[Issue]: IOS datasets Salinity variables to CTD specific BODC

[JessyBarrette]

Level

High

Issue Description

A lot of the different CTD datasets from IOS rigth now are refering the Salinity variables with are identified within the IOS files as:

• salinity
• salinity: pre-1978
• salinity:bottle
• salinity:t0:c0
• salinity:t1:c1

As SDN:P01::PSALST01 : Practical salinity of the water body by CTD and computation using UNESCO 1983 algorithm while often the first three variable names are referering salinity measurement made from bottles.

This is applies to the following datasets:

• 2

• 19

• 3

Issue Solution

It would be more appripropriate to attach those different values to a more appropriate BODC term like the followings: practical salinity

• SDN:P01::PSALBSTX: Practical salinity of the water body by bench salinometer and computation using UNESCO 1983 algorithm
• SDN:P01::SSALBSTX: Salinity of the water body by bench salinometer

and/or a more broader terms:

• SDN:P01::PSALZZXX: Practical salinity of the water body by computation using UNESCO 1983 algorithm
• SDN:P01::ODSDM021: Salinity of the water body

We can also improve the mapping of the different ctd specific salinity variables by using a combination of variable names and instrument.

Relevant extra information (log output,etc.)

No response

[guanlu129]

salinity:t0:c0 is from CTD measurement. Should be appropriated to use SDN:P01::PSALST01? salinity:t1:c1 is also from CTD measurement. Should be appropriate to use SDN:P01::PSALST01?

[guanlu129]

no variable is shown as salinity in OSD data archive.

[guanlu129]

UBC and MEDS files use salinity: pre-1978 in unit of ppt. There's limited information in the files about how the salinity was measured. Should we use the broader term: [SDN:P01::ODSDM021]: Salinity of the water body for UBC and MEDS files?

[guanlu129]

salinity:bottle indicates salinity measurements from bottle samples. There are three salinity variables from bottle samples: salinity:bottle () salinity:bottle (PSS-78) salinity:bottle (ppt)

So should be appropriate to use [SDN:P01::SSALBSTX]: Salinity of the water body by bench salinometer for salinity:bottle ()?

[JessyBarrette]

As of now all salinity data in units of PPT gets mapped to a not unit specific BODC like

• SDN:P01::SSALST01: Salinity of the water body by CTD
• SDN:P01::SSALBSTX: Salinity of the water body by bench salinometer

None is mapped to OSDDM021 yet but we could add them.

All PPT and pre-1978 units are converted to practical salinity by using the TEOS-10 equation. gsw.SP_from_SK

[JessyBarrette]

Here's the full list of salinity variables detected

variable	units
salinity	PSS-78|PPS78
salinity	ppt|PPT
salinity	ppt|PPT
salinity: practical	PSS-78|PSU
salinity: pre-1978	PPT
salinity: pre-1978	PPT
salinity:bottle	PPT|ppt
salinity:bottle	PPT
salinity:bottle	PSS-78
salinity:bottle
salinity:ctd	PSS-78
salinity:cur	PSS-78
salinity:cur	ppt
salinity:t0:c0	none|PSS-78
salinity:t1:c1	PSS-78
salinity:upcast	PSS-78

[guanlu129]

Two questions to confirm: 1) could we map multiple BODC standard parameters for each variable in ios data file? 2) "All PPT and pre-1978 units are converted to practical salinity by using the TEOS-10 equation. gsw.SP_from_SK" - does this happen in file conversion?

[JessyBarrette]

1. could we map multiple BODC standard parameters for each variable in ios data file? yes to both of them. Right now we're using this to generate multiple BODCs for temperature data as an example and planning to do the same for the salinity.

2. "All PPT and pre-1978 units are converted to practical salinity by using the TEOS-10 equation. gsw.SP_from_SK" - does this happen in file conversion?

Yes, it would happend there.

Generally the new netcdf files would contains more variables than the original ios file to handle the different BODC terms.