Download 11.8 NOTES What causes local winds?

11.8 NOTES
What causes local winds?
Objective: Describe patterns of local winds
Winds are produced by temperature differences caused by the unequal heating of
Earth’s surface. Local winds are small-scale winds produced by local changes in
air pressure.
A breeze coming from the sea toward land is called a sea breeze. A breeze going
from the land to the sea is a land breeze. Land is heated faster than water; as a
result, air over land is warmer and lighter than air over water. Cooler air over the
ocean moves toward the land, pushing the warm air up.
At night, the air over the land cools off faster than air over the ocean. The cooler
air from the land moves toward the warmer air over the water, causing the air
over the water to rise.
Mountains also have local winds. During the day, the air over the mountain slope
is warmer than the air in the valley. The cooler high pressure air in the valley
moves up the mountain side toward the warmer air. This is called a valley breeze.
At night, the cooler, heavier mountain air moves down the valley. This is a
mountain breeze.
Parts of some continents
have winds that change
direction with the seasons.
These winds are called
monsoons. Summer
monsoons move from the
ocean to the land. These
winds bring moist air and
heavy rains. Winter
monsoons move from the
land to the ocean. These
winds bring dry air with
little rain.