4xCO2 configuration

[rml599gh]

A 4xCO2 configuration would be useful for testing ESM1.6.
I had assumed this was just a one line change in atmosphere/namelists (line 652), CO2_MMR= [in kg/kg]
However there is also co2_init= [in ppm] in input_atm.nml

How do these two numbers interact?
[To convert between kg/kg and ppm, multiply by 659090.91]

[MartinDix]

Looking at the code suggests the value from input_atm.nml is not used. Checking the setup for Tilo's runs showed they all used co2_init=284.725, no matter the scenario.

If it's really not used it should be removed to reduce confusion (and probably from ESM1.5 as well).

I'll set up a test.

[MartinDix]

New dev configuration https://github.com/ACCESS-NRI/access-esm1.6-configs/tree/dev-4xCO2%2Bconcentrations

One year test run compared to ESM1.5 CMIP6

[JhanSrbinovsky]

doesnt the fact that they are not identical suggest that it is used?

[MartinDix]

The ESM1.5 run was on raijin so it's not possible to reproduce it.

[access-hive-bot]

This issue has been mentioned on ACCESS Hive Community Forum. There might be relevant details there:

https://forum.access-hive.org.au/t/esm1-6-land-meeting-notes/3831/6

[MartinDix]

Needs to be updated for generic tracers, #4