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low soil temperature when running a single point clm5.0

Mesmer

Nsassila
New Member
hi every one, my question is this:

that is possible to set a soil temperature when im running a single point in clm5.0 ?? because in all the cases i performed , the soil temperature of clm is always lower than the measurement one . what are the internal variables that i can manage to control TSOIl?
 

oleson

Keith Oleson
CSEG and Liaisons
Staff member
The equations for soil (and snow) temperatures are described here in the CLM5 Technical Note:


Soil temperature will be a function of the amount of heat flux into the surface layer and the thermal (and hydraulic) properties of the soil layers. Properties are a function of soil texture (sand/silt/clay) and soil organic matter. Soil texture and soil organic matter are specified on the surface dataset (PCT_SAND, PCT_CLAY, ORGANIC).
The amount of heat flux into the surface layer can be a function of soil albedo for example. Soil albedo is in part controlled by soil color, also on the surface dataset (SOIL_COLOR).
Snow cover can have an important effect on soil temperature, e.g, a thin snow cover in winter could result in cold soil temperatures because of the lack of insulation provided by the snow.
 

Mesmer

Nsassila
New Member
thank you very much , it is working. please you know if there is a way to give the aspect of the surface in clm ?? or, where i can get the aspect of my surface if it is generated by the model?
 

oleson

Keith Oleson
CSEG and Liaisons
Staff member
I assume you mean south-facing, north-facing, etc. There is no consideration of aspect in CLM.
 

Mesmer

Nsassila
New Member
yes i mean that, but it is not possible to know where my surface is facing nord ,sud o,west or east in clm?or there is noway.
 

oleson

Keith Oleson
CSEG and Liaisons
Staff member
Well, I learn something new about the model every day....
There is a "SLOPE" variable on the surface dataset. However, that appears to be used only for hydrology, in particular for surface water:


and for lateral drainage, e.g.,


This doesn't affect radiation however.

There is a "hillslope hydrology" parameterization that has been under development for a while which I believe includes aspect and slope in radiation calculations but it is not yet available as part of the CLM/CTSM release.
 
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