Download What Impacts Climate?

Name _____________________
Date __________________
Hour _____
What Impacts Climate?
Background
Climate is determined by the temperature and precipitation characteristics of a region over
time. The temperature characteristics of a region are influenced by natural factors such as
latitude, elevation and the presence of ocean currents. The precipitation characteristics of a
region are influenced by factors such as proximity to mountain ranges and prevailing winds.
These, too, are natural factors that influence precipitation.
The temperature and precipitation characteristics of a region remain relatively unchanged for
thousands of years. Changes in climate are very gradual. Various years throughout history may
be noted for being particularly hot, cold, wet or dry, but when many years are considered,
these wild fluctuations in climate combine with many relatively “normal” years to develop a
picture of the average climate characteristics of a region over time.
Problem
What effects do various factors have on the climate of a region?
Self-Assessment
The following statements relate to the Problem. Circle true (T) or false (F). Also circle how
confident you feel about your answer by circling H (high confidence), M (moderate), or L (low
confidence).
1.
The climate on the windward side of a mountain is warmer and dryer
than the climate on the leeward side.
2. Cities near large bodies of water have more temperature variation
throughout the year than cities in the center of a large landmass.
3. Cities at higher latitudes have lower temperatures than cities at
lower latitudes.
T or F
H, M, L
T or F
H, M, L
T or F
H, M, L
Part 1: Climographs
A quick way to get an idea
of the climate of a
particular place is to look at
a "climate-graph," or
"climograph." A climograph
is what scientists create to
show a particular location's
average temperature and
precipitation during the
year. Use the the diagram
of the U.S and the
climographs to answer the
following questions.
Muskegon●
Grand
●San Francisco
Junction●
●Denver
●Detroit
●St. Louis
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1.
Annual Climatology: San
Francisco, CA (SFO)
Annual Climatology: St.
Louis, MO (STL)
Elev: 8 ft Lat: 37o
37'N Long: 122o 24'W
Elev: 586 ft Lat: 38o
45'N Long: 90o 22'W
Does the temperature of San Francisco change much throughout the year? What is the
temperature range? __________________________________________________
2. Does the temperature of St. Louis change much throughout the year? What is the
temperature range? _________________________________________________
3. How does the latitude of St. Louis compare to the latitude of San Francisco?
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4. Examine the differences in precipitation throughout the year for each city. What do you
think could cause such a difference?
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5. St. Louis and San Francisco have the same average yearly temperature. However, St. Louis
has cold winters and hot summers, while San Francisco has a generally mild climate all year.
What do you think causes this?
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Annual Climatology:
Detroit, MI
Annual Climatology: Muskegon,
MI
Elev: 637 ft Lat: 42o
14'N Long: 83o 20'W
Elev: 625 ft Lat: 43o
10'N Long: 86o 14'W
6. Does the temperature of Detroit change much throughout the year? What is the
temperature range? _________________________________________________
7. By examining the climographs, you should see that Detroit has a lower average yearly
temperature than St. Louis. What do you think causes this?
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8. What do you think causes the difference in precipitation between Detroit and Muskegon in
August and September?
____________________________________________________________________
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Part 2: The Orographic Effect
When air is warmed it’s density decreases and it begins to rise. As it rises there is less
atmosphere above it, so there is less pressure on it and the air molecules can spread out. As
they spread out, they take their heat with them. Imagine a cubic meter rising with the air. As
the air expands, there will be fewer molecules in the cube, which means there will be less
HEAT in the cube. This will cause a drop in the temperature. The expansion of the air causes
the temperature to drop, though no heat is actually taken from the air. Temperature changes
that occur due to expansion or contraction and without gain or loss of heat are called adiabatic
temperature changes. Normally as air rises in the lower atmosphere the temperature drops at
a rate of 10ºC for each kilometer (1000 meters) it rises. This is known as the Dry Adiabatic
Lapse Rate.
When the air spreads out (as it rises) it opens up space which more water molecules can fill,
allowing more water molecules to evaporate into the air than would have at a lower altitude.
This lowers the dew point by a rate of about 2ºC for each kilometer of rise. This is known as
the dew point lapse rate. After air has reached its dew point it continues to cool as it rises
upward, but it does so at a slower rate known as the Wet Adiabatic Lapse Rate and is about
5°C per kilometer (1000 meters).
When air is cooled below the dew point and the relative humidity is 100%, condensation
exceeds evaporation and the amount of liquid water increases as dew or cloud/fog droplets
form and grow. As air rises, the temperature drops 10ºC for each kilometer, and the dew point
drops 2ºC per km. If this goes on long enough, the falling temperature will eventually catch up
to the falling dew point. When this happens, condensation will exceed evaporation and tiny
droplets of liquid water will form in the air. We call a mass of tiny water droplets in the air a
cloud (or fog if at ground level).
