Weather hazards Flashcards
Define Climate Zone
Climate Zones are divisions of the Earth’s climates into general climate zones according to average temperatures and average rainfall.
Define Solar Radiation
Solar Radiation is the sunlight and energy that comes from the sun and travels to Earth in the form of light waves.
Define Global Atmospheric Circulation
Global Atmospheric Circulation is the worldwide system of winds which transports heat from the tropics to the poles.
Define Inter-Tropical Convergence Zone
The Inter-Tropical Convergence Zone is the area near the equator where the north-east trade winds and the south-east trade winds come together.
Define Jet Stream
A Jet Stream is a fast-flowing (200km/hr) current of air that circles the planet at a height of 10km.
What does Global atmospheric circulation help to explain
Global atmospheric circulation helps to explain the location of world climate zones, as well as the distribution of weather hazards and global ecosystems.
Describe solar radiation
Heat from the sun is far more concentrated at the equator because it has less distance to travel and hits the ground almost at a right angle. The equator receives greater insolation (solar radiation).
Whereas in the North & South Poles the radiation has further to travel and is at more of an angle to the ground therefore less heating takes place.
How much sunlight at high latitudes compared to low latitudes
At high latitudes (N/S Poles) there is ‘thin’ sunlight while at low latitudes (equator) there is concentrated sunlight
What does warm air do
Warm air rises. Rising air gives low pressure. Rising air condenses forming clouds which causes rain
Clouds only form when warm air rises
What does cold air do
Cold air descends. Descending air gives high pressure. No clouds are formed meaning no rain.
Where are the Hadley, Ferrell and Polar Cells
Hadley Cell (0 to 30 degrees) N and S
Ferrell Cell (30 to 60 degrees) N and S
Polar cells (above 60 degrees) N and S
Polar cell Polar
Ferrell Cell Ferrel Hadley Cell Hadley
Equator
Hadley Hadley
Ferrell Ferrel
Polar Polar
Describe global atmospheric circulation (Equator (0°) to 30˚N and S)
Equator (0°) to 30˚N and S
Warm air rises at the equator and create thunderstorms
Low pressure forms in the Intertropical Convergence Zone (ITCZ) where the 2 cells meet over the equator
The air moves north or south and cools so sinks back to earth
When the air sinks it warms up and creates high pressure
When it gets to the ground it returns the equator as trade winds
Where are the Hadley, Ferrel and Polar Cells
Hadley Cell
Describe global atmospheric circulation (30° to 60˚N and S)
*30˚ to 60˚N and S
*Air on the surface moves to the poles to make warm winds in the north
*They meet the cold air from the poles at 60˚
*Warm air rises to form depressions
*Some air returns to the tropics and some joins the Polar cell
*The cell spins to the right in the north and the left in the south due to the earth’s spin (Coriolis effect)
Describe global atmospheric circulation (60° N and S)
*60˚N and S to the north pole and south pole
*Air sinks over the poles creating high pressure
*The air flows away from the poles and meets warm air from the Ferrell cell
