Air Pressure and Wind
Air flows from high to low pressure.
About this topic
Air pressure is the weight of air pressing on a surface, about 1013 hPa at sea level, measured with a barometer. Warm air rises, creating low pressure; cool air sinks, creating high pressure. Wind is air moving from high to low pressure, and the greater the pressure difference, the stronger the wind.
The Coriolis effect, due to Earth's rotation, deflects winds right in the Northern Hemisphere and left in the Southern, so winds spiral around highs and lows. Sea breezes arise from uneven heating of land and water.
A pressure difference of just 4 hPa between two places 100 km apart is enough for a brisk breeze, and a mature hurricane may have a central pressure below 950 hPa. On a hot day at the coast, the land warms faster than the sea, so air rises over the land, drawing a cooler sea breeze inland; at night it reverses into a land breeze. In the Northern Hemisphere, air spirals counter-clockwise and inward around a low, and clockwise and outward around a high; in the Southern Hemisphere it is reversed.
Pilots, sailors, wind farm designers and kite surfers all depend on understanding wind. Buys Ballot's law says that if you stand with your back to the wind in the Northern Hemisphere, low pressure is on your left. Barometers falling quickly warn of storms, and rising ones signal improving weather. A common misconception is that air pressure pushes only downward; it acts equally in all directions, and a bubble of air in your body is balanced. Another is that wind blows straight from high to low; the Coriolis effect and friction make it curve.
Key ideas
- Winds are pressure-driven
- Coriolis effect turns them
- Fronts form where air masses meet
Quick check
Use cases: where Air Pressure and Wind helps
- Homework: review the key idea behind Air Pressure and Wind before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Air Pressure and Wind without notes.
- Visual learning: play with the interactive lab to see how Air Pressure and Wind changes when you adjust its inputs.
- Teaching a friend: explain Air Pressure and Wind in your own words, then compare your version with the key ideas.
Earth science helps with weather forecasts, natural hazards, energy and climate planning.
Frequently asked questions
What is Air Pressure and Wind?
Air flows from high to low pressure.
What will I learn in Air Pressure and Wind?
Winds are pressure-driven. Coriolis effect turns them. Fronts form where air masses meet.
Is Air Pressure and Wind part of Earth & Space?
Yes. It is one of 60 Earth & Space topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Air Pressure and Wind lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Air Pressure and Wind?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.