This assignment explores ice core data from 90,000 to 10,000 years before present. The data include carbon dioxide and methane concentrations and a measure of the ratio of oxygen isotope 18 to oxygen isotope 16 (called “d 18O” and pronounced “dell O 18”). These data come from the Greenland GISP2 and the Antarctic Byrd ice core; atmospheric CH 4 and CO 2 records are from the Byrd ice core. The data are contained in
data_file_paleoclimate_assignment.xls.
General guidance for graphing: Highlight just the numbers in columns A and B to generate the first scatterplot. Then right click in the scatterplot and click select data, click the plus button under legend series to add a new data series, type the name of the next climate variable, click and drag data in column D for the x axis, and then click and drag all data in column E to get the variable on the y axis. Click ok and repeat adding new data series for CO2 and CH4.
These two videos will help with chart making in Excel (plotting multiple x-y pairs in a scatter-plot in Excel; adding a secondary y-axis in Excel.)
Alternatively, you can use this ready-made plot of the data https://people.cas.sc.edu/carbone/202/assignments/Natural_climate_change/dO18graph.png
Present the following in a document:
Make a single graph in Excel, Numbers, or any other graphics program that plots all four climate records versus age for the period from 10,000 to 90,000 years before present (the CO 2 data only covers ~20,000 – 90,000 ka). On the figure. label the Last Glacial Maximum (LGM) and the Younger Dryas (YD) periods.
Identify on the two d 18O graphs which times suggest warmer temperatures and which suggest colder temperatures
Insuring that the time (x-axis) is aligned, discuss differences that you see between the two d 18O curves.
Is the CH 4 record more similar to the Greenland or the Antarctic temperature record?
Compare the CO 2 and CH 4 records. How are they different?
Calculate the rate of CO 2 increase (DCO 2/Dt) for one of the large, abrupt events. How does this compare to the rate of CO 2 change from the pre-industrial period (1750) to present
