Gsw instead of seawater

[JanStreffing]

Needs a thorough test. Not to be merged before #127

[JanStreffing]

Found a first problem. I think this happens in:

 --> compute hslice_clim:
     --> compute: temp
          --> compute depth: 100

papermill.exceptions.PapermillExecutionError:
---------------------------------------------------------------------------
Exception encountered at "In [6]":
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Cell In[6], line 7
      5 if   vname=='temp' and  which_clim.lower()=='woa18': clim_vname = 't00an1'
      6 elif vname=='salt' and  which_clim.lower()=='woa18': clim_vname = 's00an1'
----> 7 clim = tpv.load_climatology(mesh, clim_path, clim_vname, depth=depth)
      8 print(' --> elasped time to load clim: {:3.2f} min.'.format( (clock.time()-ts)/60  ))
      9 print(' --> clim uses {:3.2f} Gb:'.format(clim.nbytes/(1024**3)))

File /work/ab0246/a270092/software/tripyview/tripyview/sub_climatology.py:69, in load_climatology(mesh, datapath, vname, depth, depidx, do_zarithm, do_hinterp, do_zinterp, descript, do_ptemp, pref, do_compute, do_load, do_persist, **kwargs)
     62     #data_depth = data[coord_zlev]
     63     #data_depth = data_depth.expand_dims({dim_lat:data[coord_lat].data,
     64                                          #dim_lon:data[coord_lon].data}
     65                                         #).transpose(dim_zlev,dim_lat,dim_lon)
     66     data_depth = data[coord_zlev].expand_dims(
     67                     dict({dim_lat:data[coord_lat].data, dim_lon:data[coord_lon].data})
     68                     ).transpose(dim_zlev,dim_lat,dim_lon)
---> 69     data[vname_temp].data = sw.ptmp(data[vname_salt].data, data[vname_temp].data, data_depth )
     71 #___________________________________________________________________________
     72 # if there are multiple variables, than kick out varaible that is not needed
     73 vname_drop = list(data.keys())

AttributeError: module 'gsw' has no attribute 'ptmp'

[JanStreffing]

I think it's ok to replace ptmp from https://pythonhosted.org/seawater/eos80.html with https://teos-10.github.io/GSW-Python/_modules/gsw/_wrapped_ufuncs.html#pt_from_t. We would update from EOS80 to TEOS10, which I think is good. Need to be sure this does not clash with our obs input file or FESOM2 output units. We also have to give pref=0, which used to be a default with the old function.

gsw.pt_from_t:

sw.ptmp:

[patrickscholz]

Ich hatte das vorm urlaub auch schon mal ins auge gefasst. Hab dann aber gemerkt das man da vorsichtig sein muss. Da die gsw routinen als input nicht mehr potentielle temperatur haben sondern CT conservative temperature. Wenn mann das glaub ich korrect machen will muss man da noch einen zwischen schritt einbauen mit PT --> CT. Ich wollte das ohnehin nach dem urlaub mit machen.

[JanStreffing]

Are you sure? There is also CT to T, but this function is specifically called PT to T. Same checks should be done for the lastest commit where I switch from sw.dens to gsw.rho.