Hi everyone. I am an Hons student at UNSW working with Alex Sen Gupta and Matt England. I am constructing a heat budget for some marine heatwave events around Antarctica, using a 0.25 degree ERA-forced experiment (‘025deg_era5_iaf_1958cycle1’).
I have monthly data for sw_heat, and was wondering if anyone knew how this was calculated in the model. It says the penetrative shortwave heat, but I was wondering what the depth this term penetrates to? Is it shortwave heat through the mixed layer calculated by the model?
I also have pme_river at daily intervals. It says “mass flux of precip-evap+river via sbc (liquid, frozen, evaporation)” - I was wondering if captures the mass flux associated with sea ice melt, as it says frozen? I can see that this is it’s own indepenent term in monthly intervals.
My understanding is that pme_river does not include sea-ice melt/freeze. I guess the frozen in that description refers to frozen run-off from icebergs.
Hi @tom_schmaltz. Regarding sw_heat, I think most (all?) of the ACCESS-OM2 experiments use the MOM5 ocean_shortwave_gfdl module with optics_manizza = .true. and read_chl = .true.(you can confirm this by looking at ocean/input.nml for the experiment you are interested in).
This means that shortwave penetration is calculated following Manizza et al. 2005 (doi:10.1029/2004GL020778) using climatological chlorophyll concentrations from the provided input file (called chl.nc).
If you’re interested in looking at the code, this is where sw_heat is calculated based on the fractional sw penetration calculated here.
@tom_schmaltz just wondering if this post was satisfactorily answered for you?
In particular, I wonder if your question about sw_heat is more about what the field actually is? To explain - sw_heat is a 3D depth-dependent field that corresponds to a redistribution of the SW radiation from the surface layer to deep layers. I.e. in sunny regions of the ocean this will have large negative values in the top layer and positive values below. It’s vertical sum is zero. It is constructed this way so that when you add it to the absorbed total SW radiation (e.g. swflx, which is a 2D field and thus considered to be only non-zero in the top layer) you get the total SW absorbed into the ocean as a function of depth.