergence occurs
Dew point definition
Temperatures which water vapour starts to condense
🏔️ITCZ definition
Intertropical convergence zone = zone when two sets of tropical easterlies converge
Where are Hadley cells found
Between equator and 30*N/S
Explain the Hadley cell *4
*equator is hot as a result of receiving Direct Sunlight
*the warm air rises, cools and becomes dense
*the cold dense air sinks back to the surface
*the air heats as it gets closer to the surface, condensation occurs then it rains
Where are Ferrell cells found
Between 30N/S and 60N/S
(Hadley and polar cells)
Explain Ferrell cell *2
*warm air is transferred to high latitudes
*cold air shifts to subtropics, it is then warmed
When is the polar cell found
Between 60 and 70*N/S and the poles
Explain the polar cell *3
*cold air sinks over high latitudes and shifts to lower latitudes
*air warms up eventually
*the warm air rises and cools in the upper atmosphere
Give characteristics of easterly winds *4
*going west from east
*winds from subtropical to equator
*cools regions
*surface winds of Hadley cells
Give characteristics of westerly winds *4
*going east from west
*winds form at subtropical to subpolar regions
* warms regions
*surface winds of Ferrell cells
