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IFS Forecast field data

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I am starting work in the WRF model with initial data from the IFS model. In addition to the basic fields necessary for the WRF model, I additionally have the following fields in the 3D files (at model levels):

Specific cloud ice water content
Specific cloud liquid water content
Specific snow water content
Specific rain water content

In the manual for the WRF 4.2.2 model, I found that the model loads similar 3D fields, but these are:

Rain Water mixing ratio
Snow Water mixing ratio
Ich Water mixing ratio

Is there any method of converting the fields, eg converting the IFS field data "Specific rain water content" to the values "Rain Water mixing ratio" which correctly reads ungrib.exe and metgrib.exe. And of course the other fields I wrote about above are similar.

The described fields are available in the new version of the GFS model (Rain Water mixing ratio, Snow Water mixing ratio) to improve rainfall forecasting.
I will be grateful for any help.

What format are you meteorological data in? If they are in gribbed format, you could follow the format of the Vtable.RUCb file, and instead of the RUC data codes, use the ones for IFS for each field.
Thank you very much for your answer.
Yes my files are in GRIB1 and GRIB2 format. I am using GRIB files in GRIB1 format.
I checked the Vtable.RUCb file format. I checked the Vtable.RUCb file format. I found records in it that are for the fields:

153 | 109 | * | | QC | kg kg-1 | Cloud water mixing ratio | 0 | 1 | 22 | 105 |
170 | 109 | * | | QR | kg kg-1 | Rain water mixing ratio | 0 | 1 | 24 | 105 |
178 | 109 | * | | QI | kg kg-1 | Ice mixing ratio | 0 | 1 | 23 | 105 |
171 | 109 | * | | QS | kg kg-1 | Snow water mixing ratio | 0 | 1 | 25 | 105 |
179 | 109 | * | | QG | kg kg-1 | Graupel mixing ratio | 0 | 1 | 32 | 105 |

Do the fields listed in Vtable.RUCb contain the same values as the fields: Specific cloud ice water content, Specific cloud liquid water content, Specific snow water content, Specific rain water content? Or otherwise. Are they identical. Will ungrib.exe recognize them correctly?

In the attachment I have enclosed the result of using the "g1print.exe" software (ifs_model_level.txt). In this file there are fields: CRWC, CSWC, which are assigned codes grib1 75 and 76 respectively. If it is true that CRWC = QR, and CSWC = QS, then this is the incompatibility of the codes grib1. In Vtable.RUCb, QR is grib 170 and QS 171. In contrast, the CLWC and CIWC fields have grib codes 246 and 247, respectively, but their names do not appear as a result of using g1print.exe. In my opinion, ungrib.exe may not read these fields correctly. What can I do about it?



  • ifs_model_level.txt
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Hi Mariusz,
I apologize that I was not entirely clear in my previous message. What I meant was to use the Vtable.RUCb as a sort of starting template, and to modify it to match the information in your IFS files. You will want to change the code values in the Vtable to match the values of the desired variables in your IFS files. The names in your IFS files are not important. The ungrib program will only look for the matching codes and levels. As to whether the fields in your IFS files exactly match the fields listed in the RUCb Vtable, I'm not sure about that. For information about the specific input code, you'll need to refer to the source of the data to obtain answers.