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Confusion about mksrf_flai when using custom landuse data

Jeline

New Member
Dear CLM scientists,

I am investigating the climatic effects of vegetation change and need to customize the land-use data for CLM. I have already created the land-use raw data using the clm5landusedatatool developed by Peter Lawrence, and I am now using mksurfdata_map to generate the surface data and land-use timeseries data that can drive the CLM model.

My question is:
When running mksurfdata_map, the default mksrf_flai file is
lnd/clm2/rawdata/pftcftlandusedynharv.0.25x0.25.MODIS.simyr1850-2015.c170412/mksrf_lai_78pfts_simyr2005.c170413.nc.
It seems that this file represents the global LAI distribution derived from MODIS for the year 2005.

If the land-use raw data I generated differs from the real-world vegetation distribution — for example, if I convert cropland in a certain region entirely into natural vegetation — do I need to regenerate the default mksrf_flai file so that it matches my customized land-use data?

If not, could you please explain why it is unnecessary?
If yes, how should the new mksrf_flai file be created?

Thank you in advance for your help.
 

Jeline

New Member
Sorry, everyone, I have one more question.
I have successfully generated a surface dataset using mksurfdata_map, but after comparing it with the official surface dataset provided by CESM, I noticed that my file is missing several variables:
  • binfl: VIC b parameter for the Variable Infiltration Capacity Curve
  • Ws: VIC Ws parameter for the ARNO curve
  • Dsmax: VIC Dsmax parameter for the ARNO curve
  • Ds: VIC Ds parameter for the ARNO curve
  • F0: maximum gridcell fractional inundated area
  • P3: coefficient for qflx_surf_lag for inundated areas
  • ZWT0: decay factor for inundated areas
Why are these variables missing from the surface dataset I generated?
Can a surface dataset without these variables still be used to run CLM normally?

Thank you very much for your help!
 

slevis

Moderator
Staff member
@Jeline I suggest not worrying about the mksrf_flai file, because you may find that the mksurfdata_map tool still assigns LAIs to your pfts, even when you move them from the 2005 distribution. If looking at the generated fsurdat file, you are unhappy with the LAIs assigned to your pfts, then consider updating the mksrf_flai file. Other than Peter Lawrence's tools, we do not supply official guidance for generating such file.

The variables that you asked about may be missing from your fsurdat because you didn't select the "vic" option when generating the file. If you do not plan to use "vic" in your simulations, then I think you'll be fine.
 

Jeline

New Member
@Jeline I suggest not worrying about the mksrf_flai file, because you may find that the mksurfdata_map tool still assigns LAIs to your pfts, even when you move them from the 2005 distribution. If looking at the generated fsurdat file, you are unhappy with the LAIs assigned to your pfts, then consider updating the mksrf_flai file. Other than Peter Lawrence's tools, we do not supply official guidance for generating such file.

The variables that you asked about may be missing from your fsurdat because you didn't select the "vic" option when generating the file. If you do not plan to use "vic" in your simulations, then I think you'll be fine.
Thanks for your response. I will check the content you mentioned.
 
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