How can I make change in PFTs?

[gustavocretton]

Hello everyone!
I intend to use the CESM to assess the mesoscale climatic effects of deforestation in Brazil. I created future deforestation scenarios for Brazil and I would like to insert them into the CLM. Which archives should I modify to change the PFTs? Is that possible to do it? Thanks in advance!

 

[oleson]

PFTs are prescribed by the surface dataset. The fsurdat in lnd_in points to this file. You can change pfts in that file. Natural pfts and crops are PCT_NAT_PFT and PCT_CFT, respectively. See Tables 2.2.1 and 2.26.1 for a numbered list of natural pfts and crops, respectively:

2.2. Surface Characterization, Vertical Discretization, and Model Input Requirements — ctsm release-clm5.0 documentation

2.26. Crops and Irrigation — ctsm release-clm5.0 documentation

 

[gustavocretton]

Thank you for the information, Keith! I would like to know if is there some tool to do it or how can i change those values. My scenarios are in geotiff format and I can transform it to netcdf file as well. Thanks!

 

[oleson]

The surface dataset is a netcdf file. Easiest way is to use, for example, python or ncl, to change the fields on the surface dataset netcdf file that corresponds to the resolution you are running with.
There is a surface dataset creation tool that will take high resolution surface information and create a surface dataset at your desired resolution, but that has a fairly steep learning curve. You would have to provide the high resolution surface information, e.g, the global distribution of PFTS. It is described here:

1.3. Using CLM tools — ctsm release-clm5.0 documentation

If you are planning to run single point or regional simulations, there are new tools being developed to make that easier, but I don't think they are quite ready yet. See tools/site_and_regional in the latest development code.