How Air Moves Around the Planet
Your troposphere (the bottom layer of atmosphere where all weather happens) works like a giant conveyor belt system with three main loops called cells. These cells create predictable wind patterns that sailors and pilots have relied on for centuries.
Here's how the system works: Hot air at the equator rises up, creating low pressure and loads of rain. This air then travels towards 30°N and 30°S, where it cools down and sinks, forming high pressure belts with clear, dry conditions - perfect for deserts like the Sahara.
The trade winds blow from these high pressure areas back towards the equator, whilst the westerlies blow towards the poles. These aren't random - they follow the same patterns year after year because of Earth's rotation and temperature differences.
Low pressure belts mean rising air, clouds, and rain (think tropical rainforests). High pressure belts mean sinking air, clear skies, and dry conditions (think major deserts). Understanding this pattern helps explain why certain climate zones exist where they do.
Remember This: Low pressure = lousy weather (rain), High pressure = happy weather (sunshine)!