The diagram below shows an air parcel being forced over a mountain range. This causes
changes in temperature (T), relative humidity (RH) and the dew point temperature (Td) as a
result of pressure changes. Calculate what the temperatures at the various points using the
appropriate adiabatic lapse rates and fill in the corresponding blank lines.
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4000 m
_____ _100%_ _____
3000 m
_____ _100%_ _____
2000 m
_____ _100%_ _____
1000 m
_____ _75%_ _____
Sea Level
_25__ _50%_ _13
T (C°)
RH
Td(C°)
4000 m
______ _100%_ _____
3000 m
______ _100%_ _____
2000 m
______ _75%_ _____
1000 m
______ _ 50%_ _____
Sea Level
______ _40%_ _____
T (C°)
RH
Td(C°)
Circle the correct responses.
9. As air rises it (expands, contracts).
10. As air rises, temperature (increases, decreases).
11. The capacity of the air (increases, decreases) as the air gets cooler.
12. The air at sea level is (saturated, unsaturated).
13. Clouds will begin forming at (1000, 2000) meters.
14. The air will initially (warm, cool) as it rises over the windward side of the mountain at
the (wet, dry) adiabatic rate, which is (10, 5) C per 1000 meters.
15. Condensation (will, will not) take place at 1000 meters.
16. From the altitude where condensation begins to occur, to the summit of the mountain,
the rising air will continue to expand and will (warm, cool) at the (wet, dry) adiabatic
rate of about (10, 5) C per 1000 meters.
17. Assume the air begins to descend on the leeward side of the mountain, it will be
compressed and its temperature will (increase, decrease).
18. Assume the relative humidity of the air is below 100% during its entire descent to the
plateau. The air will be (saturated, unsaturated) and will warm at the (wet, dry)
adiabatic rate of about (10, 5) C per 1000 meters.
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19. As the air descends and warms on the leeward side of the mountain, its relative
humidity will (increase, decrease).
20. Explain why mountains might cause dry conditions on their leeward sides.
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Annual Climatology: Denver,
CO (DNR)
Annual Climatology: Grand
Junction, CO (GJT)
Elev:5286 ft Lat: 39o
46'N Long: 104o 52'W
Elev: 4858 ft Lat: 39o
08'N Long: 108o 32'W
21. Based on the climographs of Denver and Grand Junction, how can you tell which is on
the leeward side of the Rocky Mountains and which is on the windward side?
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22. By examining the climographs, you should see that Denver has a lower average
yearly temperature than St. Louis. Explain what you think causes this?
______________________________________________________________
______________________________________________________________
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Part 3:
1.
Use the Diagram of Imaginary Continent to answer the questions.
a. The diagram represents an imaginary continent on the Earth surrounded by
water.
b. The arrows indicate the direction of the prevailing winds.
c. Two large mountain ranges are also indicated.
d. Points A, B and E are located at sea level; points C and D are in the foothills of
the mountain; point F is high in the mountains.
Circle the correct answer and then explain your answer.
23. Which city probably has the same type of weather year round?
(A, B, C, D, E, F) Why? _______________________________________________
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24. What factor would cause location F to have a colder yearly climate than any other
location? (ocean, mountains, latitude, elevation, inland, wind direction) Why? _______
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25. What 3 factors would cause location E to have the greatest annual rainfall?
(ocean, mountains, latitude, elevation, inland, wind direction) Why?
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26. Which location would you expect to have the greater annual rainfall? (C or D) Why?
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27. Which location would you expect to have the greater range in temperature during the
year? (A or B) Why?
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28. Location A is in the center of a large desert. What 3 factors could account for its low
annual precipitation? (ocean, mountains, latitude, elevation, inland, wind direction)
Why? ____________________________________________________________
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29. What 3 factors could cause the climate in location D to be cooler than at location B?
(ocean, mountains, latitude, elevation, inland, wind direction) Why?
_________________________________________________________________
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30. Which city would you expect to have a climate similar to San Francisco?
(A, B, C, D, E, F) Why? _______________________________________________
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Conclusion
1.
The climate on the windward side of a mountain is warmer and dryer
than the climate on the leeward side.
T or F
If false, what is your claim?____________________________________________
_________________________________________________________________
Evidence: _________________________________________________________
_________________________________________________________________
Reasoning: ________________________________________________________
_________________________________________________________________
2. Cities near large bodies of water have more temperature variation
throughout the year than cities in the center of a large landmass.
T or F
If false, what is your claim?____________________________________________
_________________________________________________________________
Evidence: _________________________________________________________
_________________________________________________________________
Reasoning: ________________________________________________________
_________________________________________________________________
3. Cities at higher latitudes have lower temperatures than cities at
lower latitudes.
T or F
If false, what is your claim?____________________________________________
_________________________________________________________________
Evidence: _________________________________________________________
_________________________________________________________________
Reasoning: ________________________________________________________
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