Things learnt today by playing with GOTM

Biogeochemical models:

I downloaded the case "gotland": http://www.gotm.net/cases/v4.0/gotland.tar.gz

This configuration contains biogeochemical component, defined by 'bio.nml'.

'gotmrun.nml':

model basics: time step, time resolution, space, input/output, title, etc.

'bio.nml':

settings for biogeochemical model: which model? choice of advective schemes? etc.

In 'gotland' case, 'bio_model = 2', meaning the biogeochemical model is IOW-ERGOM (9 state variables).

There are three other models to choose from: NPZD, Suspended matter only (not sure what it is), and Fasham et al 1990 7-compartment model.

All biological models are stored in "src/extras/bio/" directory. You have to recompile GOTM (i.e. reproduce gotm_prod_GFORTRAN) if and when you want to modify these models.

I've confirmed this by modifying the parameter for IOW-ERGOM model (bio_iow.F90):

      iopt=max(0.25*I_0,I_min)

I change the default value of 0.25 to 100 (randomly selected), and recompile GOTM, then compare the results for diatoms concentration at the end of 1-year model integration by "ncdump -v dia gotland.nc" then the values were much different, as expected!

Next I should find out how to create my own configuration (e.g. via CPP keys as in NEMO? or something else?)

At this point, I still can't compile FABM (some fortran errors).