Dynamic annual land use adjustments in CLM

[CGL]

Hi, CESM team!
I'm a bit confused about how to adjust the forest Fraction annually. In CESM, there are PCT_NATVEG and PCT_NATVEG_PFT. As far as I understand, PCT_NATVEG is the land use data determined at the start year when CESM is initiated(in fsurdat ).

The landtime series file only contains the variable PCT_NATVEG_PFT. For example, if in a certain year later, I convert all cropland and grassland to forest, how should I make the adjustment? Is it by setting the PFT corresponding to forest in PCT_NATVEG_PFT to 100? And what about PCT_CROP, should that be adjusted as well?

my CESM version is 2.1.3, CLM version is CLM5.

Thanks for your help!

 

[Yuan Sun]

Hi, CESM team!
I'm a bit confused about how to adjust the forest Fraction annually. In CESM, there are PCT_NATVEG and PCT_NATVEG_PFT. As far as I understand, PCT_NATVEG is the land use data determined at the start year when CESM is initiated(in fsurdat ).

The landtime series file only contains the variable PCT_NATVEG_PFT. For example, if in a certain year later, I convert all cropland and grassland to forest, how should I make the adjustment? Is it by setting the PFT corresponding to forest in PCT_NATVEG_PFT to 100? And what about PCT_CROP, should that be adjusted as well?

my CESM version is 2.1.3, CLM version is CLM5.

Thanks for your help!

Though landuse data does not have PCT_NATVEG, the model will calculate the PCT_NATVEG in transient compset. That means PCT_NATVEG is not only determined by fsurdat.

Setting PCT_CROP to zero might work.

Best,
Yuan

 

[slevis]

You may find this explanation useful:

ctsm5.3 landuse_timeseries PCT_* variables

Hi, I am now using CTSM5.3 and trying to modify landuse data in the IHIST case's Landuse_timeseries file. I found that the PCT_* variables are different from those of CLM5. In CLM5, surfdata requires that the sum of all PCT_* variables (should) be 100. But I didn't find any requirement about...

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