To include time varying solar constant

[rohi@caos_iisc_ernet_in]

Dear all,

I am using CAM 4 to make a future climate simulation with time varying solar constant and CO2. However i am not able to figure out how to give linear variation in solar constant which is by default a constant value in the default name list file.

Could anyone help me resolve this issue.

Thanks in advance

Rohi

 

[eaton]

The default namelist settings are for present day climatological conditions.  To see how the namelist is set up for a historical period try running build-namelist with the argument "-use_case 1850-2005_cam4".  This will produce a namelist that uses a dataset in which the total solar irradiance varies in time.  Similarly for the other boundary datasets. 

 

[rohi@caos_iisc_ernet_in]

Dear Eaton,Thanks for the reply but i am not looking for a default time varying solar constant file instead i want to give my own linear variation to solar constant which is just a number by default.Is it possible using E1850CN component set to create a linear varying solar constant for a future scenario.

 

[eaton]

Look at the default time varying file and how it is used.  Then create your own time varying file and customize the namelist to make use of it.  If you are interested in using time varying data for future scenarios then starting from a compset designed for a fixed climatological year (like E1850CN) is not a good place to start.  Start from a compset that is designed for one of the RPC future scenarios and modify that with your custom boundary datasets.

 

[zwang19@masonlive_gmu_edu]

Hi Eaton,

May I know how to "try running build-namelist with the argument '-use_case 1850-2005_cam4'"?
To which executable file is the option "-use_case" available?
I tried to search for a file named build-namelist but couldn't find it.

Thank you.

 

[eaton]

build-namelist is a perl script used to construct the namelist file for CAM, and other componets as well if invoking it from a CAM standalone script.  It is called directly from a CAM standalone script. It is invoked by the cam.buildnml.csh script when running from CESM scripts.  Basic use of build-namelist along with a description of its options is given in the CAM User Guide available from the CAM home page.