WOMBAT: Update iron surface flux forcing

[dougiesquire]

The iron surface flux forcing file currently used by WOMBAT is dated and of mostly unknown origin. We should update to a more up-to-date product will full provenance.

Note this is actually a configuration issue, but I'm opening here for best visibility for those who will do the work.

[anton-seaice]

The existing file uses a very strange calendar:

        double time(time) ;
                time:_FillValue = NaN ;
                time:axis = "T" ;
                time:modulo = "y" ;
                time:units = "days since 0001-01-01" ;
                time:calendar = "julian" ;
                time:_Storage = "chunked" ;
                time:_ChunkSizes = 512 ;
                time:_Endianness = "little" ;

It looks like the data is a climatology, so a better practice would be to use a proleptic_gregorian calendar, and specify climatology bounds - see https://cfconventions.org/cf-conventions/cf-conventions.html#climatological-statistics

[pearseb]

Hi Dougie. I've found an updated soluble iron deposition flux.

The file is:
Hamiltonetlal2019_MIMIv1.0_Iron_ConcDep_MonMean.nc

the variable we want to use is called "SFEDEP" --> monthly mean soluble Fe deposition

the file is downloaded from here:
http://www.geo.cornell.edu/eas/PeoplePlaces/Faculty/mahowald/dust/Hamiltonetal2019/

The paper that is tied to this dataset is:
https://gmd.copernicus.org/articles/12/3835/2019/gmd-12-3835-2019.html

[pearseb]

Just wanna hold off on this for a second... Been chatting with someone high up in the aeolian deposition world and am thinking we should use a different set of fields.

[pearseb]

Okay I have had further chats with Douglas Hamilton about this. For the immediate term, he suggests we use these files:

Hamilton2020_README.txt (4.36 KB)
CESM2CAM6-MIMI_1980-2015_Dust_DailyDep_Hamiltonetal2020.zip (2.43 GB)
CESM2CAM6-MIMI_1980-2015_SolFe_Anth_DailyDep_Hamiltonetal2020.zip (2.41 GB)
CESM2CAM6-MIMI_1980-2015_SolFe_DailyDep_Hamiltonetal2020.zip (2.42 GB)
CESM2CAM6-MIMI_1980-2015_SolFe_Dust_DailyDep_Hamiltonetal2020.zip (2.42 GB)

I believe that the one you want to use is CESM2CAM6-MIMI_1980-2015_SolFe_DailyDep_Hamiltonetal2020.zip, which contains:

• CESM2CAM6-MIMI_1980-2015_SolFe_DailyDep_Hamiltonetal2020.nc
  (not sure why it was stored as a .zip file)

We should calculate a daily climatology from this dataset using all years as an estimate of present day soluble Fe deposition to the ocean.

Citation: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020GL089688
Data is available from the Cornell eCommons repository: https://doi.org/10.7298/xqqj-qk90