Simply put, wind is the motion of the air around us, generated by differences in pressure in the Earth's atmosphere. Air is a fluid, and just like water, it obeys the laws of fluid dynamics. It will seek to flow from a region of higher pressure to one of lower pressure, says Chris Maier, a meteorologist with the National Oceanic and Atmospheric Administration’s National Weather Service.
Earth's air-filled atmosphere is constantly but unevenly pressurized, with highs and lows at various places caused by the uneven heating of Earth’s surface by the sun. The air at the North or South Pole is colder and denser, while the air at the Equator is warmer and rises more easily. The colder, more highly pressurized polar air is constantly trying to move down to the Equator to replace the warm, rising air.
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