about REST_OPTION

[jhuang]

Hello, everyone
I am a newcomer of CESM. My CESM version is 1.2.2. I have some questions about the RUN_STARTDATE of the CESM：
（1)When I use some composet such as B_2000, the 2000 means the initial data is 2000-01-01? If I change RUN_STARTDATE to 2010-01-01, it still uses initial data of 2010-01-01? If so, the results are not changed though I have changed the RUN_STARTDATE?
(2) When I use the other composet such as B_1850-2000, the 1850-2000 means the initial data is 1850-01-01? The model works when I set RUN_STARTDATE to 1920-01-01. However, if I set RUN_STARTDATE to 1950-01-01, the model doesn't work, what is the reason? The error displays "CFCs cannot be automatically initializd post 1930 in a startup run! Set init_cfc_option in user_nl_pop2 before building pop2_in."
(3)What is the difference between B_2000 and B_1850-2000? just for different initial time?
Thank you!

 

[mlevy]

To answer your second question: CFCs are configured in POP to be 0 prior to 1930 and then they get added to the ocean model via external forcing. As the error message says, these tracers can not be automatically initialized after that year -- you need to specify exactly what to initialize the CFC11 and CFC12 tracers to. (And then you'll probably get similar errors from the sf6 tracer module.)

I want to leave this thread in the infrastructure forum because of your question about the two compsets, but if you want more information about the CFC tracers, please post in the POP forum

 

[jedwards]

As a new user you should not be using cesm1.2.2, it is no longer a supported model version. Please consider using
cesm2.1.x or newer.

For hybrid startups (those using a REFCASE) the RUN_STARTDATE must match a date for which initial data is available.