Improved and functional sediment module in PISCES

[aumont]

There is currently a sediment module in PISCES that was coded in 2006 and has not been maintained since. This module has been recoded and made functional. Furthermore, new redox reactions have been added to the module. Oxydation of organic matter by O2, NO3, Fe and SO4 are described. 10 solute species (DIC, Alkalinity, O2, NO3, NH4, Fe2+, PO4, SO4, H2S, and Si) and 8 solid species (3 POC pools with different reactivities, BSi, CaCO3, clay, Fe(OH)3, FeS) are being modeled.
The code can be activated by a cpp key, can be run in a one way or 2-way mode and can also be run offline (meaning that PISCES is not run together with the sediment model, fields are instead read in a file).
One cpp key is required when running the model offline. No cpp key has been introduced to run the sediment model online together with PISCES.