equilibrium state setting

[tenghao]

Hello, everyone:

I am now using CLM5.0.35 for simulation. The research area is permafrost region, with a resolution of 0.1 degrees. I mainly pay attention to the output variables of soil hydrothermal conditions and carbon and nitrogen cycles in permafrost regions. Now facing the following problems:

(1) Due to the limited computing resources, there are about 15,000 surfdata grids in the research area, and it takes a long time to reach the equilibrium state. I can first create a surfdata grid with a resolution of 0.2 degrees, run this case to reach the equilibrium state, and get a 0.2.r.nc file. After that, I will create a formal simulation case of 0.1 degree, set finidata to 0.2.r.nc, set use_init_interp=.true in user_nl_clm, run it for another 10-50 years, and then start the formal simulation. Is that ok?
(2) My atmospheric forcing data is prepared by CMFD data with a resolution of 0.1 degrees. Can it drive the case with a resolution of 0.2 degrees to run normally? Do I need to set any parameters?
(3) If I change some parameters of soil hydrothermal characteristics (such as soil thermal conductivity, porosity, etc.), do I need to re-run the model to reach the equilibrium state when simulating in the changed case? If necessary, can my R file be designated as 0.2.r.nc in the case of 0.2 degree resolution?

Good luck​

 

[oleson]

1. From a functional point of view, this should work.
2. This should work. The datm should be able to interpolate from 0.1 to 0.2
3. I would advise a separate spinup if you are changing soil hydrothermal characteristics.

 

[tenghao]

Thank you for your reply:

1. From a functional point of view, this should work.

Although CLM may run normally, is this approach appropriate for permafrost research? Compared to running the simulation directly to equilibrium at a 0.1-degree resolution, how does this affect the results? The primary focus is on variables related to soil water and heat conditions and the carbon and nitrogen cycles.