Hi all, I’ve got a query about the mixed layer diagnostic in ACCESS-CM2. The model output I’m using (pre-industrial configuration) shows very deep mixed layers in the Ross Sea (left panel below).
I’ve recalculated the MLD using a 0.03 g/kg density criterion (blue dashed line in figure above, middle map panel) and it produces vastly different estimates than the model mld diagnostic (solid blue line in figure above). The recalculated mixed layer depth looks correct to me. Is this a known issue? Is the model mld diagnostic incorrect, or is the monthly averaging of T and S hiding deep convection events that occur on shorter timescales?
We’re not yet sure whether this indicates an issue with the ACCESS-CM2 mld diagnostic or is related to differences in how the diagnostic is calculated/averaged.
Thanks @RhaegarZeng. I’ve checked out Katja’s notebook and the way I’ve calculated the mld above is essentially the same, minus the last interpolation step. Would your recommendation at this stage be to use a manually calculated MLD, rather than the model diagnostic?
Thanks @hrsdawson . I’m probably not the right person to make a recommendation on which MLD diagnostic you should use, as this is outside my area of expertise.
Given that your calculation is essentially consistent with Katja’s approach, you could certainly try using that method for your analysis. Otherwise, it may be worth waiting to see if someone in the community with more expertise in MOM5/MLD diagnostics can provide a more definitive answer on the model diagnostic.
