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How to use the variable ‘cSoilLevels’

Wenzhe Guo

Wenzhe Guo
New Member
Dear all
Happy New Year!
I don’t understand how to use the variable ‘cSoilLevels’(Carbon Mass in Each Model Soil Level) in CESM2. I don't know what the data of carbon mass given in each level means (Data Information View (dkrz.de)). For example, if I want to get the total carbon storage in the soil layer above 0.26m, how should I calculate it?
Thanks in advance!
 

oleson

Keith Oleson
CSEG and Liaisons
Staff member
Sorry for the delay on my response. I didn't get notified because your message seems to be marked as possible spam.
There should be a depth variable associated with this, "depth" that can be used to get total carbon storage above 0.26m.
 

Wenzhe Guo

Wenzhe Guo
New Member
Sorry for the delay on my response. I didn't get notified because your message seems to be marked as possible spam.
There should be a depth variable associated with this, "depth" that can be used to get total carbon storage above 0.26m.
Thank you for your help! I have noticed the variable "depth" before posting my question. I know that the variable ”cSoilLevels”(kg/㎡) reports total soil carbon for each level. However, I found that the value of the variable ”cSoilLevels” is gradually declined from 0.01m to 8.03m (depth range). The value of the variable ”cSoilLevels” for 0.26m “depth” isn’t total carbon storage above 0.26m. How should I calculate? Is there something wrong?
Looking forward to your reply!
Best Regards.
 

Wenzhe Guo

Wenzhe Guo
New Member
Right, it's the carbon storage for the layer that has a node depth of 0.26m.
The soil layer structure can be found in the CLM5 technical note:


If you wanted soil carbon storage above 0.26m, then I guess you could take a weighted average of the layers.
Thank you! Your advice is very helpful to me.
I have another question for you. Does 'cSoilLevels' refer to soil organic carbon or total soil carbon? Does the model contain predictions for future soil organic carbon?
Best Regards.
 

oleson

Keith Oleson
CSEG and Liaisons
Staff member
This is the definition of cSoilLevels in CMIP6:
Carbon mass in each model soil level (summed over all soil carbon pools in that level): for models with vertically discretised soil carbon, report total soil carbon for each level cell_methods:area: mean where land time: mean cell_measures:area: areacella positive:

CLM5 also has prescribed soil organic carbon which is thermally and hydrologically active but doesn't interact with the carbon cycle:


"The soil texture and organic matter content determine soil thermal and hydrologic properties (sections 6.3 and 7.4.1). The International Geosphere-Biosphere Programme (IGBP) soil dataset (Global Soil Data Task 2000) of 4931 soil mapping units and their sand and clay content for each soil layer were used to create a mineral soil texture dataset (Bonan et al. 2002b). Soil organic matter data is merged from two sources. The majority of the globe is from ISRIC-WISE (Batjes, 2006). The high latitudes come from the 0.25o version of the Northern Circumpolar Soil Carbon Database (Hugelius et al. 2012). Both datasets report carbon down to 1m depth. Carbon is partitioned across the top seven CLM4 layers (
\sim
1m depth) as in Lawrence and Slater (2008)."
 
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