Science 10

Chapter 14 Review Assignment

  1. Make a neat sketch of the Earth and label the following: (4 pts)

  1. equator
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  1. Arctic Circle
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  1. Polar zones
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  1. Tropic of Capricorn

  1. Antarctic Circle
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  1. Temperate zones
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  1. Tropic of Cancer
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  1. Tropical zone

  1. Why is the tropical zone defined as the region between 23.5ºN and 23.5ºS?(1pt)

The tilt of the earth is exactly 23.5º, so the area between the lines of the tropics always has the sun at its greatest intensity.

  1. Explain why a point on the equator is moving much faster than a point on the Arctic Circle.(2 pts)

A point on the equator rotates through a larger distance than a point closer to the poles, in the same 24 h time, so it must have a faster surface speed.

  1. Explain how Coriolis Effect can cause the prevailing westerlies to blow from west to East, and at the same time, cause the Trade winds to blow from east to west. Include a diagram in your answer. (3 pts)

Since the Coriolis Effect causes all winds in the N. hemisphere to turn right, winds that are blowing toward the pole become westerlies (temperate zone), but winds blowing toward the equator become easterlies (polar and tropical zones).

  1. Describe the Jet stream and explain why it exists. (2 pts)

The jet stream is a very fast wind in the upper atmosphere that occurs where polar easterlies and temperate westerlies meet. Since the westerlies are warmer, they rise above the easterlies. In the upper atmosphere, the lack of friction plus the Coriolis effect cause them to increase in speed.

  1. Describe the pattern found in most gyres and how it impacts climates on the east and west sides of ocean basins. (3 pts)

Gyres tend to be warm on the western side. Warm, humid air masses form above them, creating warm, rainy climates on land nearby.

Gyres are cool on the eastern side, so the air above the water cannot become very humid. The land nearby often has desert or very dry climates.

  1. What factors are needed for a surface current to form? (2 pt)

A surface current forms when ocean waters are warmer and less saline, creating a separate layer near the surface. The current must have a prevailing wind (a steady wind in one direction) in order to start moving.

  1. What factors control the direction of ocean currents? (3 pts)

Once formed, the direction the current moves depends on the direction of the prevailing wind, the Coriolis effect, and the shape of continents that “steer” the current.

  1. Describe the “normal” pattern of winds and surface water temperatures in the Pacific Ocean and describe the changes that occur during an El Niño. (3 pts)

NORMAL: strong easterlies (Trade winds)

Warm water is “pushed” to the west (Tahiti/Australia)

Cold upwellings occur along the eastern part of the ocean (Peru)

El NiñoWEAK easterlies (Trade winds)

Warm water is spread evenly over the surface

Cold upwellings stop (fisheries collapse)

  1. Living in Nova Scotia (temperate zone), if you see thunderclouds to the East, should you expect that it will soon rain? Why or why not? (2 pts)

No. Since prevailing winds in Nova Scotia blow from West to East, a thunderstorm in the west has probably already passed by.