What makes wind blow?
The wind moves over the land. It sways the tops of tall grass in meadows
and sets leaves a-rustle in the woods. It scatters the smoke from
chimneys. It lifts up limp flags and makes them flap. It touches your
cheek with cool, quick fingers and impishly ruffles your hair. Wind is
moving air. And it is the sun that makes air move.
Sunlight falling upon the earth warms the ground in many places. The
heat from the ground then warms the nearby air. As the air grows
warmer, it starts to rise.
The earth spins around like a big top. As it spins, each part of the
earth, in turn, comes into the sunlight. The sun’s light warms the
earth. The heat makes the molecules of gas in the air move faster and
spread apart. This warm air rises up, in a kind of big, invisible cloud.
As the warm air rises, cooler air from other places flows in to replace
the warm air. This moving, cooler air is the wind. When you feel the
wind blow, you are feeling the movement of the cooler air pushing in to
take the place of the warm air.
As the warm air rises, cooler air from a cooler spot rushes in to take
its place. The movement of this cooler air is the wind. Wind is just
moving air.
