Things move, always. One of the driving forces to keep things moving on Earth is the unbalanced quantity of heat that falls on the planet. The equator receives more sunlight than the poles; the daytime side of the planet receives more sunlight than nighttime. Heat moves from warmer to colder, typically flowing from the tropics to polar regions. Earth never reaches a stable, uniform temperature. The flow patterns established by this constant heat transfer are the roots of circulation.
Naturally, there’s a lot more to it. Many factors affect circulation, from temperature to density to terrain. But the main point does not vary: systems out of balance seek an even level, while systems in balance are always knocked off kilter by outside forces. Here are a few examples featured in LOOP.
