The AODVIS field from the CESM LME data set has very small perturbations, or at least much smaller than the corresponding fields that I get form my own CESM2 simulations. It is also worth noting that the perturbations of the CESM LME AODVIS is in the negative direction, while in CESM2 all AOD values and perturbations from equilibrium is to positive values.
Let us first have a look at the fields that can be found in CESM2 that says something about aerosol optical depth. This include:
| Legend | Short Name | Long name |
|---|---|---|
| AOD(d) | AODVIS | Aerosol optical depth 550 nm, day only |
| AOD(dn) | AODVISdn | Aerosol optical depth 550 nm, day night |
| SAOD(nd) | AODVISstdn | Stratospheric aerosol optical depth 550 nm, day night |
We also include for reference the difference between AOD(dn) and SAOD(dn).
Figure: Different CESM2 AOD fields
Let us then focus more on the difference time series, namely AOD(dn)-SAOD(dn), and
compare this to the AOD field that is found in the CESM LME data set. This also include
a shifted version, where the biggest eruption (1258) has been placed in 1852. This
eruption has an estimated injected SO2 of 258 Tg, while the CESM2 simulation we
compare with now uses an injected SO2 of 400 Tg.
| Legend | Short Name | Long name |
|---|---|---|
| CL AOD | AODVIS | Aerosol optical depth 550 nm |
| CL AOD 1258 | AODVIS | Aerosol optical depth 550 nm, shifted version |
Figure: CESM LME original and shifted compared to the difference time series. Also included for reference is the AOD(dn) time series
To better see the prominence of the 1258 eruption and where it was shifted to, below is a plot of the full CESM LME AOD time series with both the original and shifted version.
Figure: CESM LME original and shifted version