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LAI doesn't change from initial conditions


New member
Hi there,

I posted this in the WRF-chem forum yesterday, but I realize this may be a better place for the question.

I'm running WRF-Chem v3.9.1 for a 6 month period over a region of the U.S., and the LAI (leaf area index) is not changing in time from the initial conditions. The magnitude and spatial distribution of LAI in the initial conditions makes sense, but the output remains the same in each wrfout file for the whole run. VEGFRA (vegetation fraction) is not changing either. I checked other variables e.g. soil moisture, temperature, and precip, and they all are changing and appear to be modeled correctly during the run.

I use the CLM4 sf_surface_physics option, and I tried a run with the NOAH option to see if the land surface option was the issue, but LAI and VEGFRA don't change in that case either.

I know that LAI data is being read in through the static data when I run WPS, and as far as I'm aware my geog_data_path in namelist.wps is correct. I did change the geog_data_res from default to 10m, which should be ok.

I ran this same set up with chemistry turned off, and the LAI doesn't change in that case either. So I'm not sure what's causing this.

I've included my two namelist options here. I'd appreciate any help!



  • namelist.wps.wps
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  • namelist.input.input
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For long term simulation (in your case, it is 6-month), please set sst_update =1. This option allows you to update surface information including LAI.

Note that you need to rerun REAL with sst_update =1
Hi Ming,

Thank you for pointing this out. I see that there is some information about this approach in the README.namelist file. Will this work regardless of the land surface option being used, including CLM4?