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How to replace ALBEDO and LAI ,VEGFRA fields using Noah LSM ?

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Dear expert:

I used Noah LSM in my simulation . now I want to change the VEGFRA, LAI and Albedo data sets with my high-resolution remote sensing data updated every 8 days from MODIS(in tiff format). (PS: 2 years simulation from 2000-2001) I have prepared all the data and projected them to match the WRF grids. From this post:

it seems I need to process my data and put them in the WPS_GEOG directory or change geo_em file .

But many other articles suggested making change to wrflowinp files. So can you give me some thoughts on this ? Thank you

You can rewrite your data in the static data format, which is recognized by WPS, then process them by geogrid.exe. Note that you will also need to modify REAL (dyn_em/module_initialize_real.F) to process these 8-day data so that they can be correctly incorporated into wrflowinp file.

The other option is that you can modify the wrflowinp file, to make it include these data. This also involves pre-processing of the data at 8-day intervals.

Personally I believe the second option might be easier.
Thanks very much for your swift reply. I tried the second opiton. I make changes to VEGFRA and LAI in wrflowinp_d02, but after the execution of wrf.exe. ,the VEGFRA and LAI in wrfout files didn't change at all. I'm very confused about it. Here is what I do to namelist.input and the version of my WRF is WRFV3.8.1. I also attach the namelist.input. Hope to know why .

add in the physics:

sst_update = 1,
rdlai2d = .true.,
usemonalb = .true.,

Thank you



  • namelist.input
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Did you also change VEGFRA and LAI in wrflowinp_d01? Are you looking at wrfout_d01 or wrfout_d02?
No. Since I'm only interested in the inner domain,I just change VEGFRA and LAI in wrflowinp_d02, and I want the default value in WRF to be used for the outer domain d01. VEGFRA and LAI in wrfout_d02 are the same as I did not set sst=1 and rdlai2d to be true.
When feedback is turned on, IVGTPY (together with terrain, soil types etc.) from the nest will overwrite coarse domain values. Feedback from categorical data is different from continuous fields such as terrain. When sst_update is on, those fields read in from wrflowinp file should also overwrite the parent domain values based on the same rule.

Note sst_update should be the same for all domains, i.e., you need to produce wrflowinp_d01, too. I am not sure whether the missing of wrflowinp_d01 is the reason for the weird results you have seen.