global atmospheric circulation Flashcards
what is wind
the movement of air from high to low pressure. The greater the difference in pressure, the stronger the wind
how does global atmospheric circulation lead to high and low pressure belts
warm air rises, creating a low pressure belt and cooler air sinks creating a high pressure belt
what creates a low pressure belt with rising air
the sun warms the earth, which transfers heat to the air above , causing it to rise
as air rises what happens
it cools and moves out to 30 degrees Celsius north and south of the equator
what happens when the cool air reaches the ground surface
either back to the equator or towards the poles
what are trade winds
surface winds blowing towards the equator
how are clouds formed
trade winds blow from south east from north east. At the equator these trade winds meet and are heated by the sun, which causes them to rise and form clouds
what are Hadley cells
the largest atmospheric circulation cell which causes heavy rain
what is meant by insolation
the amount of heat from the sun that reaches the earth’s surface
what is the prevailing wind
wind from the most common direction in any given place
what is the albedo effect
the amount of surface area reflects the sun’s rays back into space
what is precipitation and give examples
any moisture falling from the atmosphere
eg. rain, hail, sleet and snow
what causes precipitation
warm air containing water vapour rises, cools and condenses into clouds
what is a jet stream
very strong wind high in the atmosphere
what are polar climate zones
temperatures are low all year round
what are temperature climate zones
moderate summers and winters. Low pressure causes by rising air from 2 cells meeting, rainfall is frequent
what are tropical climate zones
temperatures are hot all the time and rainfall is high.
what are arid (dry( climate zones
rainfall is very low most of the year. temperatures are hot/warm. sinking air from 2 cells meeting causes high pressure and prevents rainfall
