Name _______________________________________
MET 102
Using Climatic Data to Identify Factors Influencing Climate
Introduction:
Climate is a description of aggregate weather conditions for a region. It is the sum of all the statistical
weather information that helps to describe a place or region. Climate is the result of the physical interaction
between Earth’s atmosphere, bodies of water, regions covered by ice, and land surface.
In this activity seasonal patterns of temperature and precipitation will be examined and related to the
physical factors that influence them. Data is presented in diagrams called climographs. A line graph presents
monthly mean temperatures (in Celsius degrees) and monthly precipitation is shown using bar graphs (in
centimeters).
A.
Comparing Annual Temperature Range as a Function of Latitude
The climographs for three locations, each at a different latitude, are shown below.
1.
Which location has the greatest annual temperature range? _______________________
2.
Which location has the smallest annual temperature range. _______________________
3.
Which location would be considered tropical?
_______________________
4.
Which location would be considered mid-latitude?
_______________________
5.
Which location would be considered polar?
_______________________
6.
What is the relationship between increasing latitude and annual temperature range? Why?
7.
What appears to be the relationship between latitude and precipitation? Why?
M ET 102: Professor Vorwald
Climate Factors
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B.
Coastal vs. Continental Temperature Ranges
The mean monthly temperatures of four United States cities are shown in the data table below. New
York and Bismark have similar latitudes as do Phoenix and Los Angeles.
Graph the average monthly temperatures for the four cities on the grid that is provided below. Select a
vertical scale that will accommodate annual temperature ranges for all four cities. Use a different color for each
city and include a key.
AVERAGE MONTHLY TEMPERATURES (CO)
Jan
Feb
Mar
Apr
May
June
July
Aug
Sept
Oct
Nov
Dec
New York, NY
0
2
6
12
18
23
25
25
20
15
9
3
Bismarck, ND
-13
-9
-3
7
13
18
22
20
14
8
-2
-10
Los Angeles, CA
15
16
17
18
19
22
24
24
24
22
18
15
Phoenix, AZ
13
15
17
22
27
32
35
34
30
24
17
13
M ET 102: Professor Vorwald
Climate Factors
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1. Even if you didn’t know these were all cities within the United States, how could you determine from
the climographs that they were all in the Northern Hemisphere
2. Which city has the greatest annual temperature range?
__________________________
3. Explain the cause of the greater range you observed in Question 2.
4. How do the rates of heating and cooling differ for New York and Bismarck?
5. What is the annual temperature range for Los Angeles?
____________________
6. What is the annual temperature range for Phoenix?
____________________
7. Considering Los Angeles and Phoenix are at similar latitudes, what can be inferred about the intensity
and duration of insolation at both locations?
8. Explain the reason for the difference in temperature ranges for Los Angeles and Phoenix.
C Marine Climates vs. Continental Climates
Refer to the two climographs below to answer the following questions. Both locations, A and B are at similar
latitudes. One location is Yakutsk, Russia and the other is Reykjavik, Iceland.
1. Which location has the largest annual temperature range?
________
2. What is the temperature range for location A?
________
3. Which location has its dry season in the summer?
________
4. Which location would be considered a marine climate?
________
5. Which location is Reykjavik, Iceland?
________
M ET 102: Professor Vorwald
Climate Factors
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D. Prevailing Winds and Geographic Position
Of the three cities represented by the climographs below, San Francisco has a marine climate due to the
moderating effects of the Pacific Ocean. As would be expected, St. Louis being far from a large body of water,
has a much greater annual temperature range. However, Norfolk at about the same latitude as San Francisco
and St. Louis, has a temperature range more like the continental climate of St. Louis than the marine climate of
San Francisco.
Based on this information and the climographs, answer the following questions.
1. These three cities are in which belt of prevailing planetary winds? _________________________
2. What is the reason that Norfolk has a more continental temperature pattern than San Francisco?
3. What is the probable cause of the pronounced reduction in rainfall in San Francisco’s summer season?
E. The Effect of Mountains on Climate
The Cascade Range in the Northwestern United States is a north-south trending mountain barrier that
modifies the air flow from the predominant westerly winds that blow off the Pacific Ocean. This results in the
orographic effect creating different climate conditions on the windward and leeward sides of the mountains.
Based on this information and the climographs, answer the following questions.
1. Which city is on the windward side
of the Cascade Mountains?
2. What causes the rainshadow on the
leeward side of the mountains?
M ET 102: Professor Vorwald
Climate Factors
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The orographic effect significantly influences rainfall patterns on the Big Island of Hawaii. These patterns
can be seen by comparing a topographic map that shows locations of mountains to a rainfall pattern map.
1. The map below shows isolines called isohyets that connect points of equal rainfall. Trace over and
darken the following isohyets: 20 inches, 50 inches, 200 inches.
2. Shade in the intervals of rainfall according to the key provided below.
Hawiian Island maps from:
Explorations in Earth Science by Osmun, R, Vorwald, B, and S. Wegner, ©2004 United Publishing Co. .
Reprinted with permission of authors.
M ET 102: Professor Vorwald
Climate Factors
Page 5
3. Compare the rainfall patterns to the topography of the Big Island. Peaks of the volcanic mountains are
shown using triangle symbols. Transferring the rainfall pattern to a piece of tracing paper and then
placing it over the topographic map will facilitate this comparison. Answer the questions that follow.
a. Which coastline of Hawaii has the most annual rainfall?
b. Describe the most likely direction of the prevailing winds across the Big Island of Hawaii.
c. Where is there a rainshadow area on the Big Island of Hawaii?
M ET 102: Professor Vorwald
Climate Factors
Page 6
F. The Effect of Ocean Currents on Climate
1. London, England at a latitude of 51o North has a climate similar to Seattle, Washington (~ 47o North).
New York City which is 12o latitude south of London has a January mean temperature that is 4.5o C
lower. Considering it’s latitude, what is the cause of London’s yearly temperature pattern?
2. What is the effect of the Benguela Current on locations along the western cost of southern Africa?
3. What is the effect of the Brazilian Current on temperatures in Rio de Janeiro, Brazil?
4. What is the effect of the Peruvian Current on Arica, Chile?
5. What is the effect of the California Current on summer temperatures in southern California?
Climographs from:
M ET 102: Professor Vorwald
Carone, Greg. Exercises for Weather and Climate, Fourth Edition. Upper Saddle
River, New Jersey: Prentice Hall, 2001.
Climate Factors
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