Post processing tools

Standard Post-Processing

CDO is a very useful tool for postprocessing SOCOL output, e.g. for calculating averages, interpolation to pressure levels, selection of variables, time steps, etc.: https://code.mpimet.mpg.de/projects/cdo/

• cdo is already installed on the IAC Linux system and can be loaded by module load cdo

The classical post processor for ECHAM data is the "afterburner" which provides the following operations:

• Extract specified variables and levels
• Compute derived variables
• Transform spectral data to Gaussian grid representation
• Vertical interpolation to pressure levels or height
• Write data in GRIB, NetCDF, SERVICE or EXTRA format
• User manual: afterburner.txt
• Afterburner source code and Makefile: after.tar
• The cdo command after does the same as the afterburner, and is easier to use!!!

Calculation of Residual Circulation and EP-fluxes

The calculation of the residual circulation and the EP-fluxes follow Andrews (1987): https://iac-twiki.ethz.ch/pub/Chemie/PostProc/Andrews_1987_p127ff.pdf

Required Input

• daily mean or 6 hrly (better) instantaneous 3D T [K], u [m/s], v [m/s], omega [Pa/s] on pressure levels [Pa]
• ATTENTION: the namelist setting PUTDATA   = 24, 'hours', 'first', 0 outputs instantaneous values every 24 hours, not daily averages!!! That leads to artefacts in the calculated TEM in the mesosphere. If you intend to calculate the residual circulation from your model output, set PUTDATA   = 12, 'hours', 'first', 0 or better PUTDATA   = 6, 'hours', 'first', 0
• cdo script for preparing input data for epf routine from model output: https://iac-twiki.ethz.ch/pub/Chemie/PostProc/make_epf_vars_netcdf.sh

EPF-Routines

• Using a temperature-dependent density: https://iac-twiki.ethz.ch/pub/Chemie/PostProc/epf_from_daily_v3.f90
• Using a fixed scale height of H=6950 m and log-pressure altitude: https://iac-twiki.ethz.ch/pub/Chemie/PostProc/epf_from_daily_v4.f90
• NOTE: Although CCMI recommended a fixed scale height, we used a temperature-dependent density to calculate the residual circulation and EP-fluxes from the CCMI simulations!!!

Other Useful Scripts

• Compiling epf routines: https://iac-twiki.ethz.ch/pub/Chemie/PostProc/compile_epf_from_daily.sh
• Script to postprocess several months: https://iac-twiki.ethz.ch/pub/Chemie/PostProc/calc_ep-flux.csh

CMOR (Climate Model Output Rewriter)

CMOR is a "handy" data post-processing tool originally designed to produce datasets conforming to CMIP conventions. It has since been adapted by the CCMI community for CCMI-1. CMOR stands for Climate Model Output Rewriter.

• Laura's CMOR documentation: https://iac-twiki.ethz.ch/pub/Chemie/PostProc/CMOR_SOCOL_documentation.pdf
• Laura's CMOR scripts: https://iac-twiki.ethz.ch/pub/Chemie/PostProc/cmor_scripts.tar