Component 1 - Topic 1: Hazard Earth: 1.1 Global Circulation Flashcards
Where on earth’s surface most radiation is recieved?
Towards the equator or towards the poles
Why does the equator and poles recieve the most solar radiation?
Equator: hottest part of the earth, the sun’s
concetrated iver a small area and strike at a right angle
Poles: reach the surface at a lower angle so the same radiation has to heat up at a larger surface
What is the Earth’s axial tilt
Called the obliquity, changes angle with time about 41,000 years from 22.1° to 24.5° the angle increases the temp and decreases
What is the earth’s procession?
Earth’s spinning top that slows down caused by gravitational pull of the moon and sun. Moving around in a circle
What is it meant by low pressure?
When air is heated making it less dense transffering heat to the atmosphere cools and condenses usually kforming rain
Why does low pressure occur?
Because there is less air as the surface meaning low pressure
What is it meant by high pressure?
When air cools it condenses meaning no heat is transmitted into the atmosphere but into the ground having no clouds/ rainfall
Why dies high oressure occur?
Because there is more air meaning there is high pressure
What is atmospheric pressure?
The ‘weight’ of the air and the force it exerts on the ground. It impacts the climate
How does high and low pressure explain wind pressure?
Winds are caused when ar moves from high to low pressure because of the earth’s rotation the wind is deflected to the right in the northern hemisphere and left in the southern hemisphere this is called the corriolis effect
How heat transferred by ocean currents?
- are deep ocean currents driven by differences in water density
- this warmer water is cooled and sinks, continuing the cycle
- When water freezes at the poles water gets saltier increasing density
Example countries for global atmospheric circulation?
- algeria
- singapore
How does atmoshperic circulation cause high pressure?
As air sinks in it becomes denser and oressure increases warming up and drying which stops any remaining moisture in the air condensing (no clouds)
How does atmospheric circulation cause low pressure?
As air rises it exapnds and becomes less dense causing low pressure rising moisture-heavy air causing thunderclouds
What is the arid climate zone?
Sinking air from the hadley and farrel cells meeting causes high pressure preventing rainfall meaning it is low and temperatures are hot or warm
