3.1 Global atmospheric Circulation Flashcards
Explain solar insolation
The sun is the most intense at the Equator, e.g Gabon in Africa at 0 degrees latitude
As latitude increases rays of sun are spread more thinly, eg Arctic Circle
Explain jet streams
High altitude currents of air created by the Earth spinning on its axis.
These interact with the convection cells e.g Hadley and Polar cells
The exact position of these varies annually due to the Earth being tilted
What is the polar cell
60 - 90 degrees. Air rises at 60 degrees and falls at 90 degrees. There is low solar radiation so it is cold
What is the Hadley Cell
TRF, Savanna, Desert
0-30 degrees. Air rises at the equator and falls at the desert.
Rising air cools, condenses and precipitates. Falling air is dry
What is the ITCZ and explain
Tropical storms
This is located around the equator and as warm air rises it can create bursts of torrential rainfall.. The ITCZ can form a wave of low pressure which extends out to the tropics and is responsible for tropical storms
What is the Ferrell Cell
30 - 60 degrees
This is where the UK is located in the mid-latitudes. Air rises at 60 and falls at 30.
Air from the poles and tropic meet here
Give examples of places with low pressure
TRF
- rising/ascending air
- air carries water vapour
- clouds and rain
Give examples of places with high pressure
Desert
- Sinking/descending air
- dry with no clouds
What happens in the Hadley cell
- Air rises at the equator, it carries water vapour that has been evaporated by the heat from the sun
- The coriolis effect forces it to move north or south of the equator
- The water vapour condenses when it rises, leading to heavy rainfall in the Tropics
The air moves towards the edge of the Tropics - The north easterly and south easterly tradewinds support this movement
- At the edge of the Tropics, the air sinks, the climate is hot and dry, desert
What are jet streams
High altitude currents of air created by the earth spinning on its axis
