Science Common Sense

1299 - Why does the rotation of the Earth cause the rotation of air in high and low pressure systems?

Imagine you're spinning around in a circle with a ball. If you throw the ball straight ahead, it doesn't just go straight - it's also curved a bit to the right or left because of the spin.

The same thing happens with air on Earth. Earth is spinning, and when air moves, it also gets an extra push because of Earth's spin. This is called the Coriolis effect.

In low-pressure systems, air moves in, and because of the Coriolis effect, the air gets pushed around the low pressure in a spiral. In the Northern Hemisphere, the air spins counterclockwise, and in the Southern Hemisphere, it spins clockwise.

In high-pressure systems, air moves out, and the Coriolis effect makes it curve, creating a different spiral shape. That's why air moves in spirals in both low and high-pressure systems, because of the Earth's spin.