NAN soil carbon in accelerated decomposition spinup

[jiamengl]

Hello,

I changed the CLM code for soil decomposition part so I want to re-spin-up the case. I tried to follow the instruction in 1.5.5. Spinup of CLM5.0-BGC-Crop — ctsm release-clm5.0 documentation but I met issues in accelerated decomposition step.

Seems like once using the AD scenario, the simulated soil carbon will all be nan values across the entire simulation period (200 years). And is using the restart file generated from the AD scenario, the following simulation also gives nan values for soil carbon. I tried to run without 'accelerated decomposition' and this gives reasonable results.

I don't have background knowledge about the accelerated decomposition, but in the user guide, the figures showing the result from AD spinup did have reasonable values for TOTSOMC, so I am wondering what caused the nan values in my run, and should I give up AD spinup and just normally spinup for hundreds of years?

Thanks!

 

[nusbaume]

Hi Jiameng Lai,

I am moving this post to the CLM forum, as they are the ones who can most likely answer your question.

Hope that helps, and have a great day!

Jesse

 

[oleson]

I think I would pursue solving the AD issue as it will shorten up your spinup time considerably and might be an indication of other problems in your code. To start, you could look at if statements containing "spinup_state", which is a namelist variable, in the code, which is what triggers AD mode. A general description of AD can be found here:

2.21. Decomposition — ctsm CTSM master documentation

escomp.github.io

 

[jiamengl]

I think I would pursue solving the AD issue as it will shorten up your spinup time considerably and might be an indication of other problems in your code. To start, you could look at if statements containing "spinup_state", which is a namelist variable, in the code, which is what triggers AD mode. A general description of AD can be found here:

2.21. Decomposition — ctsm CTSM master documentation

escomp.github.io

Thanks so much for your suggestion! Indeed I found my code contain 'spinup_state' and this should be the reason for my issue.