Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Introduce prognostic updraft velocity in saSAS and C3 convection #914

Open
wants to merge 1 commit into
base: develop
Choose a base branch
from

Conversation

lisa-bengtsson
Copy link
Contributor

@lisa-bengtsson lisa-bengtsson commented Jan 23, 2025

Description

This development incorporates a new prognostic updraft velocity equation into the saSAS deep and shallow convection schemes. It is introduced as a module and will be easily added to the C3 scheme as well, once the modularized C3 code is in place.

The equation describes the time-evolution of convective updraft velocity, with buoyancy as a source term, and quadratic damping is due to aerodynamic drag and mixing/diffusion and linear damping from wind shear.

The equation is discretized using an implicit approach, and solved as a quadratic equation. For implementation details - please see: https://docs.google.com/document/d/13VH7DV4erJcuuF_-dUGpplk9uYHF6dalfx8l1fAIxe8/edit?tab=t.0

The prognostic updraft velocity is used in the prognostic closure if progsigma = true and progomega = true, it is also replacing the diagnostic updraft velocity in the adjustment time-scale computation if progomega = true (regardless of progsigma). I here implement the scheme using the default setting of progomega = false for further testing and evaluation, and thus no regression tests should fail and no new baselines are required.

Do PRs in upstream repositories need to be merged first?
If so add the "waiting for other repos" label and list the upstream PRs

Requirements before merging

  • All new code in this PR is tested by at least one unit test
  • All new code in this PR includes Doxygen documentation
  • All new code in this PR does not add new compilation warnings (check CI output)

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

A new prognostic updraft velocity module for cumulus convection
1 participant