This directory contains all the IDL files used to calculate the divergence
from the NSCAT data and grid the datasets (weekly and monthly).

calc_grid_div.pro
  - calculate divergence using the traditional method of du/dx + dv/dy.  This
    is not a runnable program, it is just a procedure to be called and
    divergence will be returned.
calc_nscat_div.pro
  - This program is used to calculate divergence at each valid point in the
    NSCAT dataset.  The data is read in by calling read_NSCAT_winds.  The
    array of latitudes, longitudes, winds directions, wind speeds, and
    dimensions of the arrays are returned.  From here the divergence of every
    point in the dataset is calculated using the same methodology used by
    Sonya C. Kulkarni in her paper "Variablility of Surface Wind
    Convergence", also known as the "Doughnut method".
div2grid_daily.pro
  - This program takes a daily divergence file which is in the format
    previously specified for this project and grids each file.
div2grid_monthly.pro
  - This program takes a daily divergence file which is in the format
    previously specified for this project and grids it based on the month of
    the swath.  Each monthly value is then used to calculate the monthly
    average of each month in the NSCAT mission.
div2grid_weekly.pro
  - This program takes a divergence file which is in the format previously
    specified for this project and grids it based on the week of the swath.
    Each weekly value is then used to calculate the weekly average of each
    week in the NSCAT mission.
getytdata.pro
  - Extracts the appropriate data from either the grid2div or div2grid
    datasets and saves it in the location specified by the user.  This data
    will later be used by ytplot.pro under the plotting directory.
grid2div_month.pro
  - This program is used to calculate the divergence from a gridded dataset.
    In this case it is reading a NSCAT data that has been already gridded and
    will then be output to a file.  This is also only computed divergence for
    the monthly NSCAT dataset.
grid2div_week.pro
  - This program is used to calculate the divergence from a gridded dataset.
    In this case it is reading a NSCAT data that has been already gridded and
    will then be output to a file.  This is also only computed divergence for
    the weekly NSCAT dataset.
nscat2grid_month.pro
  - This program takes the NSCAT dataset grids it and finds the monthly
    averge based on the month of each swath.  Some of the data files contain
    swaths that are in one month and other swaths in the next month.  All
    these exceptions are checked when finding the monthly average.  Once a
    month is completed it is output to file.
nscat2grid_week.pro
  - This program takes the NSCAT dataset grids it and finds the weekly averge
    based on the week of each swath.  Some of the data files contain swaths
    that are in one week and other swaths in the next week.  All these
    exceptions are checked when finding the weekly average.  Once a week is
    completed it is output to file.
read_NSCAT_winds.pro
  - Reads in a NetCDF NSCAT file and returns the data to the caller.
readfile.pro
  - This subroutine reads one of the gzipped divergence files and returns
    the data, times, and dimensions of the data.