Add AerChemMIP scenario entries

[znichollscr]

• Add ScenarioMIP experiments #84

[znichollscr]

Not sure who to ask about this

[znichollscr]

@bethdingley only question is here. I couldn't figure out what hist-piAQ was meant to be...

[bethdingley]

From the AerChemMIP paper:
hist-piAQ, where anthropogenic SLCF emissions contributing to air pollution are set at PI levels [...] The experiment hist-piAQ is the same as hist-piNTCF from AerChemMIP phase one (Collins et al., 2017) except the new name accurately reflects the experimental protocol wherein air pollutant emissions, including non-CH4 tropospheric O3 precursors, aerosols and their precursor emissions (BC, OC, NH3 and SO2) are set to PI levels. The experiment hist-piAQ can be used to diagnose the climate and air quality responses to the regionally heterogeneous evolution of anthropogenic nonCH4 SLCF emissions. [...] Models which can simulate SLCFs other than aerosols (i.e., CHEM) should perform hist-piAQ while models without such capability (i.e., AER) are asked to perform hist-piAer.

Does this answer your questions? If not, we can tag AerChemMIP for more details

[znicholls]

Does this answer your questions?

Not really. What I'm trying to figure out is whether these are meant to have prescribed SSTs or not (this hist-pi* naming is unique in Dunne et al so hard to know whether it's its own thing or a typo).

@fmoconnor do you know anything about these hist-piAQ and hist-piAer experiments? Are they like the piClim* experiments with prescribed SSTs or like the DAMIP experiments (i.e. freely evolving SSTs)?

[znicholls]

Also, Dunne et al (https://gmd.copernicus.org/articles/18/6671/2025/gmd-18-6671-2025.pdf) Table 3 suggests that 6 ensemble members are required. Is that correct?

[znichollscr]

Marking as ready to allow @ltroussellier to merge (as WCRP-CMIP/CMIP7-CVs#319 was merged, we need to merge this to test. I'll come back to both once there are more answers above)