canopy heat storage not scaled by vegetation fraction

[barlage]

when calculating canopy heat storage term in vegetation flux iteration, the term should be scaled by vegetation fraction to be consistent with the radiation scaling in the solution:

https://github.com/NCAR/noahmp/blob/ac6848be386811364c1e15337673b134993f74b5/src/SurfaceEnergyFluxVegetatedMod.F90#L302

For example, when the term is not scaled, the vegetation temperature will depend on vegetation fraction:

without canopy heat scaling, fveg = 0.1: tv = 310.48472113867035
without canopy heat scaling, fveg = 0.9: tv = 309.36242868601590

with canopy heat scaling, fveg = 0.1: tv = 309.27431763431838
with canopy heat scaling, fveg = 0.9: tv = 309.27431763431838

[AlbaraaKhayat]

Hello, What is the modification to the line so that we could fix it in our implementation? Thank you

[barlage]

I'm still working in the non-refactored code, so this is the proposed fix. Didn't want to put in a PR until I could get something working with refactored code (don't know when that will be).

Related to this line in the non-refactored code:

https://github.com/NCAR/noahmp/blob/e1b83ad4c55e5e186be1cf726a222c78d6abdcc2/src/module_sf_noahmplsm.F#L4051

 ! canopy heat capacity
-        hcv = fveg*(parameters%cbiom*vaie*cwat + canliq*cwat/denh2o + canice*cice/denice) !j/m2/k
+        hcv = parameters%cbiom*vaie*cwat + canliq*cwat/denh2o + canice*cice/denice !j/m2/k

[cenlinhe]

This is indeed a bug. I will fix it in the GitHub develop and master branch as well as the version 4.5 used in WRFv4.5.

[cenlinhe]

The canopy heat storage term needs to be scaled by vegetation fraction (FVEG) because all the other heat flux terms in the energy balance calculations are scaled by FVEG.

[tslin2]

I am closing this issue based on the above discussions.

[barlage]

@cenlinhe @tslin2 for future reference there should be a way to automatically close the issue when the PR is merged.

[dmocko]

I believe if you put the following in your commit message as part of the PR, the issue will automatically close when the PR is merged into the main branch:

Resolves: #[issue number]

See the example commit message here: https://cbea.ms/git-commit/#seven-rules