Change yield of production of secondary organic aerosols from isoprene

[oyvindseland]

What is the feature/what would you like to discuss?

The yield of isprene to SOA should be reduced from 5 % to 0.5 % Impact all chemistry set-up (chem_mech.doc) Should likely be default in NorESM2.3. Sara Blichner should be asked if she still think the 0.5 % is what she recommends. Added her github in the discussion section below

Is there anyone in particular you want to be part of this conversation?

@sarambl

Will this change (regression test) answers?

Yes

Will you be implementing this enhancement yourself?

Yes, but I will need some help

[gold2718]

Completed by #176

[DirkOlivie]

Hi Sara @sarambl (@oyvindseland @gold2718),

we have now reduced the SOA-yield for isoprene from 0.05 to 0.005 in NorESM2.3. We see however that the anthropogenic aerosol ERF becomes considerably stronger: -1.62 W/m2 (+/-0.08 W/m2). In earlier versions (NorESM2), the anthropogenic aerosol ERF was around -1.2 to -1.4 W/m2.

Have you tested the anthropogenic aerosol ERF with these lower SOA-yields? Did you get similar results?

Might the impact of these SOA-yield changes also be different in a simulation containing your NPF code and a simulation without the NPF code (NorESM2.3 currently doesn't contain the NPF code)?

Best regards,
Dirk