SO503, Spring 2007

Lab, Sea Ice Thickness

The paper by Wensnahan and others (2007) describes newly available data on sea ice thickness in the Arctic.  This data is available at http://nsidc.org/data/g01360.html .

We have the international bathymetric chart of the Arctic Ocean (http://www.ngdc.noaa.gov/mgg/bathymetry/arctic/arctic.html) on which to plot the results. Get the file from http://www.usna.edu/Users/oceano/pguth/microdem/win32/ibcao.zip and then unzip it to avoid some formatting issues.

1. Download the file you have been assigned.
2. Uncompress the file.  This uses Unix compression.  Winzip can probably deal with this, as can MICRODEM (see its help file).
3. Select one of the resulting cruise segments.
4. Process the segment so that you can get a graph of the sea ice thickness (could be done in MICRODEM or Excel), and plot the segment on a map (MICRODEM).
5. Share your files with the other members of the class.
6. Write a proposal for how you would use this data to trace global climate change.  This is a writing requirement, for which you should have three references (the executive summary of the global climate change study, the EOS paper, and the documentation of the data set on line).  You should also have at least two figures.

IBCAO with the trace of one submarine segment overlaid.

	Graph of the ice thickness from the segment above. Note that the y axis is inverted (very common for geology and oceanography), which MICRODEM does but Excel does not. Note that the points are not connected, since the program cannot assume they are in sequential order.
	Graph of the ice thickness for a subset of the segment above. This connects the points, because the plot was of a time series with equally spaced, sequential readings.