Download Winds-shortened

Open Video Clip on Global Wind Patterns
And High Low Pressure
Weather Map for Tuesday, April 17th
WIND
Is air in motion
Is caused by the uneven heating of the earth’s surface by
the sun
Warm air which weighs less than cold air, rises. Cool air
moves in and replaces the rising warm air
High to
Low Video
Clip
COOL AIR
WARM AIR
High pressures are cool air; low pressures are warm air
Winds blow from a high pressure to a low pressure
Winds are named by the direction they blow from
DIFFERENT TYPES OF WIND
PATTERNS
1. JET STREAM: narrow
belts of strong winds found
in the lower stratosphere
Video Clip on
Global Winds…3 min
2. GLOBAL WIND PATTERNS:
These are winds that are
happening in the upper
atmosphere ALL THE TIME.
These patterns are made
because hot air (low
pressure) rises and cold air
(high pressure) sinks.
Tradewinds— 0-30 degrees latitude
•at the equator (0 degrees), air rises, and then sinks at
around 30 degrees north and south
Westerlies— 30-60 degrees latitude
Air sinks at 30 degrees north and south and rises again at 60
degrees north and south
Are responsible for moving weather across the U.S.
Polar Easterlies— 60-90 degrees latitude
Air rises at 60 degrees north and south, and then sinks at the
poles
Doldrums
are found at the equator and are
weak winds.
Horse Latitudes
Found at about the 30° latitude
over the oceans…weak winds
here
3. LOCAL BREEZES: occur because of the heating
differences of land and water
SEA BREEZES—a convection
current blows wind from the
cooler sea towards warmer
land during the day
Land warms up faster than
water during the day
Cool Air
Sea Breeze
Warm Air
Wind blows from a high to a
low (cold to warm)
LAND BREEZES occur at night, air moves toward the
water as the land cools more rapidly than the water.
Water keeps its heat longer than land at night
Winds are named by the direction they blow from
Warm Air
Land Breeze
Cool Air
AMAZING EARTH SCIENCE FACTS
Winds are caused by the uneven heating of the earth
1. _______
Coriolis effect causes deflections of the atmosphere
2. ______________
and oceans due to the rotation of the Earth
high
low pressure
3. Winds blow from ________
pressure to _______
high pressure because the molecules
4. Cold air is ________
are close together and weight more than hot air
5. Warm air is ______
low pressure because the molecules
are far apart, therefore weight less
westerlies
6. U.S. weather is dominated by prevailing ____________.
Weather moves west to east.
Sea breeze- daytime, land is hot (low pressure)
7. ______
ocean is cold (high pressure) winds blow high to low
Land breeze-occurs at night and is the exact
8. _______
opposite of the conditions above