CCSM_CCOST question

[ccsmwrf@gmail_com]

To whom it may concern:

I found a few setting related to CCSM_CCOST.
a)
CCSM_CCOST="3"
CCSM_CO2_PPMV="0.000001"
b)
CCSM_CCOST="0"
CCSM_CO2_PPMV="368.9"

Could anyone explain what different CCSM_CCOST values mean? Also, why CO2 concentrations have so much differences? I have found someone use negative CCSM_CCOST, but not sure what it means.

Thanks

Yang

 

[eaton]

The User's Guide says CCSM_CCOST is somehow related to the cost of running the compset. It's a measure relative to the cost of running the B compset. The description is pretty vague.

CCSM_CO2_PPMV is only used to set the CO2 value in cases where it is a fixed value. In some compsets the value is ignored because the CO2 values are read from a file. In other cases (like most of the ones where it is set to 1e-6) the value is ignored because CO2 is a prognostic variable.

 

[ccsmwrf@gmail_com]

Thanks for your message, eaton. It seems to me it does not matter too much about the values of CCSM_CCOST.