Adding complex dFe cycling to WOMBAT-lite (#13)

* Introduced computations for dFe precipitation, scavenging and coagulation. These are not yet active within the dFe cycle, but will be made so in the next step. Diagnostics for precipitation, scavenging, ambiguous loss in shallow environments and coagulation are output from the model. These show that scavenging is absolutely minimal while ambiguous loss and coagulation are much larger sinks of dFe, which makes sense given that scavenging only occurs when free Fe is in excess of its solubility. I think...

* Added FeIII precip, FeIII scavenging, dFe loss and coagulation onto detritus to the fe tracer source/sink term. Removed the previous use of scavening and background dFe concentrations.

* phyfe, zoofe, and detfe have all been added as tracers now. They are currently mirroring phy, zoo and det

* variable Fe2C ratios implemented in source and sink terms. Model stable. Also outputting new diagnostics of fesources and fesinks

* Changes include:
* Dynamic Fe uptake by phytoplankton and a quota model of their Fe limitation
* diagnostic of phytoplannkton dFe uptake (phy_dfeupt)
* Addition of chlorophyll and iron quotas as namelist inputs to the WOMBAT model, rather than hard-coded constants

* Removed feloss as a diagnostic, increased fescaven and fecoag2det sinks of dFe. Rearranged the Fe chemistry part of the code to:
* Calculate solubility of Fe3+ in solution first,
* followed by estimate of colloidal iron,
* equilibrium fraction of dFe into Fe' and Fe-L
* then precip, scav, and coag

* Following Tagliabue et al. (2023), made coagulation rate dependent on DOC and Phytoplankton biomass. Also added light as a means to increase free Fe.

* Little clean up of the code

* Removed unecessary call to wombat%kcoag_dfe

* Included a three dimensional call and output of htotal and ahtotal arrays. The htotal array is being used to calculate pH within the biogeochemical code for iron chemistry calculation of free Fe solubility.

* * added "zookz" as a new parameter controlling linear mortality (respiration) of zooplankton
* no mortality/grazing of phy or zoo at concentrations less then 1e-3 mmol C m-3
* renamed f11,f21,etc. to readable arrays that are output as diagnostics (e.g., "phygrow", "zoograz")
* rearranged code steps in biotic part

* Fixed small bug in collection of tendency terms (Step 9)

* Added "feIII", "felig", and "fecol" to diagnostic output. Made small syntax corrections given Dougie Squire's PR review.

* Registered diagnostics of feIII, fecol and felig

* Corrected long names of FeIII, felig and fecol

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Co-authored-by: Pearse Buchanan <[email protected]>
Co-authored-by: Pearse Buchanan <[email protected]>
Co-authored-by: Pearse Buchanan <[email protected]>
Co-authored-by: Pearse Buchanan <[email protected]>
Co-authored-by: Pearse Buchanan <[email protected]>
Co-authored-by: Pearse Buchanan <[email protected]>
Co-authored-by: Pearse Buchanan <[email protected]>
Co-authored-by: Pearse Buchanan <[email protected]>

Author: 9 people