Constant volcanic forcing

[OrHess]

Hello,

I'm running CESM1.1.2 under the historical experiment "b.e11.B20TRC5CNBDRD.f09_g16.001" with constant volcanic forcing. I added the following lines to user_nl_cam:

prescribed_volcaero_datapath = 'THE VOLCAERO FILE PATH'
prescribed_volcaero_file = 'CCSM4_volcanic_1850-2008_prototype1.nc'
prescribed_volcaero_fixed_ymd = 19911015
prescribed_volcaero_type = 'FIXED'

By examining the output variable 'FSNSC' (clear-sky net solar flux at the surface) compared to a regular simulation (where volcanic forcing isn't fixed), it appears my simulation is working, as the surface solar flux values are significantly lower. However, I have a few questions:

1. Fixed Values: How can I determine the specific values in the constant forcing simulation? Is there a way to know what the fixed values are? For instance, using '19911001' as the fixed date yields different results, even though the variables in 'CCSM4_volcanic_1850-2008_prototype1.nc' are in monthly timesteps.
2. Output Variables: Are there better output variables than 'FSNSC' to verify if my constant volcanic simulation worked? The current variable I use also reflects changes in albedo and solar flux. I am looking for a variable that isolates the impact of volcanic forcing changes.
3. CESM2 Simulation: To perform a similar simulation using CESM2, is it sufficient to modify user_nl_cam? What specific lines should I add this time?

Thank you for your assistance!

 

[peverley]

Apologies for the delay.

Moving this to the CAM-chem forum in the hopes that they can answer your question.