Case Study 4.1- Reflecting on What is Happening to Greenland's Ice

During this activity, students will:

• Identify factors that contribute to differences in reflectivity on the Greenland ice sheet spatially and temporally.
• Analyze real 2000–12 reflectivity data for the Greenland ice sheet at a particular elevation to recognize patterns and changes.
• Compare 2000–12 reflectivity data from a variety of elevations on the Greenland ice sheet to determine spatial and temporal reflectivity changes.
• Assess qualitatively how reflectivity on the Greenland ice sheet has changed from 2000 to 2012.
• Consider which components of the system could be playing a role in the observed reflectivity change.

My goals in creating this activity were to:

• Provide students with an understanding of surface melting of the Greenland ice sheet as an ice loss mechanism, the prominence of this mechanism during the past decade as expressed in the data, and implications for future changes in the ice sheet.
   
• Facilitate student development of skills in reading and interpreting graphs and predicting changes in a natural system.
   
• Encourage students to reflect about the multiple components that may contribute to changes in a natural system and the role of uncertainty in our understanding of complex systems. Promote student consideration of the potential impacts of cryosphere changes on humans.

Educational level: introductory geology, meteorology, oceanography, or other geoscience-related course

Class size: can be adapted to serve a variety of class sizes. Ideally, students will be working in groups of two to four. For organizational purposes, consider establishing groups before beginning the activity to make sure that each person in the group gets a different albedo plot.

Class format: This activity is suitable for use in a lecture or lab setting.

Time required: approximately 1.25 hours

Special equipment: Each student should receive student activity sheets, a color copy of one of the albedo plots, and a color copy of the 2012 reflectivity anomaly map.

Skills or concepts that students should have already mastered before encountering the activity: Students should have a basic awareness of the location and size of the Greenland ice sheet before beginning the activity. As described in the teaching notes section, it will be useful to have brief discussions interspersed throughout the activity to facilitate students' understanding of the concept of albedo, environmental factors contributing to albedo variations, anomalies, etc.

This activity can be used:

• as an in-class activity;
• as a cryosphere or paleoclimate lab when combined with Unit 5;
• as part of the complete Climate of Change InTeGrate module.
   

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Case Study 4.1 Solution Set for Instructors -- private instructor-only file

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Shortened Version of Case Study 4.1 (Microsoft Word 2007 (.docx) 52kB Jan5 14)

Case Study 4.1 Images (PowerPoint 2007 (.pptx) 23.2MB Jun24 14)

• Regardless of whether or not students will complete Case Study 4.2, it is important to discuss the different mechanisms by which ice loss occurs across the Greenland ice sheet. Case study 4.1 emphasizes ice loss from areas between 500 and 3200 m. Case Study 4.2 emphasizes ice loss via marine-terminating outlet glaciers.
• Incorporating short regroups/discussions with the entire class throughout the activity will minimize the need for extensive lecturing, allow real-time assessment of student comprehension, and provide opportunities for guidance if necessary. In particular, students may need assistance coming up with ideas about why glacial ice may exhibit a wide reflectivity range and understanding the concept of a reflectivity anomaly.
• Some students will assume incorrectly that decreases in reflectivity indicate total melting down to bedrock. Some of the later questions in the student handout prompt students to consider that reflectivity data may be providing information about other components of the system other than the ice sheet itself (example: extent and timing of snowmelt).
• Although feedback loops will be explicitly addressed in Unit 5--systems@play, the end of Case Study 4.1 would be an appropriate time to introduce the concept and have students think about ice-albedo feedback without using the word feedback.

(1) Which of the following sets of conditions should result in the highest ice sheet albedo?

A. summer, low elevation, exposed ice sheet

B. winter, high elevation, snow covering the ice sheet

C. summer, high elevation, snow covering the ice sheet

D. winter, low elevation, exposed ice sheet

(2) Your instructor has provided you with a blank grid with months of the year on the x-axis and albedo (low vs. high) on the y-axis.

(a) Consider a high-latitude area north of the equator, such as Greenland. On the grid, make a sketch illustrating how surface albedo in this area changes during the year.
(b) Describe how the 2012 albedo data for the Greenland ice sheet varied for high elevation areas compared to low elevation areas.

Article: Greenland ice sheet getting darker from Ohio State University.

Article: Algae Drive Enhanced Darkening of Bare Ice on the Greenland Ice Sheet. Stibal et al., 2017, Geophysical Research Letters.
Google Earth file: Greenland Annual Surface Melt, 1979-2007 from the NSIDC. (KMZ file)
Earth Exploration Toolbook chapter: Is Greenland Melting? GIS activity from SERC's Earth Exploration Toolbook collection.