Atmospheric Circulation and Weather Systems

Air movements are created by the uneven heating of the Earth’s surface. The Sun heats equatorial regions more than polar ones, so air near the ground’s surface expands and the pressure lowers.

This causes air to move away from the tropics towards higher latitudes, which results in warm air pushing cold air away.

Atmospheric pressure also determines when the air will rise or sink.

The wind redistributes the heat and moisture across the planet, thereby, maintaining a constant temperature for the planet as a whole. The vertical rising of moist air cools it down to form the clouds and bring precipitation.

All the energy in the atmosphere and on Earth is due to the sun’s radiation. Energy from the sun heats the earth and as a result there is heating on the surface of our planet, both land and sea.

Due to this heating on land and sea, we have variations in temperature and pressure on the surface of our planet giving rise to temperature inversion, i.e., temperature increasing with height rather than decreasing with height.

Inversions occur more frequently at night because there is no heat loss from the surface of the earth to space during darkness.