Open sebvi opened 2 months ago
2024-05-02 notes: Sebastien presented the proposal; Sibylle proposed a different solution with entries set to missing instead (@SibylleK can you add details in comment below?); Sebastien it is preferred to have a new template instead of using an existing template
https://github.com/wmo-im/CCT/wiki/Teleconference.2024.June.4and5 notes:
Sebastien summarized the two options for moving forward (new template or set values to missing in existing template);
DECISION: move forward with new template;
branch created and updated according to DECISION
https://github.com/wmo-im/CCT/wiki/Teleconference.24and26.June.2024 notes: check branch;
You can find a branch of ecCodes implementing template 4.50 here: feature/ft2024-2_245
a sample is attached: 50.grib2.zip
https://github.com/wmo-im/CCT/wiki/Teleconference.2.July.2024 notes: @SibylleK will review the samples
Initial request
The template 4.44, Analysis or forecast at a horizontal level or in a horizontal layer at a point in time for aerosol is marked as operational, however it is recommended not to use this template: "PDT 4.48 Analysis or forecast at a horizontal level or in a horizontal layer at a point in time for optical properties of aerosol should be used instead with the optical wavelength range set to missing". The issue with template 4.44 is that the forecast time has only 2 octets instead of the usual 4 octets. This means that deterministic forecasts for aerosols use the template 4.48 which includes additionally keys for the optical wavelength (all set to missing to ignore them) while for probabilistic aerosol forecasts the aerosol-only template 4.45 can be used. This leads to a discrepancy in the layout of the same data coming from deterministic and probabilistic model runs.
We propose to deprecate the template 4.44 and properly create a new template 4.50 (instead of 4.48 with keys set to missing) with the forecast time having 4 octets as it is the case in the corresponding probabilistic aerosol template 4.45.
Amendment details
DEPRECATE template 4.44 and CREATE a corrected version as template 4.50.
ADD to code table 4.0 - Product definition template number
CREATE Template 4.50 - Analysis or forecast at a horizontal level or in a horizontal layer at a point in time for aerosol
Comments
No response
Requestor(s)
ECMWF
Stakeholder(s)
ECMWF
Publication(s)
Manual on Codes (WMO-No. 306), Volume I.2, GRIB code table 4.0 (update) Manual on Codes (WMO-No. 306), Volume I.2, GRIB Template 4.44 (deprecate) Manual on Codes (WMO-No. 306), Volume I.2, GRIB Template 4.48 (create)
Expected impact of change
MEDIUM
Collaborators
Sebastien Villaume (ECMWF) Robert Osinski (ECMWF)
References
No response
Validation
No response