What Causes Wind And Pressure Systems?
Uneven heating creates differences in air pressure, and air is pushed from high pressure toward low pressure. Earth's rotation bends that moving air through the Coriolis effect, so wind circles highs and lows instead of blowing straight in. The same physics builds the jet stream aloft and local winds like the sea breeze.
Air is lazy until something pushes it. This unit is about the pushing. We start with the forces behind every breeze, read the H and L on a weather map, climb up to the jet stream, then come back down to the sea breeze that sets off Florida's afternoon storms.
What You’ll Learn
- How the pressure gradient force, the Coriolis effect and friction shape the wind
- Why lows bring clouds and storms while highs bring clear skies
- How to read isobars, troughs, ridges and station plots on a surface map
- What the jet stream is and how it steers storms
- How the Hadley, Ferrel and Polar cells organize global winds
- How sea breezes, chinooks, katabatic winds and mountain waves form
Lessons In This Unit
- 3.1What Makes The Wind Blow: Pressure Gradient And CoriolisWind blows because air is pushed from high pressure toward low pressure by the pressure gradient force. Earth's rotation then bends moving air, to the right in the Northern...Intermediate · 9 min
- 3.2Highs, Lows, Troughs And RidgesLow pressure means air near the ground converges and rises, cooling into clouds, rain and stronger winds. High pressure means air sinks, warms and dries, which usually brings...Beginner · 9 min
- 3.3The Jet Stream And The Global CirculationThe jet stream is a narrow band of very fast west-to-east wind near the top of the troposphere, roughly 9 to 14 km up. It forms where warm and cold air meet and the temperature...Intermediate · 10 min
- 3.4Local Winds: Sea Breezes, Mountain Winds And MoreA sea breeze forms on sunny days because land heats much faster than water. Warm air over land expands upward and spreads seaward aloft, lowering surface pressure over the...Intermediate · 10 min
Questions People Ask
Why does wind blow?
Air is pushed from high pressure toward low pressure by the pressure gradient force, then turned by the Coriolis effect and slowed by friction near the ground.
Which way does wind go around a low?
Counterclockwise and inward in the Northern Hemisphere, and clockwise in the Southern Hemisphere.
What is the jet stream?
A narrow band of fast west-to-east wind near the top of the troposphere that forms along strong temperature contrasts and steers storms.
By the end of this unit, the wind will stop being random and start being a story. — Jen
