Where does wind come from? I thought it came from clouds but I’ve just had two really windy days with no clouds in sight
In: Earth Science
On the global scale winds is caused by the difference in solar heating and earth rotation.
Hot air expands and the density decrease. Colder is around can then come in from the sider and lift the warmer air up. This is why hot air balloons can fly and why hot air rises over candles etc.
Land and water heat up at different rates. The same is the case for different types of land like forest vs grassland. Th polar region gets less sunlight than the equator. So
This effect result directly in sea breeze where the land gets hotter than the water in the sun and you get a breeze from the water towards land. During the night the land can cool down fast and the water is not warmer so cooler air moves out from land to the sea.
Earth rotation can cause more wind when there is some moment in the air toward or away from the poles. The ground on the equator has to move faster than on the poles to rotate once per day. So move 1670 km/h (1000mph) but on the poles, the tangential speed is zero.
So the air that moves away from the equator moves slightly faster than the ground below it and wait that move towards the equator move slightly slower.
This is a major part of why hurricanes and other weather phenomena rotate. The rotation direction is always the same on the north side of the equator and the opposite south of it.
So it is not clouds but solar heating and earth rotation on a local and global scale.
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