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Salinity (DIC samples)

Practical salinity (PSS-78)

PSS-78key salinity_pss78NERC P01 PSLTZZ01P06 units PSUXseries salinity_pss78

CalCOFI holds 4,081 values of it from 3,457 sampling events in one dataset, 1983–2021, from the surface to 3,542 m. At 10–50 m it has risen 0.05 per decade since 1984.R Salinity tags the water masses: the California Current carries fresher Subarctic water south and the Undercurrent carries saltier water from the south; with temperature it sets density.C

4,081
values
13
flagged
i
13 of these 4,081 values (0.3 %) are flagged by their provider as questionable or bad. The Explorer, the climatology and its anomalies leave them out; do the same when you read the data yourself (cc_qual_ok_sql() in calcofi4r, qual_ok_sql() in calcofi4py).
1983–2021
years
1
dataset
0–3,542 m
depth
every month
months
33.76 g of salt in a kilogram of CalCOFI seawater, at the record’s median salinityBr⁻ 0.2 % · SO₄²⁻ 7.7 % · HCO₃⁻ 0.3 % · Cl⁻ 55.0 % · Mg²⁺ 3.7 % · Na⁺ 30.7 % · K⁺ 1.1 % · Ca²⁺ 1.2 %The quantity of dissolved ions (predominantly salt in seawater) expressed on a scale (PSS-78) based on the conductivity ratio of a seawater sample to a standard KCl solution.

Measured in 1 dataset
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One row per series, one cell per year, darker with more values — the same strip the front door draws per dataset and a species page draws per taxon. Each row is one dataset's own measurement_type; the label is written once, in the title above.

  • 4,081 values · 3,457 sampling events · 1983–2021 · 0–3,542 m · 36 grid cells · 130 cruises
    series salinity_pss78 · source column Salinity_PSS78 · flag column salinity_pss78_flag 13 flagged · 0.3 %

Explorera depth section vs normaldb-queryERDDAPThis page as JSON R · Python · Parquet

Every way in 8 ways · ERDDAP · Parquet · R · Python · JSON

Read from measurements.json of release v2026.10.21, written at release by calcofi4db::build_measurements_catalog() beside taxa.json. The catalog's index is /measurements/; the JSON-LD on this page is a schema.org/DefinedTerm in the NERC P01 term set with a PropertyValue per series.

ExplorerExplorer · a depth section vs normaldb-query
ERDDAP · Carbonate Chemistry / DICCalCOFI's own server, the Carbonate Chemistry / DIC table constrained to this series
https://erddap.calcofi.io/erddap/tabledap/calcofi_dic.html?&measurement_type=%22salinity_pss78%22
The structure 2 structures
O4S2− sulfate CHEBI:16189 · 96.063 g/mol · component
CHO3− hydrogencarbonate CHEBI:17544 · 61.016 g/mol · component

ChEBI: “A sulfur oxoanion obtained by deprotonation of both OH groups of sulfuric acid.” · RDKit 2026.03.6 from the ChEBI molfile, in the page’s ink · CC BY 4.0. ChEBI’s roles are never shown.

How it is measured Guildline Portasal 8410A salinometer, two per cruise
rosette bottle
Carbonate Chemistry / DIC · rosette bottle
Guildline Portasal 8410A salinometer, two per cruise

About 225 mL drawn from every Niskin into a numbered KIMAX bottle after three rinses; a Guildline Portasal 8410A salinometer compares the sample's conductivity with a reference seawater standard and salinity is computed from the ratio. (calcofi.org Bottle sampling methods)

flag salinity_pss78_flag13 flaggedaccuracy +/-0.003 PSU, precision 0.0003 PSU (Guildline specification)
Bottle sampling methods on calcofi.org ↗
Why it matters 4 ways to say it · EOV Subsurface salinity

Essential Ocean Variable
Subsurface salinity

the GOOS specification sheet for this Essential Ocean Variable lists it

GOOS specification sheet ↗

other ways to say why · 3
  • authored Salinity and temperature together set seawater’s density, which drives the currents and decides how deep winter mixing reaches. needs a citation before it can be the pick
  • Wikipedia Water mass source
  • Wikipedia Salinity is the saltiness or amount of salt dissolved in a body of water, called saline water. It is usually measured in g/L or g/kg. Salinity · CC BY-SA 4.0 · rev. 1368851206
The record’s own history 1 depth band against the 1993–2013 normal

Each year against the normal
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Deeper than the climatology reaches: 731 values at 0–10 m, 398 values at 50–100 m, 722 values at 100–200 m, 723 values at 200–500 m, 399 values at 500–1000 m, 1 values at 1000–2000 m, 16 values at 2000+ m have no normal to depart from, because the release’s climatology stops at its deepest built bin. Carrying it to the bottom is one argument of build_climatology() and puts these bands on the page too.

Units and range PSS-78 · 0 … 45 declared · 13 flagged

PSS-78 · P06 units PSUX

bounds0 … 45 PSS-78observed32.88 … 34.68 PSS-78flagged13baselineclimatology ✓
details
bounds
The registry declares 0 … 45 PSS-78 for salinity_pss78; a value outside it is dropped at the ingest (drop_out_of_bounds()).
observed
Carbonate Chemistry / DIC salinity_pss78 32.88 · median 33.6 · 34.68 PSS-78 (5th–95th percentile 33.16–34.29)
flags
Carbonate Chemistry / DIC salinity_pss78 salinity_pss78_flag on 4,081 of 4,081 rows: 2 4,068 · 3 12 · 4 1; qual_ok keeps 4,068. The codes are this dataset's own vocabulary, uninterpreted.
baseline
A monthly climatology exists for this measurement (the release's climatology table: 1993–2013, dataset × station × the cruise's month × 10 m bin), so the Explorer can draw anomalies against it rather than values.

The familiar scale
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Bars are each series' 5th–95th percentile, the line its minimum to maximum, the ring its median; the marks are metadata/measurement_scale.csv's, each hovering to its own source.

By depth · by month 0–3,542 m · every month

By depth
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Values per depth band at the release grain, one thin bar per series. The bands are the record's own (0-10 … 2000+ m).

By month
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Values per calendar month, one row per series: CalCOFI's quarterly cruises show as peaks in the months the ships sail.

Cite the release, v2026.10.21

Cite the release; each dataset's own citation, licence and DOI are on its page — Carbonate Chemistry / DIC. The Explorer's Share → Cite writes it for the view you make.