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LTL_dataset for OSMOSE model

Dear Sir/Ma'am,
 
We have the following queries about ltl_biomass file that OSMOSE model requires as it's input
 
Query 1
We have observed that the ltl_biomass file has got its values masked over the land area associated with the Southern Benguela region. Is it necessary to have the ltl_biomass values over the land region to be masked while preparing the LTL file?
 
Query 2
As an alternative to masking the ltl_biomass values over land area, can we use flag values such as zero or negative values to represent the non-availability ltl_biomass over land area and leave it as such without providing any masking? 
 
Query 3
Would OSMOSE model look only for ltl_biomass values over ocean cells ( represented as 0 in grid-mask file) if we were to provide the LTL data without masking?
 
 
Kind regards,
Tarun Joseph

Dear Tarun,

Q1. If you are using the same grid for Osmose and the LTL model, then it is not necessary to have the ltl_biomass values masked over the land, as the mask is provided by the grid file. Consequently Osmose will never look at LTL values that are over the land.

Q2. That is actually what is done in the demo OSM configuration. In the NetCDF file I use negative values (-99.) and I set the NetCDF variable attribute _FillValue to -99.

http://cfconventions.org/cf-conventions/v1.6.0/cf-conventions.html#missi...

Q3. It is correct. Osmose will look for LTL values were the fish schools are located, and thanks to the grid mask and the maps they can only move to ocean cells.

Cheers, Philippe