ANABATIC WIND

also called upslope wind local air current that blows up a hill or mountain slope facing the Sun. During the day, the Sun heats such a slope (and the air over it) faster than it does the adjacent lowland because the slope's surface is more nearly perpendicular to the Sun's rays. This warming decreases the density of the air, causing it to rise. More air rises from below to replace it, producing a wind. An anabatic wind may attain a velocity of 6 metres per second (about 13 miles per hour).