Hazardous Earth Flashcards
Explain atmospheric circulation.
The sun heats up air in the Earth’s atmosphere. The temperature of the Earth’s atmosphere depends on latitude. As the Equator is closest to the sun, the air here is warm and air at the North & South Pole is cold.
The atmospheric circulation is…..
the movement of air around the earth to try and balance temperature.
What is air pressure?
High pressure = lots of air pushing on the floor.
Low pressure = not much air pushing down at the ground.
What is the pressure like when warm air rises?
Low pressure.
What is the pressure like when cool air sinks?
High pressure.
Explain global circulation : The three cell model.
Warm air rises at the equator and travels to around 30 cellcuis North where it cools and sinks to the surface, before returning to the tropics. This movement is known as the HADLEY CELL.
At the equator there is an area of low pressure, due to the rising and expanding of air. At around 30 cellcuis North the sinking air creates an area of high pressure.
The FERREL CELL is found between the Hadley and Polar cells and lies between 60 cellcuis North and 30 cellcuis North. The POLAR CELL is much smaller. Cold air sinks at the North Pole, before flowing south at the surface. Here it is warmed by contact with land/ocean around 60 cellcuis, where it rises creating a low pressure area.
Define the Coriolis force.
Apparent force, due to the spinning of the Earth, which deflects movement of particles and wind.
Define oceanic circulation.
Heat from the tropics can be transferred to the cold polar regions, by large-scale water movement within the oceans. Each ocean has its own circular pattern of currents. Heat is transferred by warm ocean currents, such as the North Atlantic Drift in the Atlantic Ocean, from low latitudes to high latitudes. Ocean currents are set in motion by the prevailing surface winds associated with the general atmospheric circulation. The direction of water movement is also deflected by the Coriolis force.
