NCAR / NCAR/DART

feat: bug: fug: mom6 perturbation model specific perturbation

Open
#730 4 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

mom6
Dominant language
Fortran
Stars
263
Forks
182
Avg merge
11d 12h
Merged PRs (30d)
7

Description

Perturbing MOM6 to get some ensembles to play with.
Currently (lazily) using the default perturbation routine, which perturbs everything in the state including land.

This gives some fuzz on the land:

c.TL319_t232.001
Screenshot 2024-09-05 at 4 25 36 PM

nwa12_test.3_0_a03a
Screenshot 2024-09-05 at 4 28 47 PM

Compare to non-fuzz before perturbation
Screenshot 2024-09-05 at 4 33 00 PM

who cares?
You'll inflate the land because mean /= 0 (adds more fuzz), get_close makes 'dry' state far away so the assimilation update doesn't change the land, but still I think dangerous to fuzz.
See https://github.com/NCAR/DART/issues/359 for missing_in_state comment that I have not rewritten yet. https://github.com/NCAR/DART/issues/359#issuecomment-2332614632

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by locating the default MOM6 perturbation routine referenced in the issue and read the discussion in NCAR/DART issue 359, especially the linked comment. Define the MOM6-specific perturbation scope from that context, then verify that ensemble perturbations no longer add fuzz to land while intended state perturbations remain.

Written by the indexing model from the issue text.

Assessment

Tech stack
fortran
Domain
data
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Active
Clarity
Mostly clear
Newbie friendliness
48/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.