Air quality - How does air pollution spread around the globe?
As air is heated up it rises, forming areas of low pressure, and as it cools it falls back down, forming areas of high pressure. The sun heats up the earth quicker than the oceans. This means that during the day the air over the land rises and to fill the gap, colder air is drawn in from the sea. This cooler air heats up, rises and more cool air is pulled in to fill the gap. As the air rises it cools and flows out to sea, creating an air current. At night the opposite happens. The earth cools faster than the sea, so the warm air above the sea rises pulling cool air off the land and creating an air current that flows in the opposite direction to the one during the day.
The differences in air pressure create wind events like hurricanes and cyclones.
If the earth didn't rotate, then air currents would travel from the equator to the poles in a relatively straight line. Because it does, the air north of the equator is deflected to the right and the air to the south of the equator is deflected to the left. This is called the coriolis effect.
All this happens in the ~10km (about 6 miles) above the earth's surface, a part of our atmosphere called the Troposphere. This is where all our weather happens. The Troposphere contains 75% of all the air and 99% of all the water vapour on earth.
Without wind there would be no weather.