Driftwind

In Azimuth's geography, Driftwind is the difference in global wind velocity at a given location from a set datum. Unless otherwise specified, that datum is the city of Nubylon, Azrune. Areas of the atmosphere with a low relative velocity are called Calms and are said to have low driftwind, whereas areas moving toward or away from Nubylon are called straits, oceans or seas. Due to a constant need to adjust positioning (or risk losing track of where they are), settlements are rarely built in high-driftwind areas.