Regarding the issue of conducting iron fertilization experiments in MARBL

[shiyao]

Hi,

I'm a trainee of cesm2.1.3, I am currently trying to conduct some experiments on iron fertilization in the model, such as fertilizing the Southern Ocean and the Pacific Ocean for five consecutive years, or fertilizing a certain month in these regions, etc. I found three variables related to iron_match (liron_patch; iron_patch_flux_filename; iron_patch_month) in ecosys_foring_mod.F90 file of the model, which confused me a bit. How can I modify these parameter settings to conduct an iron fertilization experiment? Also, how did I pass on the modifications to these parameters to the organism?

my case is --compset GIAF_JRA --res TL319_g17

Any sugguestions will be quite helpful for me to solve this problem.

Thanks very much.

 

[mlevy]

Sorry for the delayed response! I suspect that the iron patch code is out-dated, and will not work with the current model configuration without some modifications. Older versions of CESM would read dust deposition and iron deposition from forcing files, and by setting

liron_patch_file = .true.
iron_patch_month = [integer between 1 and 12]
iron_patch_flux_filename = [netcdf file]

You could add the flux from a given file to the pre-defined fluxes in a given month. More recently, the atmosphere model passes dust and black carbon fluxes to the ocean through the coupler, and POP2 computes iron fluxes based on these. If that is the behavior you want (applying additional iron flux in a given month), let me know and I can try to walk you through the process... but it'll be pretty complicated, because the existing code builds upon the expectation that POP will be reading iron flux from a file rather than computing it based on fields from the coupler.