Using ICON data

[thiesh]

Hello All,

I was wondering if it would be possible to use meteorological netCDF (or grib2) files from the ICON model database. Or is it only possible to use the netCDF files from WRF-ARW.

Thanks and Cheers,
Thies

[alicec]

We do not maintain a converter specifically for ICON because we do not have regular access to it.
We have assisted in helping people get the api2arl to work for ICON grib2 files.
You could probably modify the arw2arl to work with other netcdf files.

Generally it takes a bit of knowledge of the format of your meteorological data (vertical level structure, variable names) and
how to map those to what HYSPLIT expects.
https://www.ready.noaa.gov/HYSPLIT_data2arl.php
https://www.ready.noaa.gov/hysplitusersguide/S141.htm

[thiesh]

Hey,

thank you so much for your answer! So it is theoretically possible to get the api2arl to work for ICON files?
And if I understand the links you posted correctly, I need to use a 'Meteorological Packing Configuration File' to modify the file. Although you don’t have a specific converter, is there already a configuration file I could use? You mentioned that others have already done the conversion.

[alicec]

Yes, it's almost certainly possible. The general steps to converting any meteorological dataset are the following

• 1. Identify the projection. HYSPLIT currently can handle a regular latitude longitude grid or conformal projection.
  2. identify how the vertical levels are represented. For instance the data may be on pressure levels or on hybrid levels.
  For example ERA5 data may be on pressure levels or on model levels as described here.
  https://confluence.ecmwf.int/display/CK ... ric+height. What kind of vertical levels are used needs to be described to HYSPLIT.
  3. map the variable identifiers in the meteorological data file to the HYSPLIT variable identifiers. For instance, in an ERA5 grib file the temperature as a short name of 't' and ID of 130 and in HYSPLIT this has an identifier of TEMP. See here https://www.ready.noaa.gov/hysplitusersguide/S141.htm for HYSPLIT meteorological variables.
  [\list]
  
  It is often not as simple as just finding someone else who has converted data from the same meteorological dataset. I'm not as familiar with ICON, but let's take ERA5 as an example. ERA5 can be downloaded on pressure or hybrid levels. Using the same setup for both would not work. There can also be other differences as often the grib2 or netcdf files people are converting are themselves post-processed in different ways from the original dataset.