Investigation 1 - Ch-ch-ch-changes

Class Time Required	5-6 class periods
Materials Needed	Science notebooks Arctic sea ice data Scatterplot example Sea ice flip book video “Alaskan Native Thoughts on Climate Change” Sea ice animation Shrinking Ice Headlines PowerPoint Internet access Water Plastic cups Ice cubes Conical flasks Corks Glass tubes Thermometer Clamp-on lamps Floodlights Dye or food coloring Graph paper
Teacher Preparation	30 minutes to read through investigation and background and watch video. 30 minutes to gather materials and prepare handouts.
Prior Student Knowledge	Experience in graphing data
Vocabulary	albedo, arctic, fluctuate, scatterplot, thermal expansion
Science GLEs Addressed	6th Grade: SA1.1, SA1.2, SE2.2 7th Grade: SA1.1, SA1.2, SE2.2, SG3.1 8th Grade: SA1.1, SA1.2, SA2.1, SD2.1, SE 2.2, SE3.1, SG3.1

This investigation has been selected as an NSF-funded Climate Literacy and Energy Awareness Network (CLEAN) educational resource.

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Overview: This 5-6 day investigation challenges students to think about how sea ice is changing and the effects of a warming climate on sea level in Alaska. Students begin by viewing a presentation showing a Native Alaskan talking about the importance of ice to his life and his culture. They then view a series of photos and headlines about shrinking sea ice. In Activity 1A: Arctic Sea Ice Data, students graph data on sea ice extent over time. In Activity 1B: Melting Sea Ice and Sea Level, students participate in a lab activity that simulates the melting of sea ice, and create a flip book of images of the change in sea ice extent over time. Activity 1C: Temperature and Sea Level Rise demonstrates the thermal expansion of seawater as one process that could contribute to sea level rise.

Focus Questions:

How is sea ice changing over time?
How do scientists determine and communicate the patterns of change in the extent of arctic sea ice?
What effect will a warming climate and melting sea ice have on sea level?

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Engagement: (45 minutes)

Lead students in a 3-2-1 activity:
Ask students to think about what comes to mind when they hear the word “arctic.”
Allow students to free write for five minutes, capturing the thoughts that come to mind.
Then ask them to review their writing, and choose three main ideas from their writing. Students then pair up and share their three ideas with their partner. Between them, they now have six ideas and they must come up with two words that best describe the “arctic,” by consolidating their own and their partner’s ideas. Allow five minutes or less for this. Each pair then joins with another pair (there are now four words) and this foursome must come up with one word that best represents their idea of the arctic. Allow five minutes or less for this. Ask each group to share their word and why they chose that word with the class. Post all words on the board or chart paper and place it in a visible location in the classroom.

Show the video “Alaskan Native Thoughts on Climate Change”

Ask students to choose one word to describe the arctic, based on the video.
The intent of this activity is that they will choose the word “ice.”
Allow students to comment on the short video.

Show the Shrinking Ice Headlines PowerPoint that highlights past and current news about climate change and the changes in arctic sea ice. As students watch, they should look for impacts of ice melting. After viewing the video and PowerPoint, ask students to respond to the following question in their science notebooks:
“What do we know about sea ice and how it is changing?"

After students have had time to write, ask them to share their responses.

Begin a “Ladder of Learning” about sea ice: Record student responses at the bottom of a piece of chart paper to create the first “rung” of the ladder. Ask students to create this “Ladder of Learning” in their science notebooks and create the first rung by writing the information from the chart.

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Activity 1A: Arctic Sea Ice Data

Focus Questions:
How is arctic sea ice changing over time?
How do scientists determine and communicate the patterns of change in the extent of arctic sea ice?

Exploration: (45 minutes)

Distribute the arctic sea ice data handout to students. This data shows sea ice extent, but does not provide information about ice thickness.

Discuss the following questions with them:

Where do you think this data comes from? (Satellites. This helps explain whay data does not exist before 1979, since reliable data did not exist before then).

What are your first impressions when looking at this page?

If you were a scientist and given the task of sharing the news of this data with the world, how would you present it?

What would you expect to see if you picked one year and tracked the sea ice in the arctic?

Have students make a prediction in their science notebooks, then graph one year either by hand or using Excel. Students can choose a line graph, bar chart, or possibly a pictogram. After their graphs are complete, ask them to respond to the following question in their science notebooks:

According to your graph, what happens to the sea ice over one year?

Allow time for students to share their answers.

Present this question to the class:

If the ice is fluctuating yearly, how would we go about trying to communicate what our data shows about sea ice over many years? Consider all of the students’ ideas, and suggest a scatterplot if they don’t come up with that idea. Show the scatterplot example to students, and depending on student level, review how to make a scatterplot using one month of the year.

Individually or in pairs, students choose a month of the year to track sea ice extent. Students can create a scatterplot graph either by hand or by using Excel.

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Explanation: (10 minutes)

Have students describe the overall trend of the data in their science notebooks, and make a trend line (line of best fit) for their graphs.

