Final answer:
Air sinks near the latitude 30° N and 30° S due to subtropical high-pressure belts, resulting in dry and clear conditions and the development of trade winds and polar easterlies.
Step-by-step explanation:
Air sinks near the latitude 30° N and 30° S due to the presence of subtropical high-pressure belts. These belts are caused by the descending air masses from the Hadley cells in the tropical regions. As the air descends, it becomes compacted and warms up, resulting in higher pressure at the surface.
This sinking air suppresses the formation of clouds and precipitation, creating dry and clear conditions. It also leads to the development of arid and semi-arid climates in regions such as the Sahara Desert and the Mojave Desert.
Additionally, the sinking air at these latitudes creates the trade winds as it flows towards the equator and the poleward flow of the polar easterlies in the upper atmosphere.
Learn more about Causes of air sinking near latitude 30° N and 30° S