Is base state pressure PB infinitely constant in time?

[Rick]

I'm saving a LOT of wrfout data, over a thousand years' worth. I'm trying to prune out some data fields which are redundant. I am saving a single, complete wrfout file to access these constant fields in the future.

In my pruned down archive, in order to compute total pressure I'm saving P, and to compute geopotential height I'm saving PH. Am I correct that for the same model domain and vertical levels PB and PHB are constant? So I can use those fields from my single archived wrfout file to reconstruct the actual pressure and geopotential on the model vertical levels?

 

[Ming Chen]

You are right that for the same case, PB and PHB remain unchanged during the integration period. Thereby, you can always use these variables extracted from any single wrfout file to calculate pressure and geopotential height.