Evaluation: Conservation of water, salt, heat

[chrisb13]

Chatting to @taimoorsohail about this.

I think this script might be a useful starting point @aekiss ? Any others? I think @anton-seaice was thinking about similar budgets a while back?

(@PaulSpence for interest?)

[chrisb13]

How's it going @taimoorsohail? Need any input?

[taimoorsohail]

Hi @chrisb13 - I have been on holiday for the last 2 weeks and just got back! I am working on some grants for the next couple of weeks but hope to get to this in my free moments!

[chrisb13]

Thanks for the update @taimoorsohail; helpful to know it's still on the radar.

Hope the holiday was good!

[taimoorsohail]

Hi @chrisb13, what's the variable for grid cell thickness? It was dzt but I can't seem to find that here... I'm trying to compute ocean volume over time.

[aekiss]

The scope of this issue is unclear to me @chrisb13. Are you wanting checks that the water, salt and heat are correctly passed between components?

We already plot timeseries related to water and salt coupling budgets in https://github.com/ACCESS-Community-Hub/access-om3-paper-1/blob/main/notebooks/timeseries.ipynb

Note that water balance in the ocean+ice system is currently misconfigured ACCESS-NRI/access-om3-configs#920

[taimoorsohail]

I was under the impression that it would be a comparison between integrated wfo and the corresponding salinity change, and ditto for hfds and OHC. This was to ensure the heat and salt budgets close globally; and to compute meridional heat and salt fluxes if globally closed. Correct me if I'm wrong @aekiss and @chrisb13.

[anton-seaice]

what's the variable for grid cell thickness?

Is this the correct one?

"thkcello"  [Used]
    ! modules: {ocean_model,ocean_model_z,ocean_model_rho2,ocean_model_d2,ocean_model_z_d2,ocean_model_rho2_d2}
    ! dimensions: xh, yh, zl
    ! long_name: Cell Thickness
    ! units: m
    ! standard_name: cell_thickness
    ! cell_methods: xh:mean yh:mean zl:sum area:mean
    ! variants: {thkcello,thkcello_xyave}

Should be available on z, rho and native coordinates as a monthly mean

[chrisb13]

Thanks for coming back to this @taimoorsohail.

I think I did mention some of @aekiss prior work on this when discussing this with @taimoorsohail? I wasn't able to find any associated comments (maybe it was in our VC?) but I think the scripts I had in mind were these:

• https://github.com/ACCESS-NRI/access-eval-recipes/blob/main/ocean/runoff_budget.ipynb
• https://github.com/ACCESS-NRI/access-eval-recipes/blob/main/ocean/runoff_conservation.ipynb

At a quick glance, it looks like these scripts are more in line with what @aekiss is suggesting?

I don't think I was the person that suggested this diagnostic but I was naively imagining it to be a global physical check. Does the model lose volume, salt, heat...