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CLM soil temperature and soil moisture

S

Sijia Chen

Member
Hello, I also have a question. In the sourcemod, I find two documents defining the soil moisture and temperature . I don't know what this means


1750301446936.png,1750301519167.png
jinmuluo said:
Hi,

To my understanding, both soil temperature and moisture are internally resolved in the CLM. There is a temperature in the CLM forcing input that is "temperature at the lowest atm level," but not the surface soil temperature.
Click to expand...
 
O

oleson

Keith Oleson
CSEG and Liaisons
Staff member
As noted in the subroutine name, InitCold, those are for initialization of the model for a "cold start", when initialization is not provided by an finidat file. After that, soil temperature and moisture are prognostic.
 
S

Sijia Chen

Member
oleson said:
As noted in the subroutine name, InitCold, those are for initialization of the model for a "cold start", when initialization is not provided by an finidat file. After that, soil temperature and moisture are prognostic.
Click to expand...
Ok. I finally understand. Thank you very much
 
S

Sijia Chen

Member
oleson said:
As noted in the subroutine name, InitCold, those are for initialization of the model for a "cold start", when initialization is not provided by an finidat file. After that, soil temperature and moisture are prognostic.
Click to expand...
Hey，dear oleson
if I run spin-up enough years and I run formal simulation. Does that means I can't change the initial soil temperature and moisture because they are not input data in the model and there are no initial values of them
 
slevis

slevis

Moderator
Staff member
The model changes soil temp and moisture during the simulation. This does not mean that you cannot change the initial values somehow.
 
S

Sijia Chen

Member
slevis said:
The model changes soil temp and moisture during the simulation. This does not mean that you cannot change the initial values somehow.
Click to expand...
yes ， I can change the initial values in the cold start. But after that, can I change it. What I mean is in the formal similation, how to change it. And I don't find soil temperature and moisture in the ＂r" document.
 
slevis

slevis

Moderator
Staff member
The default code does not allow you to change soil temp and moisture partway into a simulation; however, you are free to modify the code to do your research.

I am not aware of a " r" document, sorry.
 
S

Sijia Chen

Member
slevis said:
The default code does not allow you to change soil temp and moisture partway into a simulation; however, you are free to modify the code to do your research.

I am not aware of a " r" document, sorry.
Click to expand...
The 'r' document means the restart file after spin-up like this 'CMFDV2100_new1.clm2.r.2090-01-01-00000.nc'. I’m so sorry but I want to know if this means in the formal simulation, I can change the soil temp and moisture. But I don't find soil temp and moisture in the restart file.
 
J

jinmuluo

Jinmu Luo
Member
Sijia Chen said:
The 'r' document means the restart file after spin-up like this 'CMFDV2100_new1.clm2.r.2090-01-01-00000.nc'. I’m so sorry but I want to know if this means in the formal simulation, I can change the soil temp and moisture. But I don't find soil temp and moisture in the restart file.
Click to expand...
Hi,

If you want to reduce or increase the soil moisture in the initial file, you can reference our talks below.

bb.cgd.ucar.edu

How to start with lower soil moisture

Hi, I'm using the compset "I2000Clm51BgcCrop" and I'm wondering where I can change the initial condition for the soil moisture (etc reduce the water to half). Best, Jinmu Luo
bb.cgd.ucar.edu bb.cgd.ucar.edu

But in my personal experiences, the soil moisture is adapted to precipitation very quickly within days, see my graph below, best.

1750788181690.png
 
S

Sijia Chen

Member
jinmuluo said:
Hi,

If you want to reduce or increase the soil moisture in the initial file, you can reference our talks below.

bb.cgd.ucar.edu

How to start with lower soil moisture

Hi, I'm using the compset "I2000Clm51BgcCrop" and I'm wondering where I can change the initial condition for the soil moisture (etc reduce the water to half). Best, Jinmu Luo
bb.cgd.ucar.edu bb.cgd.ucar.edu

But in my personal experiences, the soil moisture is adapted to precipitation very quickly within days, see my graph below, best.

View attachment 6868
Click to expand...
Hi, thank you very much. It looks like changing it has little effect. May I ask what adjustments I can make if the simulation results of my soil moisture are not very good
 
J

jinmuluo

Jinmu Luo
Member
Sijia Chen said:
Hi, thank you very much. It looks like changing it has little effect. May I ask what adjustments I can make if the simulation results of my soil moisture are not very good
Click to expand...
Hi,

I guess you should be able to adjust the soil moisture simulation if you can take a look at the hydraulic parameters in CLM. There are some scale factors in CLM for adjusting the soil hydraulic properties.


src/biogeophys/SoilStateInitTimeConstMod.F90

real(r8) :: bsw_sf ! Scale factor for bsw (unitless)
real(r8) :: hksat_sf ! Scale factor for hksat (unitless)
real(r8) :: sucsat_sf ! Scale factor for sucsat (unitless)
real(r8) :: watsat_sf ! Scale factor for watsat (unitless)

For more information on the above parameters used in hydroloy simulation, pls refer here.

 
S

Sijia Chen

Member
jinmuluo said:
Hi,

I guess you should be able to adjust the soil moisture simulation if you can take a look at the hydraulic parameters in CLM. There are some scale factors in CLM for adjusting the soil hydraulic properties.


src/biogeophys/SoilStateInitTimeConstMod.F90

real(r8) :: bsw_sf ! Scale factor for bsw (unitless)
real(r8) :: hksat_sf ! Scale factor for hksat (unitless)
real(r8) :: sucsat_sf ! Scale factor for sucsat (unitless)
real(r8) :: watsat_sf ! Scale factor for watsat (unitless)

For more information on the above parameters used in hydroloy simulation, pls refer here.

Click to expand...
OK，thank you very much. I'll do it
 
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