An example yaml for one-step bump to create stddev

JEDI
1

Hi, folks,
In the existing fv3jedi tests, to use bump to create stddev files , there are multiple steps to be carried out including some prep steps like staticb_prep. While those preps and following calculation are not as clear to me as I hope for ( though thanks to my colleague A. Tangborn’s helpful explanation), I am wondering if experts on this could provide a yaml example to use the straightforward one-step procedure as described in Getting started — JEDI Documentation 1 documentation by using the block as

bump: # (continued)
  new_var: 1                       # Run VAR driver
  ne: 10                           # Ensemble size
  var_filter: 1                    # Activate variance filtering
  var_niter: 3                     # Number of iterations for the variance filtering
  var_rhflt: 1000.0e3              # Initial radius for the variance filtering

This one-step way would give me the stddev that works and with less gray zone factors.
Thanks

2

Hi @TingLei-daprediction , it looks like this documentation is very outdated: the yaml keys of BUMP were all updated in January (https://github.com/JCSDA-internal/saber/pull/389). The yaml section you are citing is creating a new variance field from 10 ensemble members, and filtering horizontally with 3 iterations, starting with a 1000 km radius.

3

@benjaminmenetrier Thank you so much!. This yaml file seems the variance files could be generated in one step , which is easier than the two step procedure as shown in current fv3jedi ctests for regional aero . Is this option still working ? if yes, that will be great if you could point me to such an example.