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nvs-vocabs / ereefs

A repository for the management of issues related to vocabularies used by the eReefs project.
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Sediment porosity terms #26

Closed danibodc closed 2 years ago

danibodc commented 2 years ago

R.e. the following parameters:

Sediment porosity (model: 'porosity', sensor: '', standard: ''') Sediment porosity in Sediment, Sediment porosity sediment (model: 'porosity_sed', sensor: '', standard: ''')

  1. Please could you clarify the difference between these terms?

  2. Our existing terms for porosity are modelled as below; we are assuming that your terms should be 'of wet sediment', but please could you confirm?

    • Concentration of water {H2O CAS 7732-18-5} {porosity} per unit volume of sediment
    • Concentration of water {H2O CAS 7732-18-5} {porosity} per unit volume of wet sediment by drying and gravimetry
markebaird commented 2 years ago

All tracers have a value in the water column and in either the sediment (if they are particulate) or sediment porewater (if they are dissolved). Thus porosity has a value in the water which is 1. I would suggested that we use {porosity} per unit volume of sediment.

danibodc commented 2 years ago

Hi @markebaird

Many thanks. Please could you confirm if the below represents the correct matrix for each term?

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CSIRO Parameter | Proposed Matrix (S26) -- | -- Sediment porosity (model: 'porosity', sensor: '', standard: ''') | per unit volume of sediment pore water Sediment porosity in Sediment, Sediment porosity sediment (model: 'porosity_sed', sensor: '', standard: ''') | per unit volume of sediment

Thanks, Dani

markebaird commented 2 years ago

Sediment porosity in Sediment is correct. Just checking for your readability, the value is 1 if there is no sediment and all pore water and 0 if there is no pore water and all sediment. Typically it 0.3-0.7.

Sediment porosity is a nonsensical because it is referring to sediment porosity in the water body. It's matrix should be "per unit volume of water body". I might try and remove it from the files. The model generates outputs variables XXX and XXX_sed for all tracers. But in this case porosity is not populated by the model (while porosity_sed is). Can I suggest we don't produce vocab entries for it?

sharon-tickell commented 2 years ago

@markebaird : noted on that explanation, and I agree we can move that one to the 'ignore' list if it's nonsensical.

danibodc commented 2 years ago

Ok many thanks @sharon-tickell and @markebaird! In that case, we will not create a 'Sediment porosity' term.

To match the modelling of our existing 'porosity' terms, we will model the 'Sediment porosity in sediment' term as below:

Concentration of water {H2O CAS 7732-18-5} {porosity} per unit volume of wet sediment by model prediction

Many thanks!