Questions about B_RCP8.5_CAM5_CN run, should I spin-up?

[mlevy]

Hello, I am also curious about your first question. If I want to run from 2005-2020, should I set the RUN_STARTDATE=2005-01-01 OR RUN_STARTDATE=2006-01-01？ In other words, if I set the RUN_STARTDATE=2005-01-01, the model's simulation result that I can use is 2005-2020 OR 2006-2020? Thanks for your help!

RUN_STARTDATE tells the model what year to start in, and transient runs will use the model year for forcing data. So setting RUN_STARTDATE=2005-01-01 and running for 16 years will use forcing from January 2005 through December 2020. However, the model state is initialized based on the contents of the rpointer files, so if they point to restart files from a previous run that went through 2005 there will be a small inconsistency because you will be starting with a model state from 2006. I say "small inconsistency" because I would be surprised if there was a big difference between 2005 and 2006 restart files.

Hey, I am interested to know about the run type as you discussed. If I am selecting the compset B_RCP8.5_CAM5_CN and giving the GET Reference case as false and Run type as Startup. Where will the model start? Is the model starts from a Cold Start?

I believe the default initial conditions for most models are spin-up to equilibrium using the pre-industrial forcing, so a reasonable estimate for 1850. You might want to ask this question in the model-specific forums, though: CAM (atmosphere), CLM (land), CICE (sea-ice), POP (ocean)

 

[ohmpawat]

First, if you really want to run CESM 1.2 then I suggest moving to the latest release (which I believe is 1.2.2.1).

Second, to run from 1994 - 2018 you would just break it up into two runs. Run from 1994 - 2005 in a B20TRC5CN and then use a hybrid run with the RCP compset and REFCASE pointing to your first run for the future scenario portion.

I am going to move this to the Community Projects forum, because the big question remaining is "how do you get 1994 restart files to start your first run" and I don't know the answer to that.

Hi, I want to use CAM-CHEM to run from 1995 to 2100 and I know I should break it up into two runs. However, CAM-CHEM related compsets don't have the RCP/SSP compset. So, what should I do to finish my simulation? Thanks in advance.

 

[tgm]

Hi, I want to use CAM-CHEM to run from 1995 to 2100 and I know I should break it up into two runs. However, CAM-CHEM related compsets don't have the RCP/SSP compset. So, what should I do to finish my simulation? Thanks in advance.

Hi, I'm experiencing a similar issue to what you had. Do you find a way to figure out how to run CAM-CHEM in RCP scenarios?