BETTING ON CLIMATE CHANGE

Transcription

1 Overview: Students will compare breakup records from the Tanana River, in Alaska, recorded by the Nenana Ice Classic, to the timing of bud burst in the Interior and speculate about the relationship between the seemingly unrelated data. Objectives: The student will: create a spreadsheet in Microsoft Excel using data from two different events; construct a graph including trendlines using the chart wizard in Excel; and evaluate and analyze two data sets to find a common influence. (NOTE: This lesson is intended to accompany the UNITE US mentor lecture by Anupma Prakash titled, Earth Systems: How Everything is Connected, found at ) Targeted Alaska Performance Measures Tested on the Alaska High School Qualifying Exam (HSQE): Math M6.3.1 Collect, analyze, and display data in a variety of visual displays including frequency distributions, circle graphs, histograms, and scatter plots. M6.3.4 Make projections based on available data and evaluate whether or not inferences can be made given the parameters of the data. M Apply mathematical skills and processes to science and humanities. Targeted Alaska Grade Level Expectations: [11] SA1.1 The student develops an understanding of the processes of science by asking questions, predicting, observing, describing, measuring, classifying, making generalizations, analyzing data, developing models, inferring, and communicating. [11] SE1.1 The student demonstrates an understanding of how to integrate scientific knowledge and technology to address problems by researching how social, economic, and political forces strongly influence which technology will be developed and used. Vocabulary: breakup the breaking of ice on lakes and rivers in the spring bud burst the emergence of new leaves on a plant at the beginning of each growing season climate change a change in the statistical distribution of weather over periods of time that range from decades to millions of years climatology the scientific study of climates, including the causes and long-term effects of variation in regional and global climates freeze-up the time of year when rivers and lakes freeze over; the onset of winter Julian day a simple form for stating the day of the year using numbers 1 to 365 (366 in leap years) phenology the scientific study of cyclical biological events, such as flowering, breeding, and migration, in relation to climatic conditions river a large, natural stream of fresh water that flows into an ocean, a lake, or another body of water, usually fed by smaller streams that flow into it Whole Picture: The Athabascan word Nenana means, a good place to camp between rivers. For centuries the area s indigenous people used the river and Toghetthele Hill, which sits above the town, as a traditional gathering place for hunting, fishing, trade, meetings and celebrations. Toghetthele means, the hill next to the river. PFG-119

2 In 1917 railroad workers settled in the area began a friendly competition to guess the date and time the ice would break up on the Tanana River at Nenana. The winner-take-all pot of money was $ Every year since, people try to guess the exact date and time the Tanana will breakup. A tripod is placed on the river in October or November, planted in two feet of river ice. The tripod is connected by string to a clock on the shore. Movement of the tripod triggers the clock to stop. The city of Nenana has dutifully kept records of each breakup. This data can be used as a non-traditional data set, meaning that the original intent was not a scientific study, but the data set lends itself well to climate change comparisons. View the original data set at under Nenana Ice Classic: Tanana River Ice Annual Breakup Dates. Click on Access Data, then nenana.dat to review breakup dates beginning in Many factors influence when the ice will breakup on the river. Air temperature, ice thickness, snow cover, wind, water temperature, and depth of water below the ice are all important variables. The average thickness of the ice on April 1 is 42 inches. All over Alaska Athabascans look forward to the break up of rivers and lakes because when the ice leaves, access to the food source is regained! Air temperature is thought to be the main environmental factor regulating the timing of bud burst in the boreal forest. Bonanza Creek Long-Term Ecological Research records bud burst each year as a part of ongoing research intended to document the major controls over forest dynamics, biogeochemistry, and disturbance and their interactions in the face of a changing climate. Materials: Student computers equipped with Microsoft Excel and Internet access DIGITAL LECTURE: Climate Change: A Complex Issue MULTIMEDIA: Nenana Ice Classic and Fairbanks Bud Bursts VISUAL AID: Ice Breakup on the Tanana River Versus Bud Burst in Fairbanks STUDENT LAB SHEET: Activity Preparation: 1. On a white board or piece of chart paper, write the following: Air temperature, ice thickness, snow cover, wind, water temperature and water depth. 2. Bookmark the UNITE US site, on student computers. Set up the multimedia projector so that you can review the necessary page with students. 3. Work through STUDENT LAB SHEET: to familiarize yourself with the process. Activity Procedure: 1. As a class, watch the DIGITAL LECTURE: Climate Change: A Complex Issue, found at uniteusforclimate.org/ and discuss. Consider the following critical thinking questions to begin the discussion: a. Name one way the talk by Nancy Fresco changed the way you think about climate change. b. Do you think it is possible to study one climate change issue, in isolation, without considering others? c. Is it possible for people to influence climate change? Explain. d. If people can influence climate change, can it be positive OR negative? e. What evidence of global climate change can be seen on Earth? f. Are greenhouse gases the only thing affecting global climate? g. Why can t we predict the exact future of Alaska s climate? 2. Explain students will compare two separate data sets to see if they find any correlation. One data set comes from The Nenana Ice Classic. Ask students if they are familiar with the competition held each spring since (See Whole Picture.) The second data set comes from a study by Bonanza Creek Long-Term Ecological Research, located in the boreal forest of interior Alaska. PFG-120

