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21 Cards in this Set
- Front
- Back
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Know Global Cell Diagram
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The continental United States is located
between 25° and 49° north latitude. What area of the Global circulation model does the United States fit into? |
Westerly wind belt and the Ferrel circulation cell.
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Why and how do the average surface
pressure systems shift from summer to winter. |
Because of the suns shift towards the tropic of cancer.
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List the semi permanent high and low
pressure systems that affect the weather patterns over the Northern Hemisphere. |
Bermuda high → located over the mid
Atlantic ocean Pacific high → located off the western U.S. coastline Icelandic low → located over southern Greenland and Iceland Aleutian low → located over the Aleutian Island chain of Alaska. |
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How do the semi permanent pressure
systems change in strength and location from winter to summer? |
Bermuda high → strongest in the summer
and shifts west towards the United States Pacific high → strongest in the summer and shifts north Icelandic low → much stronger in the winter and shifts to the west, some years it will be located over eastern Canada Aleutian low → much stronger in the winter and shifts south to the Gulf of Alaska. |
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What are the four weak shallow thermal pressure systems form over the Northern Hemisphere called and when and where are they formed?
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Canadian thermal high-Forms in winter over west central Canada.
Siberian thermal high- Forms in winter over Russia and is responsible for dry monsoon season. Southwestern US thermal low- Forms in summer around South west region of US, responsible for weak monsoon season. Iran thermal low- Forms in sumer over the Iranian peninsula creating wet monsoons. |
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Define “Jet Stream”.
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Region of relatively strong winds concentrated narrowly in the atmosphere. Around 33,000-49,000 ft
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Name the two dominant jet streams and
identify their approximate location and height above sea level. |
1) Subtropical Jet Stream → above subtropical high (43,000 ft)
2) Polar-Front Jet Stream →near polar front (33,000 ft) |
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Major role of “Jet Streams” in
relation to global circulation |
Transfers heat by directing colder air
equator ward and warmer air pole ward. |
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How does the polar front influence the
development of the polar-front jet stream? |
Separates the cold polar air to the north from the warm subtropical air to the south. Rapid change in temp. creates pressure gradient which intensifies wind speeds.
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Why is the polar-front jet stream stronger
and found further south in the winter than the summer? |
In winter, the winds blow stronger and winds move farther south versus the summer where the winds are weaker and located over northern regions. Seasonal variation.
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What is low jet level?
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When air near the ground cools and
becomes heavier than warmer air above. Winds blow across the top of the heavier air, with little friction to slow them down. |
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What is a “Jet Streak”?
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Smaller regions of the greatest wind speeds in the jet stream.
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relationship between the
circulation of air and the circulation of ocean currents. |
wind flow around the globe interacts and correlates with the surface of water due to the force of friction.
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What major role do ocean currents play in the
scheme of global circulation? |
Balance the worlds imbalance of heating. Equalize the latitudinal energy .
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Name the major ocean currents that flow off
of the east and west coasts of the United States. |
1. Gulf Stream → warm southerly current along
the east coast that flows from Florida to the Mid-Atlantic states 2. Labrador Current → cold northerly current along the New England states that flows from Canada to the Mid-Atlantic states 3. California Current → cold northerly current that flows down the entire west coast. |
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What is “upwelling” and what causes this to
occur along the western coastline of the United States? |
As surface water drifts away from the coast, cold,
nutrient-rich water from below rises to replace it. |
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Define “El Nino”.
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extensive warming of the ocean surface
temperatures. Occurs once every 2-7 years. |
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What winter weather patterns typically set up
across North America during an El Nino event? |
1. Warmer conditions from Western Canada to the Great
Lakes region. 2. Drier in the Ohio River Valley 3. Wetter and colder across the far southern regions of the United States and northern Mexico. |
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What is “La Nina”?
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Waters off of Peru and Ecuador in South America
become colder than normal. Not as pronounced. |
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What winter weather patterns typically set up
across North America during a La Nina event? |
1. Colder from western Canada to the Dakotas.
2. Wetter and colder over the Pacific Northwest 3. Drier across the far southern regions of the US from the desert SW to Florida 4. Warmer and wetter across the Ohio River Valley |
