Global Atmospheric Circulation

What is global atmospheric circulation?

The movement of air around the atmosphere to redistribute heat.

What is the formula for global atmospheric circulation?

Latitude + solar energy + air pressure = air movements around the world.

What is latitude?

Coordinates going from North to South specifying point on Earth from 0-90, with 0 being the equator and 90 being North and South Pole.

How does latitude correlate with the temperature?

A lower latitude leads to a warmer temperature.

How does latitude aid atmospheric circulation?

The latitude changes the solar energy through the angle of incidence.

At 0 there is a small angle of incidence therefore solar energy spreads over a small area making it more concentrated.

At 90 there is a large angle of incidence therefore solar energy spreads over a large area making it less concentrated. Due to the curvature of the Earth.

How does the distance aid atmospheric circulation?

The atmosphere thickness stays the same all round.

At the equator, solar energy travels a shorter distance through the atmosphere therefore there is a low chance of solar energy being rejected by clouds and gases back to space.

At the poles, solar energy travels a longer distance through the atmosphere therefore there is a high chance of solar energy being rejected by clouds and gases back to space.

What is atmospheric pressure?

The weight of the air, and the force it exerts on the ground.

When air is heated, it increases energy in the air making it less dense, therefore it rises. So there is lower pressure on the ground.

When air is cooled, its denser therefore it sinks and exerts more force on the ground. So there is a higher pressure on the ground.

How do convection currents work?

1. Ground heats up air above it (infrared)

2. Therefore hot air is less dense so it rises.

3. Air is far away from the ground so it cools down

4. Therefore cold air is denser so it sinks

How do convection currents affect global atmospheric circulation?

They facilitate the transfer of heat from warmer, denser regions to cooler, less dense areas.

How does the sun heat up our Earth?

The sun doesn’t directly heat the Earth, (as UV is bad at heating air) instead the ground does:

• Short wave radiation (UV) is emitted from the sun that shines onto the ground

• The ground absorbs it and repels it in long wave radiation (infrared) heating the air.