Interfaces & Tools#

Zonda: ICON Grid & EXTPAR Interface#

../_images/zonda.png

Zonda is a web interface designed to facilitate the generation of External Parameter data (EXTPAR) on ICON triangular grids for research and on-demand simulations. This is realized as a two-step process:

  1. In the frontend, the user specifies the domain(s) including the appropriate settings for the external parameter generation. Example configurations and a expert mode with additional choices are available to assist the user. As a result, the user gets a JSON code snippet which is required for the second step.

  2. In the backend, the JSON code has to be pasted into a github issue. Then, the github CI triggers the generation of the ICON Grid and EXTPAR data.

Zonda Access

Zonda is free to use, the only requirement is a github account. The Zonda web interface is available under https://zonda.ethz.ch/ and comes with documentation.

Please note that the grids and EXTPAR data generated by Zonda are targeted at the NWP physics package.

Coupling (YAC)#

YAC (Yet Another Coupler) is a flexibe coupling library which comes with ICON. Its interface is compatible to the well known OASIS coupler and it can be used as a full replacement of it. YAC supports many different horizontal interpolations and a unique interpolation stack to control alternatives in case direct interpolation is not feasable. It is not only used for coupling atmosphere and ocean components of ICON, but also for a highly flexible output method.

yac yac

YAC Documentation

You can find further information in the YAC Documentation.

Data Analyslis & Remapping (CDO)#

CDO is a well know data anlysis tool developed by Max-Planck-Institute for Meteorology. CDO supports the ICON native horizontal grid so that ICON model output can be easily analysed.

Examples:

  • Horizontal interlations can be done with a wide range of methods

  • Vertical interpolation from ICON (atm) vertical sigma hight coordinate with the ap2pl operator:

    • (optional) add CF-conform name for pressure with

    ncatted -O -a standard_name,pres,o,c,"air_pressure" <input> <output>     # using NCO

    or

    cdo -setattribute,pres@standard_name='air_pressure' <input> <output>

    • call the ap2pl operator in this case for a remapping to the 500 hPa and 825 hPa levels

    cdo ap2pl,50000,82500 <input> <output>
On this page