Bug Fix to Explicit In-Canopy Vertical Diffusion of Tracers

[iri01]

Description

Remove hpbl/kpbl update due to explicit in-canopy diffusion. This ensures no changes on the SRW-App AQM predictions of temperature, humidity, and winds in regions of contiguous canopies due to explicit in-canopy diffusion. The integrated-canopy vertical diffusion meteorology effects remains as before.

Using 10-interpolated winds in the initialization of the explicit canopy layers (instead of the 1 hydrid model layer winds) for the diffusion of tracers. This leads to further reductions in ozone biases (and it's precursors) in regions on contiguous canopies.

Testing

Tests conducted on Gaea-C6 with the SRW-App AQM configuration/compilers. Tests conducted for GFS v16 and GFS v17_p8 physics.

Upcoming PR tests...

• Will the code updates change regression test baseline? If yes, why? Please show the baseline directory below.
• Please commit the regression test log files in your ufs-weather-model branch

Dependencies

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

• waiting on: Bug fix explicit in-canopy diffusion of tracers. ufs-community/ccpp-physics#371
  Upcoming full RT in UWM PR

[drnimbusrain]

@BrianCurtis-NOAA @dustinswales We would kindly request a high priority review of this bug fix . We are targeting getting this fix into UWM for UFS-AQMv8 operations, which has plans to start retro runs in May. Dependent on ccpp PR ufs-community/ccpp-physics#371

Thank you!

[iri01]

I'm running RT tests on ursa.. will upload RT info soon.

[gspetro-NOAA]

@iri01 @drnimbusrain The CCPP PR was merged. Please revert .gitmodules and update the CCPP physics hash to a57d1a6.

[gspetro-NOAA]

@iri01 @drnimbusrain Could you please update the ccpp-physics hash and revert .gitmodules? We need to wrap up ufs-community/ufs-weather-model#3186 today.

[drnimbusrain]

Yes, will do as soon as possible. I am away from the office so hopefully, @iri01 can do it soon. Thank you, Patrick

…

On Wed, Apr 22, 2026, 12:05 PM Gillian Petro ***@***.***> wrote: *gspetro-NOAA* left a comment (NOAA-EMC/ufsatm#1091) <#1091?email_source=notifications&email_token=AGLFYNWJNDUUWMOG5VQ4EHT4XDUS3A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMRZG44DMNJSGEZKM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJNLQOJPWG33NNVSW45C7N5YGK3S7MNWGSY3L#issuecomment-4297865212> @iri01 <https://github.com/iri01> @drnimbusrain <https://github.com/drnimbusrain> Could you please update the ccpp-physics hash and revert .gitmodules? We need to wrap up ufs-community/ufs-weather-model#3186 <ufs-community/ufs-weather-model#3186> today. — Reply to this email directly, view it on GitHub <#1091?email_source=notifications&email_token=AGLFYNWJNDUUWMOG5VQ4EHT4XDUS3A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMRZG44DMNJSGEZKM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJNLQOJPWG33NNVSW45C7N5YGK3S7MNWGSY3L#issuecomment-4297865212>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AGLFYNTZ7AQLXX3OGJKHAPT4XDUS3AVCNFSM6AAAAACXRMCAAKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DEOJXHA3DKMRRGI> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[drnimbusrain]

@iri01 @drnimbusrain Could you please update the ccpp-physics hash and revert .gitmodules? We need to wrap up ufs-community/ufs-weather-model#3186 today.

@gspetro-NOAA Sorry for the delay, the .gitmodules and ccpp/physics have been reverted. Thank you.

[BrianCurtis-NOAA]

new changes look good to me

[BrianCurtis-NOAA]

@DusanJovic-NOAA could you review and approve/merge when ready?