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.

Sign up for GitHub

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

Jump to bottom

opposite direction of ground heat flux in urban models with Noah-MP land surface model #114

Closed
tslin2 opened this issue Oct 7, 2023 · 5 comments
Closed

opposite direction of ground heat flux in urban models with Noah-MP land surface model #114

tslin2 opened this issue Oct 7, 2023 · 5 comments
Assignees
@cenlinhe
Labels
bug Something isn't working

Comments

@tslin2
Copy link
Collaborator

tslin2 commented Oct 7, 2023 •
edited
Loading

The ground heat flux in Noah-MP is downwards positive from surface, but it is downwards negative from surface in Noah land surface model (LSM).

To keep the same direction of ground heat flux between urban models (SLUCM, BEP, or BEM) and the land surface model (Noah or Noah-MP) is required to calculate surface energy balance at the grid mean level.

In Noah LSM, the ground heat flux direction is the same as urban models, but differ in Noah-MP.

To make the same direction using SLUCM with Noah-MP LSM at the grid mean level.

hrldas/urban/wrf/NoahmpUrbanDriverMainMod.F

Line 530 in f550db9

GRDFLX(I,J) = FRC_URB2D(I,J) * (G_URB) + (1-FRC_URB2D(I,J)) * GRDFLX(I,J) ![W/m/m]

should revise to
GRDFLX(I,J) = FRC_URB2D(I,J) * (-1.0 * G_URB) + (1-FRC_URB2D(I,J)) * GRDFLX(I,J) ![W/m/m]

and for BEP, BEM

hrldas/urban/wrf/NoahmpUrbanDriverMainMod.F

Line 759 in f550db9

grdflx(i,j) = (1.-frc_urb2d(i,j))*grdflx_rural(i,j)+ frc_urb2d(i,j)*grdflx_urb(i,j)

should revise to
grdflx(i,j) = (1.-frc_urb2d(i,j)) * grdflx_rural(i,j)+ frc_urb2d(i,j) * grdflx_urb(i,j) * -1.0
@tslin2 tslin2 changed the title opposite direction of ground heat flux in urban model with Noah-MP opposite direction of ground heat flux in urban models with Noah-MP land surface model Oct 7, 2023
@cenlinhe
Copy link
Collaborator

cenlinhe commented Oct 8, 2023

@tslin2 Could you please double check BEP and BEP-BEM? I remembered that in these two models, the sign is correct? Maybe I remembered it wrong.

@cenlinhe cenlinhe self-assigned this Oct 8, 2023
@cenlinhe cenlinhe added the bug Something isn't working label Oct 8, 2023
@tslin2
Copy link
Collaborator Author

tslin2 commented Oct 8, 2023

@cenlinhe
my simulation results show that in Noah with urban models, the GRDFLX has the same direction in urban and rural areas, but is opposite between rural and urban areas in Noah-MP with urban models including using SLUCM, BEP, or BEP-BEM.

@cenlinhe
Copy link
Collaborator

cenlinhe commented Oct 8, 2023

OK, we need to fix this then in both hrldas and wrf. You may also want to open a WRF issue to point out this issue.

@tslin2 tslin2 mentioned this issue Oct 8, 2023
Open
@cenlinhe
Copy link
Collaborator

I confirmed this bug.
The ground heat flux is positive for downward direction in Noah-MP: https://github.com/NCAR/noahmp/blob/master/src/SurfaceEnergyFluxBareGroundMod.F90#L155
the ground heat flux is negative for downward direction in SLUCM: https://github.com/NCAR/hrldas/blob/master/urban/wrf/module_sf_urban.F#L1503
and BEP: https://github.com/NCAR/hrldas/blob/master/urban/wrf/module_sf_bep.F#L3287
and BEP_BEM: https://github.com/NCAR/hrldas/blob/master/urban/wrf/module_sf_bep_bem.F#L5312

@cenlinhe
Copy link
Collaborator

This bug has been fixed in this commit for v5.0: a3ce25e
and in this commit for v4.5: NCAR/noahmp@a26f91f
Here I am closing this issue.

@cenlinhe cenlinhe mentioned this issue Oct 22, 2023
Merged
weiwangncar pushed a commit to wrf-model/WRF that referenced this issue Jan 13, 2024
@cenlinhe
Bug fix for Noah-MP snow, vegetation and urban (#1929)
ce1069f 
TYPE: bug fix

KEYWORDS: Noah-MP, snow combine, vegetation fraction scaling, urban ground heat flux

SOURCE: Cenlin He (NCAR/RAL)

DESCRIPTION OF CHANGES:
There are a few bug fixes for Noah-MP related processes:
(1) the snow layer index in snow COMBINE module was wrong, causing model crash when snow layer changes by more than 1 layer within one timestep; This has been fixed by using the correct layer index. 
(2) the ground heat flux sign in Noah-MP column model (positive: downward) is inconsistent with that in urban canopy model (positive: upward), leading to wrong diagnostic grid-mean ground heat flux calculation for urban grid. This only affects the diagnostic value for output. See this issue: #1921 and NCAR/hrldas#114
(3) there is a bug in vegetation fraction (FVEG) scaling for stomata resistance calculation (NCAR/noahmp#92) and canopy interception calculation (NCAR/noahmp#91).

LIST OF MODIFIED FILES: list of changed files (use `git diff --name-status master` to get formatted list):
phys/noahmp/src/module_sf_noahmplsm.F
phys/noahmp/src/module_sf_noahmpdrv.F

TESTS CONDUCTED: 
1. Tested successfully in NCAR Cheyenne HPC for 13-km run over the entire CONUS region
2. The Jenkins tests are all passing.

RELEASE NOTE:  Noah-MP bug fix for snow combination, vegetation fraction scaling, and urban ground heat flux sign.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees

@cenlinhe cenlinhe

Labels
bug Something isn't working
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
2 participants
@cenlinhe @tslin2