Student Exploration Sheet: Growing Plants s17

Name: ______Date: ______

Student Exploration: Coastal Winds and Clouds Click Play ( ), and watch the Gizmo for 24 simulated hours, focusing on the sailboat.

1. Click Pause ( ) when the sailboat starts moving towards the shore. This represents the

start of the sea breeze. What time is it? ______

2. Click Play, and then click Pause when the sailboat starts moving out to sea again. This

represents the start of the land breeze. What time is it now? ______

3. Click Play, and now observe the clouds for a day. What do you notice? ______

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______Activity A: Get the Gizmo ready: Temperature and  Click Reset ( ). wind  Turn on the Weather probe. Question: How is wind speed and direction related to air temperature?

1. Think about it: Imagine a pocket of air over the land (“land air”), and another pocket of air over the ocean (“ocean air”).

A. Which air pocket would you expect to heat up more during the day? ______

Why? ______

B. Which air pocket would you expect to cool down more at night? ______

Why? ______

2. Gather data: Check that the time is 6:00 A.M. Drag the Weather probe so that it is on the ocean’s surface (Alt. 0 ft) on the left side of the Gizmo, and record the air temperature. Then, repeat with the probe on the land on the right side of the Gizmo.

Finally, move the probe to the land-sea boundary and record the type of breeze (sea or land breeze) and wind speed. Record data for each time listed in the table below.

Time Ocean air Land air Sea breeze or Wind speed temperature (°F) temperature (°F) land breeze? (mph)

6:00 A.M.

9:00 A.M.

12:00 P.M.

3:00 P.M.

6:00 P.M.

9:00 P.M.

12:00 A.M.

3:00 A.M.

3. Calculate: For both the ocean air temperature column and land air temperature column, find the temperature range by subtracting the lowest temperature from the highest.

A. How much does the temperature over the ocean change in one day? ______

B. How much does the temperature over the land change in one day? ______

4. Analyze: Compare the air temperatures to the breezes.

A. At 6:00 A.M., where was the warmest air? ______

B. At 6:00 A.M., in which direction did the breeze blow? ______

C. At 3:00 P.M., where was the warmest air? ______

D. At 3:00 P.M., in which direction did the breeze blow? ______

5. Summarize: What is always true when there is a land breeze? ______

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What is always true when there is a sea breeze? ______

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6. Draw conclusions: In general, the land changes temperature much more rapidly than the ocean. How does this fact explain the existence of land breezes and sea breezes?

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______7. Extend your thinking: With the probe placed on the land-sea boundary, monitor the wind speed. Click Pause when the strength of the sea breeze is at a maximum. A. At what time of day is the sea breeze strongest? ______

B. Use the Weather probe to measure the land-air and ocean-air temperatures. What

are these temperatures at this time? ______

C. Click Play, and then click Pause when the strength of the land breeze is at a

maximum. What is the time? ______

D. What are the land- and ocean-air temperatures now? ______

E. The wind changes direction at approximately 9:10 A.M. and 12:10 A.M. What is true

about each of these times? ______

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Question: Why do land breezes and sea breezes occur?

Activity B: Get the Gizmo ready: Convection  Click Reset. currents  Turn on the Drifting balloon. 1. Observe: Click Play, and observe the balloon for a period of 48 hours. Pause the simulation whenever the balloon changes direction. Describe what you see in the space below.

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2. Analyze: During what time period does the balloon drift in a clockwise direction? ______

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During what time period does the balloon drift in a counterclockwise direction? ______

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3. Gather data: The diagram at right shows the scene at 6:00 A.M. Use the Weather probe to find and label the temperature at each of the numbered locations. Next, find the wind direction between the points on the diagram. Draw arrows to represent the movement of air. Which points represent the lowest and highest temperatures on the diagram?

Lowest: ______Highest: ______

4. Analyze: In which direction is the hottest air in the diagram moving? ______

In which direction is the coldest air in the diagram moving? ______

This pattern—in which low-density, hot air rises while high-density, cold air sinks—is an example of convection. The resulting circular flow of air is called a convection current.

5. Gather data: Click Play, and then click Pause at 3:00 P.M. Use the Weather probe to find and label the temperature at each of the numbered locations.

Find the wind direction between the points as you did before. Draw arrows to represent the movement of air.

Which points represent the lowest and highest temperatures on the diagram?

Lowest: ______Highest: ______

6. Analyze: In which direction is the hottest air in the diagram moving? ______

In which direction is the coldest air in the diagram moving? ______

7. Explain: What causes the counterclockwise flow of air in the afternoon? ______

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8. Observe: Place the Weather probe at the land-sea boundary, and click Pause when the sea breeze is strongest.

A. What do you notice in the sky at this time? ______

B. Click Play, and then pause the simulation when the land breeze is strongest. What

do you notice in the sky now? ______9. Explain: Clouds often form when a large mass of warm, moist air rises quickly and cools, resulting in condensation of the water vapor.

Based on this statement, why do clouds tend to form around 3:00 P.M. and 6:00 A.M.?

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Take Quiz Relative Humidity

What is the difference between humidity and relative humidity?

What would happen to the relative humidity of an air mass if the amount of water vapor in the air stayed the same, but the temperature increased? Decreased?

Suppose a psychrometer’s dry bulb and wet bulb thermometers were the same temperature. What can you assume?

How does humidity relate to the temperature difference between the wet and dry bulb thermometers? Why is this true? Take Quiz

Weather Maps Why are high-pressure systems associated with dry and sunny weather?

