Uneven heating of the Earth’s surface causes winds. On being heated, the air becomes lighter and rises. As a result, a region of low pressure is created. Then, air from a high-pressure region moves to a low-pressure region, causing wind.
- Wind’s speed is determined by how much of a pressure difference exists. The bigger the difference between the pressures, the faster the air rushes toward the low pressure.
- As the wind blows, several things can interrupt air’s motion and make its speed vary, such as trees, mountains, and buildings.
- Whenever air is obstructed in this way, friction (a force that opposes motion) increases, and wind’s speed slows.
- Meteorologists also use wind measurements to tell how fast weather systems are moving, which allows them to forecast