3 To save time, both data sets have been copied to the UNITE US website. For the next section, students will use computers to access the data, create an Excel file and accompanying graph of the data. Show students the two pages they will use to complete STUDENT LAB SHEET: : Bud Burst Data Bonanza Creek LTER and Tanana River Breakup Nenana Ice Classic. Explain scientists use the Julian day to make it easier to compile data, so students will be doing the same. The Julian day assumes January 1 is day one and counts each day of the year thereafter through 365 (366 in leap years). 3. Hand out STUDENT LAB SHEET:. Ask students to work at computers to complete the assignment. The directions are on the lab sheet. 4. When students have completed lab sheet, Part 1, display VISUAL AID: Ice Breakup on the Tanana River versus Bud Burst in Fairbanks for Part 2. When students have completed Part 2, discuss the results. a. What trend do you see? b. Do you think ice breakup and bud burst are related? Does one cause the other? Does one affect the other? c. Looking at the list on the board (see Activity Preparation), what do you think is the common influence on ice breakup and bud burst? Is there more than one? d. About how much time is there between ice breakup and bud burst? e. What might account for some of the major dips or peaks on the graph? Any ideas? f. What other kinds of things could be compared to breakup and bud burst? g. Did the activity help you determine what date you might choose on an Ice Classic ticket? Why or why not? Extension Ideas: Carefully examine the graph showing the correlation between ice breakup and bud burst. Ask students to find years that dip or peak, then research the weather for that year to see if there is an explanation. Research other websites that give long-term weather. See what other data can be added to the graph. Visit the Bonanza Creek Long-Term Ecological Research website at to investigate and report on other kinds of long-term studies that may help us understand climate change. Additional Resources: Visit the GLOBE website (Global Learning and Observations to Benefit the Environment) at gov/ and enter the search term bud burst to access Bud Burst Protocol. Answers: STUDENT LAB SHEET: Student graphs may vary in format, but should indicate the correct input of data and look similar to the one shown at right. 18. Answers may vary. If student completed the graph as directed, the graphs should look similar. 19. Students should indicate bud burst and breakup data lines are almost parallel, indicating a possible relationship between when the ice melts and when trees green. 20. Answers may vary. Later class discussion will indicate air temperature. 21. The trendline for both breakup and bud burst indicate warmer temperatures are occurring earlier in the spring Answers will vary PFG-121

4 Section 1 Computer Work Directions: Follow the steps outlined below to create a graph in Excel that shows both the dates for the breakup of the Tanana River each spring and the dates when leaf buds open in Interior boreal forests. 1. Access the UNITE US website and find two pages: Bud Burst Data Bonanza Creek LTER and Tanana River Breakup Nenana Ice Classic. Keep these pages open. 2. Open a new Excel workbook. Name your file and save it. (Be sure to periodically save your work.) 3. Label Cell A1 Year, Cell B1 Breakup and Cell C1 Bud Burst. 4. Fill in the Year column starting at 1976 and continuing through You can use a shortcut to do this. Fill in the first year, 1976, in Cell A2 (right under the Year heading.) Highlight that entry then drag the highlight down to row 35. In the toolbar, select Edit, then Fill, then Series. When the box pops up (see right), check column and linear. Make sure the Step value remains 1. (You want one year at a time.) In the Stop value enter 2009 (the final year of your data). Click OK. You now should see a list of years from 1976 through 2009! 5. Working from the data on the UNITE US website, fill in the columns for breakup and bud burst using the Julian day. It should look like this 6. Select/highlight the data for Year, Breakup and Bud Burst, including headings, then click on Chart Wizard on the Excel toolbar. The Chart Wizard button on the toolbar looks similar to this: PFG-122

5 7. Choose XY (Scatter) graph, then the option to have markers displayed at each data value connected by lines. Click Next. 8. Excel has now captured the range of data you are using, shown in the Data range window. Click Next. PFG-123

6 9. Give your chart a title that describes the data being compared. 10. Label your (X) axis Year and your (Y) axis Julian Day. Click Next. 11. Place chart as a new sheet. Click Finish. 12. Right click (or double click if you don t have a two-button mouse) on the (Y) axis and choose Format Axis. Click on the Scale tab. Enter 100 as the minimum and 150 as the maximum. (This is the general range for the Julian Days.) Click OK. PFG-124

7 13. Your graph should look like this: 14. Right click (or double click if you don t have a two-button mouse) on the graph line for budburst. Choose Add Trendline. Under Type, choose Linear. Click OK. 15. Repeat the process for the graph line for breakup. PFG-125

8 16. Now your graph should look like this: Extra 17. If time permits, you can do some extra formatting. Data line: Right click (or double click if you don t have a two-button mouse) on Budburst data line and choose Format Data Series. Here you can choose a color for the line and for the data markers. You can even change the shape of the data markers if you wish. Repeat for Breakup data line. Trendline: Right click (or double click if you don t have a two-button mouse) on the Trendline and choose Format Trendline. Here you can change the Trendline to a dashed line or other line of choice and even change the color. Background: Right click (or double click if you don t have a two-button mouse) on the background (away from lines) and choose Format Plot Area. Here you can change the background color. Be sure to save your work!! PFG-126

9 Section 2 Written Work 18. Compare your graph to the graph displayed by your teacher titled Ice Breakup on the Tanana River versus Bud Burst in Fairbanks. This graph comes from Professor Dave Verbyla, Department of Forest Sciences School of Natural Resources and Agricultural Sciences, University of Alaska Fairbanks. How does your graph compare with Professor Verbyla s? 19. What does the graph indicate? What is the correlation between ice breakup and bud burst? Explain. 20. To what might you attribute any correlation you see? 21. What do the trendlines show? 22. Based on your graph, make a prediction about the day of ice breakup on the Tanana River in future years: 23. How might the results of your trendline affect the day you would choose if you were entering the Nenana Ice Classic in future years? PFG-127