ASIS:Data thk

29/10/08: Joining ice thickness datasets together.

Step 1: Joined BEDMAP ice thickness (smoothed with a low pass filter) and AGASEA ice thickness. The diagram below shows the polygon used to join the datasets together, and the overlap region. The joining process used the arcinfo mosaic function, where it averages the two datasets in areas of overlap. I then applied a low pass smoothing filter to the overlap areas to smooth it out a bit.



Step 2: Joined grounded ice thickness to ice shelf thickness. The diagram below on the left shows an unsmoothed version. There are quite a few areas where there are large ice thicknesses in the shelves, where the ice is actually grounded, so is giving high values. In order to smooth these out, ice shelf cells which have a border with grounded ice were given the average value of the grounded ice thickness values (right hand diagram below). It doesn't remove all the problems, but it does a good enough job in the Amundsen Sea region.



15/08/08: This is the unmasked datset provided by Jon Bamber (13/08/08):



Previous data: This is the dataset provided by Jon Bamber for ice shelf areas. Again it is masked using Jon's mask, so it might cause some problems when joining it to the grounded ice thickness dataset.

This is a useful dataset, but I think Jon will need to provide the data without it having been masked, otherwise it will be difficult to join to the grounded ice data.