Essential Questions
1) Describe how the
Sun affects airflow?
Atmosphere: Section 3, Air Movement
1) Forming Wind:
Uneven heating of the Earth’s surface by the Sun causes some areas to be
warmer than others. (Warmer air expands causing it to become less
2) How does the
dense so it will rise, while Colder air contracts causing it to become more
Earth’s shape affect the
dense so it will sink) This change in density causes differences in air
amount of sunlight it
pressure. Wind is the movement of air from an area of high pressure
receives?
(cold, more dense) to an area of lower pressure (hot, less dense).
2) Heated Air:
3) Describe the Coriolis
Due to the Earth’s curvature it receives different amounts of radiation.
Effect on wind
The Equator receives more radiation than areas to the north and south.
patterns.
The air around the equator is less dense so it will rise due to more dense
colder air forming convection currents. The colder dense air comes from
4) Describe the
the poles where it receives the least amount of radiation.
different wind
3) The Coriolis Effect:
patterns. (names,
Due to the rotation of the Earth, wind does not blow in a straight line.
direction of flow,
Wind curves from the west to east and from the poles to the equator.
reason for names,
The Coriolis Effect is the effect that the Earth’s rotation and the uneven
latitudes)
heating by the Sun’s radiation have on global wind patterns.
4) Wind Patterns:
5) What are Jet
Prevailing Westerlies: Start new 30O North and South latitude and
Streams and how do
flows toward the 60O N and S latitudes, air moves from West to East.
humans use them
These are the wind patterns that affect weather the most in the U.S.A.
throughout travel?
Doldrums: Wind pattern along the equator, due to direct sunlight the
wind is very light and daily rain can be expected because of the rising
6) Why does a sea
hot/moist air.
breeze blow from the
Trade Winds: Starts at the Equator and goes toward the 30O N and S
sea toward land?
latitude, air moves from East to West. Sailors used these winds to travel
the most, hence the name Trade Winds.
7) Why does a land
5) Jet Streams:
breeze blow from land
Narrow belts of strong winds. Moves faster in the winter due to the
toward the sea?
differences between cold polar air and warm tropic air. High altitude
pilots traveling west to east take advantage of these jet streams to save
time and fuel.
6) Sea and Land Breezes: these daily winds occur because land heats up
and cools off faster than water, creating a difference in air pressure
resulting in local wind patterns.
Sea Breezes are created during the day because solar radiation warms
the land more than the water. So the more dense sea air flows toward
the less dense land air causing convection current.
Land Breezes are created at night because the air of the water is still
being heated causing it to be less dense, while the air over land has
cooled off greatly resulting in a denser air mass. This cause air to flow
from land toward the sea.