Air Density, Convection, and the Movement of Air Molecules
Do you wonder why the weather changes all the time? Would you like to fly an airplane someday? If you answered “yes” to either of these questions, you need to learn how air molecules move!
When we feel many air molecules moving in one direction, we say the wind is blowing. When a large amount of air moves downward, that is called a downdraft. When a large amount of air moves upward, it is called an updraft. An airplane pilot has to regularly adjust to both updrafts and downdrafts. Convection is the term describing the upward and downward movement of air (or liquids). The underlying cause of these movements is differences in density. Density is the amount of matter in a given amount of space. Dense air sinks, creating downdrafts, while less dense air rises, creating updrafts.
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