MODIS land cover datasets used in CLM

[subha_s2s]

Dear Sir/Madam,

I find that there are 17 PFT types in the dataset mksrf_pft.nc. PFT type 17 stands for bare ground, so there is no corresponding LAI, SAI and vegetation HTOP or HBOT data for PFT type 17 in the mksrf_lai.nc dataset.
However, I found that PFT type-1 i.e. NET temperate (z=1) doesn't have corresponding LAI or SAI data in mksrf_lai.nc, whereas LAI, SAI data exists for other PFT types (z=2 to z=16). Can anybody please help me to understand the reason for this mismatch?
I also wonder how does the CLM read the LAI, SAI dataset corresponding to each PFT type if there is a mismatch of this sort !

Thanks in advance to all,

with best regards,
Subhadeep.

 

[slevis]

In the clm code the pfts are indexed 0 to 16, and in the file they are indexed 1 to 17. So bare ground is pft0 in the code and pft1 in the file. Either way, bare ground is the first pft. The last pft is generic crop2 and is not used in most cases.

Sam Levis
CLM Science Liaison

 

[subha_s2s]

Dear Sir,

I have another query.
If the percentage cover of a certain PFT type is increased or decreased in a certain domain in the global PFT dataset, then how can I change its corresponding LAI in that domain ?
I see that each PFT type has its own annual cycle of LAI ans SAI, but I don't know of any relation between a PFT type and its corresponding LAI/SAI.

Any suggestions or help is welcome and appreciated.

with regards,

Subhadeep Halder
PhD student
India.

 

[slevis]

LAI is measured in m2 leaf area per m2 pft area on the ground. The fractional cover of a pft in a grid cell is independent of the LAI. For example, in one grid cell you may have 10% and in another 20% cover by c3 grass and yet the LAI in both cases could be the same.

Sam Levis