Kristine DeLong

Louisiana State University

Undergraduate and graduate students who have a background in Earth science. Prerequisites for course include Physical Geography or Physical and Historical Geology. This is an elective class for undergraduate majors and a seminar course for graduate students at the 4000 level. My current class is a 2 hour class that meets twice a week with 8 students.

Students will need basic map reading and interpretation skills. They need to be familiar with internet web browsers. The students should have experience with reading peer-reviewed science papers.

This is an in-class activity with an introductory lecture on the CLIMAP project and the Last Glacial Maximum. This activity occurs after discussing glacial-interglacial cycles and Milankovitch orbital hypothesis. I assign a reading before class, Chapter 12 in Earth's Climate – Past and Future by William Ruddiman. The classroom needs computers with internet browsers, internet access, and Adobe Acrobat Reader (for skimming papers).

Understand the differences between modern climate conditions and the LGM as reconstructed in the CLIMAP study.

Allow students to explore the CLIMAP model results for differences between the modern and LGM so they discover the how climate and vegetation may have changed in different regions of the Earth.

Engage the students in critical scientific thought by discussing the assumptions made in the CLIMAP study in 1976 and 1984 compared to what we know now about climate change since the LGM.

Students further develop their skills reading scientific papers by quickly skimming the original CLIMAP papers for the assumptions used in the LGM model reconstruction [CLIMAP (1976), the surface of the ice-age earth, Science, 191(4232), 1131-1137; CLIMAP (1984), The last interglacial ocean, Quaternary Res., 21(2), 123.]

Short lecture on CLIMAP project (see PowerPoint) 20 minutes

• Powerpoint (PowerPoint 444kB Nov7 10)

Group activity - Reading for CLIMAP study assumptions, 20 minutes to read, 20 minutes for discussion

• Student Handout (Microsoft Word 50kB Nov7 10)

Students break into groups (4 per group is good division of work) with 2 students per paper. Split the assumptions between students. Each group skims the CLIMAP papers for the assumptions (modern and/or LGM) used in the CLIMAP model-based reconstruction of the LGM. In the groups, students compare the assumptions between papers.

Resources: CLIMAP (1976), The surface of the ice-age earth, Science, 191(4232), 1131-1137 and CLIMAP (1984), The last interglacial ocean, Quaternary Research, 21(2), 123.

Class Discussion - Summarize assumptions used in CLIMAP studies.

Group activity – Exploring CLIMAP LGM Reconstructions, 40 minutes for model data, 20 minutes for discussion (Could be modified with as a "jigsaw" activity with a larger class). Learn more about the jigsaw teaching method.

Students work on this activity in pairs; one person will create LGM maps, the other modern. Students should sit together with their computer monitors close together to compare. The students will use the IRI/LDEO Climate Data Library to access the CLIMAP reconstruction and produce maps using the tools available on this web site. In a web browser, go to http://iridl.ldeo.columbia.edu/SOURCES/.CLIMAP/

This is the main page for the CLIMAP Model output for the LGM 18,000 BP. In the middle of the page is the label "Datasets and variables" with two data sets below http://iridl.ldeo.columbia.edu/SOURCES/.CLIMAP/.LGM/ and http://iridl.ldeo.columbia.edu/SOURCES/.CLIMAP/.MOD. Each student clicks on the link they are assigned to. There are several data sets listed for each period and the students will examine each data set and compare the LGM and Modern. As a class, go through each data set allowing pairs to compare the maps then summarize the results as a class. The worksheet has a table for the students and the PowerPoint has table for summarizing.

Class Discussion - Summarize differences between modern and LGM in the CLIMAP model output. Discuss how the assumptions of the CLIMAP model studies may have influenced the results.

Extra activities

1. The students can explore the data further using the data selection and filters in the IRI/LDEO Climate Data Library. For the two SST data sets, click on "Data Selection" and narrow the data to the just the tropics (23.5º N-S). Click on "Filters" then select XY next to "Average over."
   
   The next window gives you the average over the tropics close to the top of the page.
   
2. In the next class, the students repeat the Readings exercise by reading the COHMAP and MARGO papers to see how the scientific knowledge has progressed since the original CLIMAP studies.

COHMAP Members, (1988), Climatic Changes of the Last 18,000 Years: Observations and Model Simulations, Science, 241(4869), 1043-1052.

MARGO (2009), Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum, Nature Geoscience, 2(2), 127-132.

Assignment or exam question: Ask the students to compare their results from the model output exercise with those described in the CLIMAP papers and in the textbook.

Assignment or take home exam question: Ask students how they would redesign the CLIMAP study base on what we know today about the LGM? What different assumptions would they use and what variables would they examine in order to further the state of knowledge of glacial to modern climate change.