intermediate files does not include the fields on the 0.01 hPa isobaric levels from GFS grib2 data.

[BJ Jung]

Hi WRF/WPS users and wrfhelp,

I'd like to get some guidance to "ungrib" the GFS's higher level isobaric fields.

In my understanding, GFS grib2 format file includes the higher level isobaric fields up to 0.01 hPa since March 22, 2021. In my testing, however, the intermediate file generated from "ungrib.exe" only includes the isobaric fields up to 1 hPa.

When I see the attached "g2print.log" file, the GFS grib2 file contains the isobaric dataset in the higher level (up to 0.01 hPa, for example, UGRD, TMP, HGT,... variables). In the attached "ungrib.log" file, however, it only processes the isobaric fields up to 1 hPa.

Can you guide me if I miss some namelist option (my "namelist.wps" also attached) or configuration to process the higher level isobaric fields?

I am using the precompiled WPS V4.6.0 on Derecho. If it is helpful, you can find my working directory on Derecho: /glade/derecho/scratch/bjung/Bflow/HTsampleData/01_ungrib/work_forum

Thank you,
BJ

 

[kwerner]

Hi BJ,

I believe this is because WPS has a setting for the variable pmin, which is the minimum pressure that will be extracted from isobaric datasets. The default value for pmin is 100 Pa. You can set this to a different value in the &ungrib namelist.wps record.

 

[BJ Jung]

Hi @kwerner,

Thank you for your explanation! Setting "pmin" as 1 Pa has fixed my issue. I should have checked all namelist options from WPS! --BJ

 

[kwerner]

That's great! And no worries - it's difficult to read through all the available options.