Eeee-rump! Eeee-rump! The sound of a foghorn echoes in the night. A thick, grey fog creeps in from the ocean and settles over the waterfront. You can hardly see your hand in front of your face. It seems as if you are in the middle of a cloud.
As a matter of fact, that’s just what fog is. It’s a cloud of tiny water drops that touches the earth, instead of floating high in the sky.
Like every other kind of cloud, fog forms when warm, moist air meets cool air. Fog often forms when warm, moist air passes over the cold water or an ocean, lake, or river. The warm air quickly cools. Then the water vapour in it becomes millions of tiny drops – a cloud that rolls in from the water and spreads out over the land.
Fog forms over the land in much the same way when ground that has been warm all day begins to cool off. As the warm air above the ground cools, the water vapour in the air turns into tiny drops of water. A fog hugs the ground.
Picture Credit : Google