Metr 201 (502) Quiz # 5 Name: Solution

November 3, 2000

1) Why do winds usually change direction and speed when moving over a large body of water?

The frictional force on the wind is much smaller over water than it is over land. So when the wind passes over the water it speeds up. Because the Coriolis force increases as wind speed increases, the now faster wind is deflected to the right.

2) Which wind will most likely produce clouds: a valley breeze or a mountain breeze? Why?

Valley breezes form when the sun heats the side of a mountain more than the valley below it. As the air adjacent to the mountainside heats up it becomes less dense and rises. As this rising air cools it may saturate leading to cloud formation. The key thing to remember is that the wind is named for its origin (valley), not its destination (mountain).