The subtropical ridge is a large belt of high pressure situated around 30ºN in the Northern Hemisphere and 30ºS in the Southern Hemisphere. It is characterized by mostly calm winds. Air flows out from its center toward the upper and lower latitudes of each hemisphere, creating both the trade winds and the westerlies.

References

• Webster's Online Dictionary
• Physical Geography - The Global Environment
• Winds and the Global Circulation System

Tropical cyclones