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Can WPS model heights be extended above 1Pa?


New member
Hello everyone,
I am trying to run WRF with Initial and lateral boundary conditions which are derived from WACCM(National Center for Atmospheric Research Whole Atmosphere Community Climate Model) . The model top of WACCM is about 5.9 × 10-6 hPa (∼145 km). When I use WPS to generate the met_em.d01.*.nc file, the top level of the file can only reach 1Pa.
Can the WPS be modified to extend the top? If it can be modified, please provide me a clue? Thanks a lot!
Jia Zhu
Hello everyone,
I followed the 'Writing Meteorological Data to the Intermediate Format' section in the user's guide to generate the Intermediate FILE. It can reach a top above 1Pa. But the met_em.d01.*.nc, which is generated by the metgrid.exe, got a top level limiting to 1Pa. I have checked the code (read_met_module.F,write_met_module.F), but didn't find the variables to modifie about the top level. If you can kindly give me some advices? Thank you so much!
Jia Zhu
Processing data with model tops lower than 1 mb is possible in WPS. This can be done by setting the namelist variable "pmin" in &ungrib section. For e.g.,
pmin = 1.

However we don't know if the model can handle model pressure tops much lower than 1 mb or 45 km in height. We don't have any experience in this regard. You can give it a try, but it may not work well.

You may also need to compile WRF with double precision. To do this, issue the following before recompiling.
./clean -a
./configure -r8