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ERA5 invariable drive the model


New member
ERA5 data is in the format of each variable per file, which is different from other traditional input data sources. However, processing it through ungrib isn't that much different. You will simply link all files - both upper air and surface data - into your working directory and ungrib will be able to handle it, using Vtable.ECMWF. The one thing you'll need to do differently is to include the invariant data file. You can either download it from the site where you obtain all your ERA data, or we've also attached it to this post. You need to place it in your WPS working directory.

Do we also need to change the start and end time in namelist.wps?

Thank you
Yes you need to change time when you ungrib invariant data file, and the time should be consistent with the time of the invariant datafile.

After those invariant variables (i.e., landmask and soilhgt) are extracted and written to a separate intermediate file, this intermediate file that contains the two constant fields can be specified with the constants_name variable under &metgrid, and WPS will process this file and ignore its time.