How to use specified localization scale values in JEDI-MPAS 1.0.0

JEDI
1

Hi there,

I am reading the paper

https://doi.org/10.5194/gmd-2022-133

and my colleague is trying to follow the tutorial on Running the JEDI-MPAS Variational Application

https://jointcenterforsatellitedataassimilation-jedi-docs.readthedocs-hosted.com/en/1.2.0/learning/tutorials/level2/envar-mpas.html

on using 3DEnVar.

On the paper, it was mentioned that fixed localization scale values, like 1200 km and 6 km for the horizontal and vertical full widths, can be used. In the Supplement of the paper, I see that in jedi-mpas.yaml, there is an item

background error:
localization:
bump:
prefix: bumploc_1200km_6km

so I guess the 1200 km and 6 km horizontal and vertical full widths settings are specified via some bumploc_1200km_6km*.nc files.

Question: I would wonder how to specify fixed localization scale values to use in 3DEnVar. Is it via some way [Step 5: Generate a localization file (optional), using mpasjedi_parameters.x] to generate these bumploc_1200km_6km*.nc in the ensemble EnVar framework, or is it from some 3DVar? Also, does the JEDI-MPAS v1.0.0 release have this feature, or we need to use another version of JEDI-MPAS code?

I’ll appreciate a lot if anyone shed light on it. Thank you very much!

Best Regards,
Chris

2

Hi @chrischeung ,

Thank you for your interest on JEDI-MPAS.

Question: I would wonder how to specify fixed localization scale values to use in 3DEnVar. Is it via some way [Step 5: Generate a localization file (optional), using mpasjedi_parameters.x] to generate these bumploc_1200km_6km*.nc in the ensemble EnVar framework, or is it from some 3DVar? Also, does the JEDI-MPAS v1.0.0 release have this feature, or we need to use another version of JEDI-MPAS code?

Yes, the localization files can be generated with separate executable mpasjedi_parameters.x. This is a part of JEDI-MPAS v1.0.0 release. You can find some generic description here Getting started — JEDI Documentation 1 documentation .

The yaml file in step 5 diagnoses the localization lengths from ensemble samples. So, if the users want to specify the localization lengths, the yaml file (parameters_bumploc.yaml) should be configured accordingly. Please try to modify parameters_bumploc.yaml as followings:

Under bump key,

  new_hdiag: 0
  forced_radii: 1
  rh:
    temperature: [1200.0e3]
    spechum: [1200.0e3]
    uReconstructZonal: [1200.0e3]
    uReconstructMeridional: [1200.0e3]
    surface_pressure: [1200.0e3]
    common: [1200.0e3]
  rv:
    temperature: [6.0e3]
    spechum: [6.0e3]
    uReconstructZonal: [6.0e3]
    uReconstructMeridional: [3.0e3]
    surface_pressure: [6.0e3]
    common: [6.0e3]

Thank you,
BJ

3 Likes
3

Dear BJ,

It works! Thanks for your help!

Best Regards,
Chris

1 Like