A diagram of a body of water surrounded by mountains and a drawing of a sun above.

• Radiation- Much of the sun’s radiation reaches Earth’s surface, where it heats the land and water. Land and water radiate heat back into the atmosphere.
• Conduction- The conduction process transfers heat from land and water directly to the few meters of air nearest Earth’s surface.
• Convection- Convection moves heat through the troposphere. As surface air is heated by radiation and conduction, rising warm air is replaced by denser, downward-flowing cool air.