[MITgcm-devel] gchem

[Martin Losch]

Hi,

here comes my share of (hopefully not stupid) suggestions for this week.

I have several questions and suggestions about the GCHEM package:
1. There is one experiment dic_example, but testreport probably does 
not check the values of the passive tracers. Is there a way to check, 
whether I broke this experiment by my modifications other than 
acutually comparing the output fields?

2. the place of the call gchem_forcing_sep in forward_step doesn't make 
sense to me. Why isn't it called before do_fields_blocking_exchanges? I 
would like to change that, and then iMin,iMax,jMin,jMax could be set to 
1,sNx,1,sNy (instead of 1-Olx,sNx+Olx, etc) in gchem_forcing_sep and we 
wouldn't have to compute the expensive bio-forcing on the halos at all 
(I think, this causes problem with my open boundary set-up), the fields 
are exchanged anyway. This change doesn't require any work and I am 
willing to do that, but I don't know if it will break dic_example 
(probably not).
[The more complicated solution is to call gchem_forcing_sep much 
earlier, eg. after call seaice, but I am not even suggesting that, 
because it will require changing the way the time step is handled in 
all bgc_forcing.F files.]

3. gchem_fields_load calls subroutines 
(dic_fields_load/cfc_fields_load, and whatever I added in my local 
copy), but in these subroutines, files are read whose names are defined 
in GCHEM.h (WindFile, AtmospFile, etc.). Wouldn't it make more sense to 
read those files in gchem_fields_load directly? Parts of 
cfc_fields_load and dic_fields_load are identical (and for every 
bgc-model I have, I have to duplicate these files again. Also I makes 
it hard to interface gchem_fields_load with the exf-package (I am 
probably the only one who wants to do that).

Martin