Zero GPP after running the crop module with clm6

[ruparati.chakraborti@list]

I am running clm6 with the Compset "I1PtClm60Bgc'' for crop 'rice' .Using one year forcing data, I am getting the below plots (presented for some of the variables). My concern is here, we are getting GPP/CPOOL as 'zero'. What could be the possible reason?


Secondly, when I am trying to spinup the model with the below changes in the xml file
./xmlchange CLM_ACCELERATED_SPINUP="on"
./xmlchange RESUBMIT=3,STOP_N=50,STOP_OPTION=nyears
After spinning up, I am getting the trend plot using the annual mean values of the below variables from the history files.


My question is what could possibly go wrong to get the 'zero' GPP values?

 

[oleson]

So the I1PtClm60Bgc compset does not have crops on. The longname for that compset (at least in ctsm5.3.0) is

2000_DATM%1PT_CLM60%BGC_SICE_SOCN_SROF_SGLC_SWAV

For crops to be active it would need to be

2000_DATM%1PT_CLM60%BGC-CROP_SICE_SOCN_SROF_SGLC_SWAV

You can confirm whether the crop model is active in your case by looking for "use_crops" in your lnd_in.

If crops aren't active, then I think that even if you've specified a crop type (e.g., rice) in your surface dataset, the model will collapse that to the generic crop type.
Also, I see in one of your previous posts, you've used this command:

./subset_data point --lat 50.86 --lon 6.44 --site 1x1_testcrop --create-surface --surf-year 2000 --create-user-mods --create-datm --datm-syr 1917 --datm-eyr 1918 --create-domain --dompft 50 --crop --inputdata-dir /ec/res4/scratch/lums/cesm/inputdata --overwrite

But dompft 50 is an inactive crop (irrigated groundnuts). I'm not sure what happens if you select that, but rice is either 61 (rainfed) or 62 (irrigated). But maybe you've fixed this already...

 

[ruparati.chakraborti@list]

Thank you so much for the detailed explanation!

 

[ruparati.chakraborti@list]

Hi,
After updating the compset and surface data as previously suggested, I was able to run the model with the crop module activated for rainfed rice (dominant PFT = 61, use_crop = .true. set in lnd_in). However, the output still shows zero values for GPP. I’ve attached plots for GPP, NPP, canopy transpiration (QVEGT, which has very low values), and GrainC. I would appreciate your guidance on what might be causing GPP to remain at zero.


Additionally, I would like to clarify that my intention is to use the planting date, harvest date, and other crop phenology-related parameters from the crop parameter file. I’ve attached a snapshot of my user_nl_clm settings to reflect this configuration. Please let me know if these settings are correct or if any adjustments are needed.

 

[slevis]

Have you run longer than one year? If not, I think you should try running at least one more year in case this is just the crop model needing more than one year of accumulation variables to grow crops.

 

[ruparati.chakraborti@list]

Hi,
Yes, I have run the model for 10 years starting from 2006 till 2015 (as the plots for different years are attached). The result is same for GPP (zero for all the years)

 

[slevis]

...but GRAINC has non-zero values despite GPP = 0? If so, then the problem may be diagnostic somehow.

 

[ruparati.chakraborti@list]

Hi, the issue is sorted now. I am getting GPP now after changing the setting in user_nl_clm ; hist_avgflag_pertape = 'A'. ( Earlier, it was hist_avgflag_pertape = 'I').
Thanks,