This project has been separated into 2 sections: results and source code

results
  - contains all the data used and images produced in the project.  It does
    not contain the original NSCAT data, but rather the divergence calculated
    from the original NSCAT data and various others.

code
  - contains all IDL and scripts used to produce the data, manage the data,
    and produce the images.

Notation used throughout project:
  div2grid
    - term used to abbreviate the process of calculating the divergence first
      from the NSCAT winds, then gridding the divergence values.
  grid2div
    - term used to abbreviate the process of gridding the NSCAT winds, then
      calculating the divergence.

Steps taken in project:
  1) div2grid is computed:
    a) The divergence of every point in the NSCAT dataset was calculated using
       the method described in Sonya Kulkarni's paper "Variablility of Surface
       Wind Convergence."  The program used to calculate the divergences is
       code/computing/calc_nscat_div.pro  The inner radius used =1.75 degrees
       and the outer radius used =2.25 degrees.

            center X = point of divergence value

                                       .*---*.          --
                                     *'   |   `*         |
                          --       .'   .*-*.   `.       |
                         |        /   *'  |  `*   \      | outer radius
            inner radius |       /   '    |    `   \     |
                         |      *   /     |     \   *    |
                          --    |--|------X------|--|   --
                                *   \     |     /   *
                                 \   `.   |   .'   /
                                  \    *  |  *    /
                                   `.   `._.'   .'
                                     `.   |   .'
                                       `*---*'

    b) The files used to save the divergence values (before averages are
       computed) are compressed to save disk space.  When they were originally
       produced the format of the output files was not taken into account, and
       each file ended up consuming over 30MB of disk space.  The current
       method is still not the best, but each data file only consumes 4 to
       5 MB a piece now.  The files were compressed with the Perl script
       code/compress.pl  The format of these files is described in the
       dataformat.txt file.
    c) The compressed data files are then used to create daily, weekly, and
       monthly gridded divergence averages depending on the timestamp of each
       swath.

  2) grid2div is computed:
    a) Original NSCAT winds are gridded based on weekly and monthly averages.
    b) NSCAT gridded winds are used to calculate divergence using the
       traditional method of du/dx + dv/dy.  dy and dx =4.0 degrees

                 * = point of divergence value

                 du = valueAt(x1) - valueAt(x2)
                 dv = valueAt(y1) - valueAt(y2)
                 dy = y1 - y2
                 dx = x1 - x2

                                    y1
                                     |
                                     |
                                     |
                               x2----*----x1
                                     |
                                     |
                                     |
                                    y2

  3) Plots of both datasets are made on a weekly and monthly basis:
    a) Both values of divergence (div2grid and grid2div) values are plotted
       separately.
    b) The difference of grid2div - div2grid is plotted
    c) A zonal average along the latitude lines is plotted for the tropical 
       regions of the Atlantic, Indian, and Pacific oceans.  These zonal
       averages are plotted for div2grid, grid2div, and the grid2div - div2grid
       difference plot.