Question about Noah-MP vegetation parameters and LAI source

[Setareh Rahimi]

Dear WRF Support Team,

I am currently using WRF v4.6.0 with the Noah-MP land surface model (sf_surface_physics = 4) for winter simulations (January) over a complex mountainous region.

As part of a sensitivity study, I would like to modify several vegetation-related parameters in MPTABLE.TBL, including:

• Leaf Area Index (LAI)
• Stem Area Index (SAI)
• Roughness length (Z0MVT)
• Vegetation height (HVT)
• Other vegetation parameters available in Noah-MP

However, I am uncertain about how Noah-MP determines which vegetation parameters are actually used during the simulation.

I understand that WRF also generates vegetation-related fields (such as LAI and vegetation fraction) through the WPS/geogrid preprocessing system (geo_em, met_em, and wrfinput). At the same time, Noah-MP contains monthly vegetation parameters in MPTABLE.TBL.

My objective is to perform sensitivity experiments by modifying the values in MPTABLE.TBL. Therefore, I would like Noah-MP to use these modified values instead of the vegetation fields provided by the geogrid input.

Could you please clarify the following questions?

1. When using Noah-MP (sf_surface_physics = 4), under what conditions does the model read LAI, SAI, roughness length, vegetation height, and other vegetation parameters from MPTABLE.TBL, and under what conditions does it use the corresponding fields from geo_em/met_em/wrfinput?
2. Is there a namelist option (for example, dveg or any other option) that explicitly controls whether LAI comes from MPTABLE.TBL or from the input geogrid files?
3. If I modify LAI_JAN, SAI_JAN, Z0MVT, HVT, and other vegetation parameters in MPTABLE.TBL, what additional steps are required to ensure that Noah-MP actually uses these modified values during the simulation? For example, do I need to regenerate geo_em, met_em, or wrfinput, or is rerunning real.exe sufficient?
4. Is there any recommended way to verify from the WRF output or log files that Noah-MP is indeed using the modified values from MPTABLE.TBL rather than the vegetation information contained in the input files?

Thank you very much for your time and assistance.

Best regards,

[Mary Barth]

Hello Setareh,

FYI, this Google group is for questions about running the WRF-Chem model, specifically for the NCAR-supported chemistry options.

Please post your question on the WRF Forum. 

- Mary

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Mary Barth 

Senior Scientist, NSF National Center for Atmospheric Research   

phone: 303-497-8186    email: bar...@ucar.edu

NSF NCAR Staff web page       MUSICA Web Site  

International Commission on Atmospheric Chemistry and Global Pollution

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[Setareh Rahimi]

Dear Mary,

Thanks for your email. Actually, this is part of my WRF-Chem simulation. I also sent the questions on https://forum.mmm.ucar.edu/. But I did not receive any answers.

So it would be great if someone here could help me with this.

Thanks in advance.

--

S.Rahimi