Ask students to respond to the following questions in their science notebooks:
What is going on with respect to sea ice extent in the years from 1979 to present, as shown by the data?
Why do scientists use graphs instead of data tables to present large amounts of data?

Have students share their scatterplots with the class and discuss their answers to the questions with the whole group.

Show students the sea ice animation. Note that the years of the animation correspond very closely to the years they graphed. Ask students what they noticed. Was the ice ever similar to September 2007 during the animation? Why do they think the sea ice extent in 2007 is less than any of the previous years in the animation?

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Extension

You may show or have students watch the video "George Divoky: The BirdWatcher Who Saw the Future” which demonstrates a change in a population of black guillemots near Barrow, Alaska. The guillemots are ice-dependent arctic nesting seabirds. A 30-year study has documented changes in their habitat related to a retreating ice pack, and changes in their success in reproduction related to the distance they have to fly to find food, as well as the movement northward of horned puffins, a subarctic species. This video is a good introduction to the concept that physical changes in climate and ice and have effects on specific animals and their ecological relationships.

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Activity 1B: Melting Sea Ice and Sea Level

Focus Question:
If arctic sea ice melts, will the sea level rise?

If time, space, and materials are not available, this activity can be a demonstration by the teacher.

Exploration (45 minutes):

Arrange students in pairs. Each pair of students needs the following materials:

• Water
• 1 clear plastic 6-8 oz. cup
• Permanent felt-tip marker or tape
• Ice cube

Instructions:
1. Pour warm water into the cup, so that the cup is about half full.
2. Add an ice cube to the cup and carefully mark the level of the water with a permanent marker or a piece of tape.
Ask students to predict what will happen to the water level in their cup as the ice cube (iceberg) melts, and to record this prediction in their science notebooks.
3. Let ice melt in the cup. Report changes in sea level in their cups.

While students are waiting for their ice to melt, they can cut and assemble the sea ice flip book.

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Explanation: (20 minutes)

Ask students if their predictions were correct. Ask for explanations for why the water level in the cup did not change. Ask students to reflect on the following questions in their science notebook: What does this experiment suggest might occur to the sea level if arctic sea ice continues to melt?

Ice is less dense than water. An ice cube floating in a glass of water displaces the same volume of water that it contains. So, if sea ice were to melt, the sea level would stay the same.

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Extension

If you would like to further explore the concept of density, you can change this activity slightly. Use salty water in the cup, and melt a blue-colored ice cube in the water. The cold blue water from the ice cube will melt and form a distinct layer on top of the warmer, clear salt water, showing that even though it is much colder, it is less dense than the salt water.

Another option is to use warm fresh water in the cup, instead of salt water. The blue water from the ice cube will be more dense than the warmer water, so the blue water will sink to the bottom. It will gain heat energy as it sinks through the warmer water column, so as it moves along the bottom it will begin to rise.

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Activity 1C: Temperature and Sea Level Rise

Focus Question:
If arctic seawater becomes warmer, will sea level rise?

Exploration: (30 minutes)

1. Ask students to write a prediction in their science notebooks about what happens to a volume of water when it is heated, compared to its volume at room temperature. Will it become larger, become smaller, or stay the same?

2. Completely fill a conical flask with very cold water. (For increased visibility, add food coloring to the water.)

3. Place the cork in the stopper.

4. Slide the thermometer and glass tube into the holes in the cork. The water level should rise a short way into the tube.

5. Record both the temperature of the water and the water level in the glass tube.

6. Place the flask over the lamp.

Have the students draw the x and y axes of a graph on graph paper. Have them label the x-axis “time” and mark divisions for two-minute increments. Label the y-axis “height” which will be the measurements of the height of the water in the flask.
Turn on the lamp and have the students record the measurements on their graph every two minutes.

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Explanation (20 minutes):

Discuss why the level of water in the flask changed. Ask students to reflect on the following questions in their science notebook: What does this experiment suggest might occur if the oceans warm? Where would you expect the increase in sea level to be the highest? Would you expect this expansion from the application of heat (also called thermal expansion) to be enough to cause coastal flooding?

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Extension: (30 minutes):

As sea ice decreases in extent and the area of open water increases, the rate of melting will accelerate due to another physical process. The “albedo” indicates how well a surface reflects or absorbs solar energy. Sea ice has a much higher albedo compared to other earth surfaces, such as the surrounding ocean. This means that the ocean reflects only 6% of the incoming solar radiation and absorbs the rest, while sea ice reflects 50 to 70% of the incoming energy. The sea ice absorbs less solar energy and keeps the surface cooler. Snow has an even higher albedo than sea ice; therefore thick sea ice covered with snow reflects as much as 90% of the incoming solar radiation. This serves to insulate the sea ice, maintaining cold temperatures and delaying ice melt in the summer. After the snow does begin to melt, the surface albedo drops. As melt ponds grow and deepen, the surface albedo will drop even further. This concept can be illustrated with It’s a Cool Color, an activity developed by the Smithsonian Institution.

