Why ATM_CO2 is 0?

[Xiao-Yuan]

Hi, all.

I want to do some sensitivity tests with only ocean modules and MARBL. I set the compset is SSP585_DATM%NYF_SLND_CICE_POP2_DROF%NYF_SGLC_WW3_BGC%BPRP. When I set the 'OCN_CO2_TYPE=prognostic', the 'ATM_CO2' in the output files is 0.

Why does this occur and how to fix it?

Any help will be greatly appreciated! Thanks!

Yuan

 

[klindsay]

BPRP compsets are intended for when you have an active atmospheric model that prognostically advects an atmospheric CO2 tracer/constituent, uses this tracer for radiative computations and passes the tracer values to the land and ocean models for use in their BGC modules. The surface models are using the co2 prog field from the flux coupler in their computations. It looks like datm is not passing the SSP585 CO2 values in the co2 prog field and it is zero. This makes sense, since datm doesn't have a prognostic CO2 tracer to pass. I suggest using BDRD instead of BPRP, and I expect that datm will pass the SSP585 values in the co2 diag field.

More information about BPRP vs BDRD is available in this year's CESM tutorial pages.