@BeginModule
@NewPage
@Name      = Afterburner
@Title     = ECHAM standard post processor
@Section   = Miscellaneous
@Arguments = ifiles ofile
@Operators = after
@EndModule


@BeginOperator_after
@Title     = ECHAM standard post processor

@BeginDescription
The "afterburner" is the standard post processor for ECHAM data which provides the following operations:
@BeginItemize
@Item = Extract specified variables and levels
@Item = Compute derived variables
@Item = Transform spectral data to Gaussian grid representation
@Item = Vertical interpolation to pressure levels or height
@Item = Compute temporal means
@EndItemize
This operator reads selection parameters as namelist from stdin.
Use the UNIX redirection "< namelistfile" to read the namelist from file.

Namelist parameter and there defaults:
@BeginListing
  TYPE=0, CODE=-1, LEVEL=-1, MEAN=0, INTERVAL=0, TIMESEL=-1, UNITSEL=0, EXTRAPOLATE=0
@EndListing

TYPE controls the transformation and vertical interpolation. Transforming spectral data to Gaussian grid representation
and vertical interpolation to pressure levels or height are performed in a chain of steps. The TYPE parameter may be used 
to stop the chain at a certain step. Valid values are:

@BeginListing
  TYPE  =  0 : Hybrid             level spectral coefficients
  TYPE  = 10 : Hybrid             level fourier  coefficients
  TYPE  = 11 : Hybrid             level zonal mean sections
  TYPE  = 20 : Hybrid             level gauss grids
  TYPE  = 30 : Pressure or Height level gauss grids
  TYPE  = 40 : Pressure or Height level fourier  coefficients
  TYPE  = 41 : Pressure or Height level zonal mean sections
  TYPE  = 50 : Pressure or Height level spectral coefficients
  TYPE  = 60 : Pressure or Height level fourier  coefficients
  TYPE  = 61 : Pressure or Height level zonal mean sections
  TYPE  = 70 : Pressure or Height level gauss grids
@EndListing


Vorticity, divergence, streamfunction and velocity potential need special treatment in the vertical transformation.
They are not available as types 30, 40 and 41. If you select one of these combinations, type is automatically
switched to the equivalent types 70, 60 and 61. The type of all other variables will be switched too, because 
the type is a global parameter.
@EndDescription
@EndOperator


@BeginExample
To interpolate ECHAM hybrid model level data to pressure levels of 925, 850, 500 and 200 hPa, use:
@BeginVerbatim
   cdo after ifile ofile << EON
      TYPE=30  LEVEL=92500,85000,50000,20000
   EON
@EndVerbatim
@EndExample