This activity also has excellent teacher reference images and graphs of average sea ice extent through 2005 and images of Beaufort Sea ice during winter and summer.

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Evaluation: (20 minutes)

1. Revisit the ladder of learning: What do you now know about sea ice?

2. Ask students to write the second rung of ladder in their science notebooks. There should be a lot more information now.

3. Use a “stand up–hand up–pair up” strategy to share student writing. Students will find a partner and then take turns reading and listening to what has been written for the second rung. Repeat sharing five times.

4. Walk around and listen to students exchanging ideas, making sure main points have been addressed.

5. Reiterate the main points once the sharing is completed, and add main points to class ladder of learning.

Ask students: What might be impacts both positive and negative about melting arctic sea ice?

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Teacher Preparation

Tips from Teachers

No tips are currently available.

Read through the entire investigation and the Teacher Background. Prepare to show the video and PowerPoint (optional) to the class. Gather materials for student investigations.

Make copies of handouts and provide graph paper.

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Curricular Connections

Math: Graphing and statistics

Literacy: Science Notebooks

Social Studies: Mapping, Ice Age

Technology: Excel graphing, Internet searching

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Materials Needed for Investigation 1:
Student Handouts	Science notebooks Arctic sea ice data Scatterplot example Sea ice flip book
Items for Group Display	video “Alaskan Native Thoughts on Climate Change” video "George Divoky: The BirdWatcher Who Saw the Future” Shrinking Ice Headlines PowerPoint Sea ice animation
Material Items	Graph paper 1B: Melting Sea Ice and Sea Level For each pair of students: Water 1 clear plastic 6-8 oz. cup Permanent felt-tip marker or tape Ice cube 1C: Temperature and Sea Level Rise Conical flask Two-hole cork for flask Thin glass tube Long thermometer Portable clamp-on reflector lamp 150-watt floodlight Dye or food coloring Graph paper
Facility/Equipment Requirements	Projector and/or computers to view online videos and PowerPoint Internet access Chart paper or board

Alaska Science Standards and Grade Level Expectations Addressed:

6th Grade:
The student demonstrates an understanding of the processes of science by
SA1.1 asking questions, predicting, observing, describing, measuring, classifying, making generalizations, inferring, and communicating.*
SA1.2 collaborating to design and conduct simple repeatable investigations. (L)

The student demonstrates an understanding that solving problems involves different ways of thinking by
SE2.2 comparing the student’s work to the work of peers in order to identify multiple paths that can be used to investigate a question or problem. (L)

7th Grade:
The student demonstrates an understanding of the processes of science by
SA1.1 asking questions, predicting, observing, describing, measuring, classifying, making generalizations, inferring, and communicating.*
SA1.2 collaborating to design and conduct simple repeatable investigations, in order to record, analyze (i.e., range, mean, median, mode), interpret data, and present findings. (L)

The student demonstrates an understanding that solving problems involves different ways of thinking by
SE2.2 comparing the student’s work to the work of peers in order to identify multiple paths that can be used to investigate a question or problem. (L)*

The student demonstrates an understanding that scientific knowledge is ongoing and subject to change by
SG3.1 revising a personal idea when presented with experimental/observational data inconsistent with that personal idea (e.g., the rates of falling bodies of different masses).* (L)

8th Grade:
The student demonstrates an understanding of the processes of science by:
SA1.1 asking questions, predicting, observing, describing, measuring, classifying, making generalizations, inferring and communicating.*
SA1.2 collaborating to design and conduct repeatable investigations, in order to record, analyze (i.e., range, mean, median, mode), interpret data, and present findings.* (L)

The student demonstrates an understanding of the attitudes and approaches to scientific inquiry by
SA2.1 recognizing and analyzing differing scientific explanations and models.

The student demonstrates an understanding of the forces that shape Earth by:
SD2.1 interpreting topographical maps to identify features (i.e., rivers, lakes, mountains, valleys, islands, and tundra).

The student demonstrates an understanding that solving problems involves different ways of thinking by
SE2.2 comparing the student’s work to the work of peers in order to identify multiple paths that can be used to investigate and evaluate potential solutions to a question or problem. (L)

The student demonstrates an understanding of how scientific discoveries and technological innovations affect our lives and society by:
SE3.1 predicting the possible effects of a recent scientific discovery, invention, or scientific breakthrough. (L)

The student demonstrates an understanding that scientific knowledge is ongoing and subject to change by
SG3.1 revising a personal idea when presented with experimental/observational data inconsistent with that personal idea (e.g., the rates of falling bodies of different masses). (L)*

Essential Questions: How do changes in physical environment affect our ecosystem? What impacts will climate change have on Alaska Seas and Watersheds? Enduring Understandings: Climate patterns cause physical changes in the environment. Physical changes in the environment can change the conditions for life. Science and technology can be used to detect and solve problems.