Why are low-pressure systems associated with moist air?

Why does air tend to circulate in a clockwise direction around a high-pressure system, and in a counterclockwise direction around a low-pressure system?

What causes clouds to form? Based on this, why do clouds often form along fronts? Take Quiz Student Exploration: Hurricane Motion

You can use data collected from weather stations to study the characteristics of hurricanes. The Hurricane Motion Gizmo™ has three simulated weather stations. Turn on Show weather station data. Make sure Wind, Cloud cover, and Pressure are all checked.

The tails on each station symbol point in the direction the wind is coming from. The flags on the tail indicate wind speed, measured in knots. (One knot is equal to 1.151 mph.) A short line extending from the tail indicates 5 knots of wind. A longer line indicates 10 knots. A triangular flag indicates 50 knots. Add all the flags together to get the wind speed.

The number in the station’s upper right is the air pressure, which is measured in millibars (mb).

The circle symbol indicates the percentage of cloud cover, as shown in the table at right.

Use the information above to complete this table for station A on the Gizmo.

Wind speed (knots) Wind from Cloud cover Pressure (mb)

Introduction: Hurricanes form when an area of low pressure forms over warm water. Winds blow toward the low pressure, but are deflected by Earth’s rotation. The Coriolis effect causes winds to curve to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This results in a counterclockwise rotation for Northern Hemisphere hurricanes and a clockwise rotation for Southern Hemisphere hurricanes.

Question: What are some characteristics of hurricanes?

2. Activity A: Get the Gizmo ready: O Hurricane  Make sure Practice, Show hurricane, and Show bs characteristics weather station data are selected. er ve : In which hemisphere is the hurricane shown on the Gizmo? ______

How do you know? ______

3. Describe patterns: Under Show hurricane, make sure Radar is selected. Radar is used to determine where precipitation, such as rain, is falling. Blue indicates light rainfall. Heavier rain is shown with yellow and then orange. Red indicates the heaviest rainfall.

A. Where within the hurricane is the lightest rainfall? ______

B. Where within the hurricane is the heaviest rainfall? ______

C. Describe any patterns you see in the distribution of a hurricane’s rain. ______

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4. Observe: Under Show hurricane, select Satellite. Satellite images are taken from cameras built into satellites orbiting Earth. These images are used to study cloud coverage over large areas, including the clouds associated with a hurricane. A. Which is larger, the area of rainfall or the area of cloud cover? ______

B. Where is the cloud cover most dense? ______

C. Where is the cloud cover least dense? ______

5. Identify: The center of rotation of a hurricane is called the eye. The eye of a hurricane is a core of warm, relatively calm air with low pressure and light winds. Label the eye on the hurricane at right.

Category Wind speed (mph) 6. Classify: Hurricanes are categorized based on 1 74-95 mph their wind speeds. The chart at right shows the five categories used to classify hurricanes. 2 96-110 mph 3 111-130 mph Move the hurricane so that the center of the 4 131-155 mph storm is directly over one of the weather stations. 5 greater than 155 mph A. Remember one knot is equal to 1.151 miles per hour. What is the hurricane’s highest wind

speed in miles per hour? ______

B. What category is this hurricane? ______

7. Observe: Move the hurricane towards another weather station. As you do this, observe the cloud cover, wind speed, and air pressure at the station.

A. How does the cloud cover change? ______

B. How does the wind speed change? ______

C. How does the air pressure change? ______

8. Collect data: Move a hurricane north, east, south, and west of a weather station. In the table below, record the wind direction in each case.

Hurricane position in relation to weather station Wind direction at weather station North East South West 9. Analyze: How can you tell the location of the hurricane relative to a weather station based on this

information? ______

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______Question: How can you predict the location and path of a hurricane?

1. Observe: Click Play ( ), and wait until you see a hurricane approaching one of the weather stations. Click Pause. What changes indicate a hurricane is approaching?

Cloud cover: ______Air pressure: ______

Wind speed: ______

2. Observe: Click Play, and wait for the hurricane to go over the land. What happens in the hours after

Activity B: Get the Gizmo ready: Predict hurricanes  Select Experiment and click Pause ( ). landfall? ______

3. Collect data: Click Reset ( ). Turn off Show hurricane. Click Play. When the simulation reads Day 1, 3:00 PM, click Pause and record the data from each weather station.

Station Wind speed (knots) Wind from Cloud cover Pressure (mb) A B C

4. Interpret: Using the readings above, do you think a hurricane is nearby? Explain.

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5. Run Gizmo: Allow the Gizmo to run until the weather station data indicates a hurricane is nearby and will soon make landfall. Click Pause.

A. What weather station data indicated a hurricane would soon make landfall? ______

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B. Turn on Show hurricane. Was your prediction correct? Explain. ______

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6. Gather data: Turn off Show hurricane, and click Reset. Click Play. At 12:00 P.M. of day 1, click Pause. Drag a pointer to the predicted position of the eye of the hurricane, and draw an arrow in the diagram below. Label this arrow “1.”

Turn on Show hurricane, and mark a circle where the actual eye is located. Label this circle “1.” Turn off Show hurricane, and then repeat this procedure every 12 hours to mark the predicted and actual path of the hurricane.

7. Make connections: As warm, moist air rises, water vapor in the air condenses and releases a great deal of heat energy. This energy powers a hurricane. How does this information explain what happens to hurricanes after they make landfall?

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______Take Quiz