How/where is CAM calculating carbon fluxes from CLM into concentration (ppm)?

[maria_kvalevag@cicero_uio_no]

The prognostic co2 - version of CAm is not supported but I still have a question I hope you can help me with. When using this version of the coupled CLM/CAM (co2_flag = .true.) the calculated co2 (the CO2 variable in the history-files) in CAM is too high compared to observations. This is because NEE from CLM is too high in my runs, but I want to investigate this further..

in atm_comp_mct the total co2 flux from ocn, fff and lnd is set:
! merged co2 flux
cam_in(c)%cflx(i,c_i(4)) = cam_in(c)%cflx(i,c_i(1)) + &
cam_in(c)%cflx(i,c_i(2)) + &
cam_in(c)%cflx(i,c_i(3))

but where and when is cam_in(c)cflx(i,c_i(4)) incorporated in the equation that calculates the atmospheri cco2-concentration (in ppm)??

 

[eaton]

The fluxes for all constituents are stored in the cam_in%cflx array. These
fluxes are added to the bottom layer of the atmosphere by the vertical diffusion
module. cflx is an argument to the compute_vdiff call. In subroutine compute_vdiff
(module diffusion_solver) at about line 732 you'll see where cflx is added to the
lowest atm layer. The units here are mixing ratio (kg/kg).