Grossmont CollegeIntroduction to Physical Geography

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Name: _________________________________ Instructor: Judd CurranWorld Patterns of Air Temperature

1. If insolation receipt were the only variable controlling the distribution of temperature, then how would the isotherms on a temperature map be oriented? Explain.

2. Refer to figure 5.21, but assume no continents are present (i.e., assume all ocean).a. Describe the temperature distribution that would result. Explain.

b. How will this distribution vary between July and January? Explain.

3. Refer again to figure 5.21, but assume continents are present as is illustrated.a. Describe the effect of continentatlity during summer. How does this affect the summertime distribution

of isotherms?

b. Describe the effect of continentality during winter. How does this affect the wintertime distribution of isotherms?

50°F

50°F

-20°N

-70°NO

CEAN

Isotherm over water onlyIsotherm over land

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4. On the map below, the 50°F isotherm line is drawn in two different positions. One of the positions represents the location of the 50°F isotherm in summer while the other position represents the location of the 50°F isotherm in winter.

a. Appropriately label the two dashed 50°F isotherms as either “summer” or “winter”.b. Draw in a hypothetical continent. (assume that the surface of this continent is made of a homogenous

material and at a constant elevation.)c. Using a solid line to represent the summertime 50°F isotherm, show the effect of continentality on the

summertime temperature distribution.d. Using a solid line to represent the wintertime 50°F isotherm, show the effect of continentality on the

wintertime temperature distribution.

5. On figure 5.20, why don’t the isotherms in January over South America reverse their orientation latitudinally in July, even though this reversal is predicted to occur in accordance with the correct answer to question 4 c-d?

6. Compare figure 5.20 to figure 7.31.a. On the July isotherm map, why do the isotherms that are located immediately off the Washington,

Oregon, and California coast bend south so abruptly?

b. What is the temperature of the isotherm located at 40°N off of the west coast of North America in July?

c. Looking in the same general location on the January isotherm map, in what direction (poleward or equatorward) is the same isotherm (the one you identified at 40°N in question 6 b) reside compared to July?

d. Based on the correct answers to b and c, what can you conclude about the direction that all isotherms shift in summer vs. winter?

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Fig. 5.20

January

season season

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Fig. 5.20

July

season season

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Figure 7.31