Fossil Fuel Change BSSP126 and no difference in TS

[jbuzan@purdue_edu]

Hi CESM users:
I have changed the fossil fuels emissions file, and ran my compset: BSSP126 simulation and get the same temperature. This is the difference between a case with minor emissions mitigation and strong mitigation. Year Five is a 6 PgC annual difference in C emissions, resulting in a 6ppm change in atmospheric CO2. However, the surface temperature remains the same. I checked the drv_in file:
drv_in: flds_co2c = .true.

Which CO2 is evolving. I am just surprised that there are no temperature differences (even spatially). I am surprised by this result. Is there a flag I missed in the setup?

Below are globally summed/averaged values:

CO2_total = 0.203277587890625, 0.87481689453125, 2.11798095703125, 4.00076293945312, 6.5538330078125 ; ppmv
C_flux_total = 0.856830775682226, 1.97485278394375, 3.27536054660687, 4.67964858549386, 6.109011422427 ; PgC/yr
TS_total = 0, 0, 0, 0, 0 ; K

Cheers,
-Jonathan

 

[cacraig]

I am moving this to the CAM-Chem forum as they can help you with emission files.

 

[jbuzan@purdue_edu]

Hi Cheryl Craig,

Thanks for moving the thread.
::update::
I am now 8 years into both simulations, and they both have the same Surface Temperature. These simulations should have at least diverged by now with such large differences in emissions.

 

[jbuzan@purdue_edu]

::Update::
I took the difference in the env_run.xml between my BSSP126 (left) and BHIST_BPRP (right) runs, and these flags jumped out at me.
< <entry id="CAM_NAMELIST_OPTS" value=" co2_cycle_rad_passive=.true. "> --- <entry id="CAM_NAMELIST_OPTS">

< <entry id="CLM_CO2_TYPE" value="diagnostic"> --- <entry id="CLM_CO2_TYPE" value="prognostic">

< <entry id="OCN_CO2_TYPE" value="diagnostic"> --- <entry id="OCN_CO2_TYPE" value="prognostic">

 

[Dahuzi]

Hi CESM users:
I have changed the fossil fuels emissions file, and ran my compset: BSSP126 simulation and get the same temperature. This is the difference between a case with minor emissions mitigation and strong mitigation. Year Five is a 6 PgC annual difference in C emissions, resulting in a 6ppm change in atmospheric CO2. However, the surface temperature remains the same. I checked the drv_in file:
drv_in: flds_co2c = .true.

Which CO2 is evolving. I am just surprised that there are no temperature differences (even spatially). I am surprised by this result. Is there a flag I missed in the setup?

Below are globally summed/averaged values:

CO2_total = 0.203277587890625, 0.87481689453125, 2.11798095703125, 4.00076293945312, 6.5538330078125 ; ppmv
C_flux_total = 0.856830775682226, 1.97485278394375, 3.27536054660687, 4.67964858549386, 6.109011422427 ; PgC/yr
TS_total = 0, 0, 0, 0, 0 ; K

Cheers,
-Jonathan

Hi Jonathan,
I also encountered the same problem while running BSSP126 using CESM2.1.3. The default settings in CESM2 uses CO2 concentration from flbc files to impact climate. Have you solved how to modify settings to use CO2 concentration from co2flux_fuel to affect the climate?

Many thanks!

Cheers,