8.10B
1. Look at the weather map.
In which area are you most likely to find sunny skies? (Hint: Step 1. Recall what type of air pressure indicates sunny skies. Step 2. Find these areas on the map and identify their locations.)
Anywhere there is a high pressure.
8.10A
2. Refer to the diagram of winds and currents below to answer the question.
What is the direct source for these winds and currents?
Coriolis effect makes the winds curve to the right from their north-to-south or south-to-north direction in the Northern Hemisphere.
3. Differences in air pressure drive the global wind systems on Earth. What term describes polar winds that blow from east to west? easterlies are polar winds that blow from east to west.

4. The global movement of air occurs in convection cells. In general, how does air move? air generally moves from areas of higher pressure to areas of lower pressure.
5. The Coriolis effect is the curving of the path of a moving object in Earth’s atmosphere that is caused by
Earth’s rotation. How does the Coriolis effect affect winds globally?
Coriolis effect affects the direction of the wind
6. The following figure shows a valley between two mountains. The arrows indicate the direction of air movement.
Which type of breeze is illustrated in the figure? a mountain breeze forms when cool air moves down a mountain slope toward a valley.

7. Different factors influence the movement and direction of ocean currents. The following map shows
Earth’s major surface currents in the ocean.
What factor causes surface currents north and south of the equator to move in different directions?
Coriolis effect causes water to move to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
8. Dom makes a table to compare the percentage of various gases in the atmosphere to the percentage of gases dissolved in the ocean. His table is shown below.
Gas Percentage in atmosphere
Percentage in ocean water nitrogen oxygen argon
78.08
20.95
0.93
62.6
34.3
1.6 carbon dioxide 0.033 1.4
Which of the gases listed in Dom’s table is less common in ocean water than it is in the atmosphere?
(Hint: Step 1. Compare the percentage in the atmosphere to the percentage in ocean water for each gas. Step 2. Identify the gas for which the percentage in ocean water is less than the percentage in the atmosphere.) percentage of nitrogen in ocean water is 62.6%, which is less than the percentage of nitrogen in the atmosphere, 78.08%.

9. The following map shows trade winds and westerlies in the Northern Hemisphere.
What do the unlabeled arrows represent? arrows show surface currents. A surface current is the horizontal movement of ocean water near the ocean surface that is caused by wind.
8.10C
10. Explain why the coastline of the western United States is cooler than the coastline of the eastern United
States? (Hint: Step 1. Recall what factors can affect weather patterns near the oceans. Step 2. Determine exactly which of these factors causes the two coastlines to have different temperatures.) the west coast experiences a cold surface current, which brings cold water from higher latitudes. The east coast experiences a warm surface current, which brings warm water from lower latitudes
11. A teacher is explaining global winds and draws the following table on the board.
Wind
Trade winds
Westerlies
Location Notes
Equator to 30°, both hemispheres curve to the west
30° to 60°, both hemispheres curve to the east
Polar easterlies curve to the west
What information should the teacher write in the missing section of the table? because the polar easterlies occur closest to the poles, from 60° to 90° latitude in both hemispheres

Gridded Response
Write your answer in the boxes, then bubble in the corresponding number in the grid below.
12. Different ions are found in ocean water. Marta’s teacher gives her the following table, which lists the concentrations six most common ions found in ocean water.
Ion chloride sodium magnesium
Concentration (mg/kg)
19,350
10,760
1,290 sulfur 2,710 calcium 411 potassium 399
How many times more concentrated than sodium is chloride?
Round your answer to the nearest tenth.
Divide the concentration of chloride in ocean water by the concentration of sodium in ocean water.
19,350  10,760  1.798
1.798 rounded to the nearest tenth is 1.8.
1.8
Critical Thinking
Answer the following questions in the space provided.
13. The picture below shows a situation that causes local winds.
Draw an arrow on the picture to show which way the wind will blow.
Describe why the wind blows in that direction and name this type of local wind. correctly explains that the movement of wind is from higher air pressure to lower air pressure and correctly names sea breeze

8.10C
14. Explain how La Niña differs from El Niño.
La Niña: characterized by cooler-than-normal ocean temperatures in the equatorial Pacific Ocean;
El Niño characterized by warmer-than-normal ocean temperatures in the equatorial Pacific Ocean
Describe at least two ways how an El Niño event can change global weather.
(2 of the following):
Water temperatures over the equatorial Pacific Ocean are warmer than average, higher-than-average pressure builds over the western Pacific Ocean, and lowerthan-average pressure builds up over the eastern Pacific Ocean.
Winds that normally blow from east to west shift to a more west-to-east direction. Warmer-than-average ocean-water temperatures spread eastward from the central Pacific Ocean. When this occurs, the jet stream patterns change.
The Polar Jet Stream strengthens and moves south, which causes increased precipitation and potential flooding in California, along the Gulf Coast, and in the
Southeast. The Subtropical Jet Stream strengthens, which increases tropical storm activity across the eastern Pacific Ocean.
In the Southern Hemisphere, the Subtropical Jet Stream moves northward toward the equator, which causes increased precipitation in countries such as Peru and
Bolivia.
At the same time, droughts can occur in the western Pacific in Southeast Asia and Australia. El Niño conditions decrease tropical cyclone (hurricane) activity in the North Atlantic Ocean.
8.10 A
15. Understanding global weather means understanding what happens when air pressure and density change.
Use your knowledge of solar energy, air pressure, and density to explain what happens to air at the equator and at the poles. Then, describe the type of weather that is likely to result from the following two scenarios.

1. Air pressure at the poles decreases.
Scenario 1: Strength of the westerlies increases, bringing more wind toward the poles and bringing warm air to middle latitudes.
2. Air pressure at the poles increases.
Scenario 2: The westerlies weaken, and the winds blow from the direction of the poles toward the equator. This brings cold air into the middle latitudes.