Convection Currents

• On our planet, air is always on the move.

• This movement is caused by changes in air pressure.

• Warmer, less dense air rises.

• Cooler, more dense air sinks.

• The sun's energy provides heat, but Earth does not heat evenly.

High-Pressure Systems

In a high-pressure system, the molecules of cooled air are dense and create "weight" that pushes the air down towards the surface of the Earth.

Low-Pressure Systems

In a low-pressure system, the warmed air molecules spread out, become less dense, and rise above Earth's surface.