1. shell script

  diag.sh:
    controls execution of plots.
    creates configuration file (conf.ncl) in the current directory
    then draws plots based on conf.ncl using ncl.

2. Setting files

  dict_xy.ncl:
    dictionary for surface plots
    associates plotid with contour levels, variable names and level
  dict_yz.ncl:
    dictionary for lat-pres plots
    associates plotid with contour levels, variable names and top level
  dict_ty.ncl
    dictionary for lat-time plots
    associates plotid with contour levels, variable names and level
  dict_obs.ncl:
    dictionary of obs_varname correspoding to each varname
  dict_model.ncl
    dictionary of scale factors corresponding to each model varname

3. Files for I/O

  io_model_grd.ncl
    defines functions to read a variable from a GrADS file
  io_model_nc.ncl
    defines functions to read a variable from a netCDF file
	io_geo.ncl
    defines a function to read surface index from geodir from file Grads.ctl

4. ncl scripts for plot 

  plot_xy.ncl:
    draws contours and vectors in either cylindrical equidistant or
    polar stereographic projections
  plot_yz.ncl:
    draws zonal mean in meridional cross-section
  plot_ty.ncl
    draws annual cycle
  plot_tr.ncl
    draws annual heat transport

4. steps to create plots and web
  - Preare monthly means in GrADS or netCDF (one variable per file).
  - Edit diag.sh. Set directories.
  - Run the script.