Soil moisture in mm (millimeter)!!!

[sukanta1003@gmail_com]

I am a CCSM3.0 user, focusing on the land part (CLM) of the model. I am trying to compare the soil moisture (SOILLIQ + SOILICE) from CLM with CPC soil moisture climatology. The problem is that,
the model derived soil moisture has unit 'Kg/m^2' whereas the CPC soil moisture has the unit 'mm'.

My question is "how to convert 'Kg/m^2' (water weight) to 'mm' (water height equivalents)?
If you have any idea, kindly help me.
Thank you.

 

[slevis]

This calculation should be trivial for any scientist. Having said that, I'm not sure whether I would have considered it so intuitive, had I not solved it for a homework problem early on in graduate school...

1 Kg water per m^2 soil is equivalent to 1 liter water per m^2 soil =
10^-3 m^3 water per m^2 soil =
10^-3 m water =
1 mm water

Sam Levis

 

[rrachmayani@marum_de]

Dear Sam,

I am wondering how to use 4 PFTs (less PFTs) instead of 10 PFTs in CLM-DGVM? Should I change the PFTs initial value? Thank you.

Best,
Rima

 

[slevis]

Not sure I understand the question.

Do you mean that you would like to eliminate, for example, grasses from the simulation and run only with trees? If so, go to the table in the code that defines the bioclimatic limits of each pft and set the bioclimatic limits out of bounds for the pfts that you don't want (examples of that already exist for some pfts that had to be excluded).

Or do you mean that you want each gridcell to allow up to 4 pfts coexisting instead of up to 10? If so, you'll need to change a parameter called maxpatch_pft (I think that's the name), and you can do that in the code, though you may be able to do it in the clm jobscript. If you try the jobscript option, you may find that your change is ignored because we may have hardwired 10 as the only acceptable value for the dgvm. I believe that the dgvm won't work correctly for long with a value of 4 because sometimes more than 4 pfts want to coexist in a gridcell.

If I misunderstood the question, then pls be more specific.

Sam