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change SMOIS and TSLB in ideal test

W

water

New member
Hi, WRF support:
The fact that SMOIS and TSLB in the wrfout became 0 over the ocean after I added some land in an ideal experiment seems unreasonable to me. Could you please explain the reason for this? Attached is a figure.
The second question: I would like to know the most effective way to modify surface roughness and soil moisture in an ideal test. My current approach is to change the underlying surface vegetation type without modifying Z0. Is this approach correct?
 

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  • SMOIS.png
    SMOIS.png
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Apologies for the delay in response to this. It does seem as though it fell through the cracks, so thank you for the reminder. I'm going to run this by a colleague and will get back to you.
 
kwerner said:
Apologies for the delay in response to this. It does seem as though it fell through the cracks, so thank you for the reminder. I'm going to run this by a colleague and will get back to you.
Click to expand...
No problem, if you need more detailed information from me, please feel free to let me know.
 
Hi,
I asked our physics expert about this and they said that these arrays don't matter over the ocean, so the initialization probably forced them to zero. They asked with LSM you're using, and stated that the roughness can easily be changed in the corresponding *.TBL file (that's associated with the LSM you're using).
 
kwerner said:
Hi,
I asked our physics expert about this and they said that these arrays don't matter over the ocean, so the initialization probably forced them to zero. They asked with LSM you're using, and stated that the roughness can easily be changed in the corresponding *.TBL file (that's associated with the LSM you're using).
Click to expand...

Thank you very much for your response. If I don't include land, the initial field has SMOIS=1 over the ocean. However, when I introduce land, the value becomes zero. According to your advice, is this change correct?

Additionally, if I want to maintain a fixed soil moisture value during the simulation, how should I proceed?
 
water said:
If I don't include land, the initial field has SMOIS=1 over the ocean. However, when I introduce land, the value becomes zero. According to your advice, is this change correct?
Click to expand...
In the sea breeze case setting SMOIS should be included in the land part of the domain. You can use that as an example.

water said:
Additionally, if I want to maintain a fixed soil moisture value during the simulation, how should I proceed?
Click to expand...
Are you using an LSM or simple slab? If you're using the slab, it has a fixed moisture availability from LANDUSE.TBL. Or are you wanting a full LSM?
 
kwerner said:
In the sea breeze case setting SMOIS should be included in the land part of the domain. You can use that as an example.


Are you using an LSM or simple slab? If you're using the slab, it has a fixed moisture availability from LANDUSE.TBL. Or are you wanting a full LSM?
Click to expand...
Yes, I used LSM. sf_sfclay_physics=1(revised MM5 Monin-Obukhov);sf_surface_physics=2(unified Noah)
 
I spoke to the physics specialist again. They said they think you need to add a loop after the LSM to reset SMOIS to the wanted value at every time step.
This can be done in the surface driver where there are some loops after the LSMs. Hopefully that's helpful!
 
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