Add Urea units [NMOL/L]

[asdossant]

Urea data has been submitted with units of nM for cruise 49NZ20191229, but currently our parameters table only has UMOL/KG.
We decided to add Urea with units of NMOL/L (or UMOL/L) to the parameter table

Link to cruise with submitted data:
https://cchdo.ucsd.edu/cruise/49NZ20191229

[DocOtak]

I have been unable to find an instance where we have mixed SI prefixes (nano vs micro in this case). So I really hesitate to add NMOL units without making a decision about converting either the incoming data or all the existing data (like 5 cruises). Is the UMOL/L in parens a suggestion that we would be open to converting (by dividing by 1000) the incoming data?

I poke around NVS and UMOL units seem to be what they have for urea params. All of our existing data are in UMOL/KG so UMOL/L feels natural/correct, even if the numbers are small <1.

[eaitoro]

Did you find anything in NVS? I am revisiting this cruise to work on it and want to know if you found anything or if we should open up more discussion at the next meeting.

[DocOtak]

Looks like NVS is basically all umol for urea (see the units under "related" label):

• https://vocab.nerc.ac.uk/collection/P01/current/UREAMDD2/
• https://vocab.nerc.ac.uk/collection/P01/current/UREAMDD1/
• https://vocab.nerc.ac.uk/collection/P01/current/UREAAAZX/
• https://vocab.nerc.ac.uk/collection/P01/current/UREAZZZZ/
• https://vocab.nerc.ac.uk/collection/P01/current/UREAMDD2/

[eaitoro]

The decision from CCHDO meeting on Aug. 20, 2025 is to convert but preserve the input precision so we could still be reverse engineered to the originally submitted values.

UMOL/L will still need to be added.