Dissolved inorganic carbon
µmol/kgkey dicNERC P01 TCO2MSXXP06 units KGUMseries dic
CalCOFI holds 4,236 values of it from 3,502 sampling events in one dataset, 1983–2021, from the surface to 3,542 m. At 10–50 m it has risen 6.82 per decade since 1984.R The ocean has taken up a large share of the carbon dioxide people have emitted, and dissolved inorganic carbon is where it sits; with alkalinity it fixes pH and the carbonate that shells are built from.C
- 4,236
- values
- 95
- flagged
i
95 of these 4,236 values (2.2 %) 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
Measured in
1 dataset
i
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.
i
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.
-
series
dic· source columnDIC· flag columndic_flag95 flagged · 2.2 %
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 v2026.11.05, 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-querySELECT * FROM read_json('…/v2026.11.05/catalog.json')
-- objects[] WHERE table = 'obs_env'
-- AND partition_value = 'dic'library(calcofi4r)
con <- cc_get_db() # the promoted release
tbl(con, "obs_env") |> filter(measurement_type %in% c("dic"))import calcofi4py as cc
con = cc.cc_get_db()
con.sql("SELECT * FROM obs_env WHERE measurement_type IN ('dic')").df()The structure 3 structures
ChEBI: “A one-carbon compound with formula CO2 in which the carbon is attached to each oxygen atom by a double bond. A colourless, odourless gas under normal conditions, it is produced during respiration by all animals, fungi and microorganisms that depend directly or indirectly on living or decaying plants for food.” · RDKit 2026.03.6 from the ChEBI SMILES (the molfile is vertical), in the page’s ink · CC BY 4.0. ChEBI’s roles are never shown.
How it is measured CO2 gas analyser (DIC), potentiometric titrator (alkalinity)
Samples drawn from the Niskins at selected stations and analysed ashore; total inorganic carbon and alkalinity are measured, from which pH and pCO2 can be calculated, calibrated to the certified reference materials Scripps prepares for the world. (NCEI accession 0301029 (DIC/alkalinity instruments); calcofi.org Bottle sampling methods)
NCEI accession 0301029 (DIC/alkalinity instruments); Bottle sampling methods on calcofi.org ↗Why it matters 6 ways to say it · EOV Inorganic carbon
the GOOS specification sheet for this Essential Ocean Variable lists it, and asks
GOOS asks
- How is the ocean carbon content changing?
- What are rates and impacts of ocean acidification?
GOOS specification sheet ↗ · quoted, not copied
Why CalCOFI samples it, in its own words
CalCOFI samples it for first, the long-term characterization of the inorganic carbon system and its response to changing ocean climate, and second, measurements of pH in the coastal zone in order to monitor the impact of ‘corrosive’ waters on benthic ecosystems in the Southern California Bight. calcofi.org ↗
other ways to say why · 5
- The ocean sink is one of the terms the global carbon budget is balanced on, and it is measured with exactly this quantity. needs a citation before it can be the pick
- GOOS asks How is the ocean carbon content changing? source
- GOOS asks What are rates and impacts of ocean acidification? source
- calcofi.org CalCOFI samples it for first, the long-term characterization of the inorganic carbon system and its response to changing ocean climate, and second, measurements of pH in the coastal zone in order to monitor the impact of ‘corrosive’ waters on benthic ecosystems in the Southern California Bight. source
- Wikipedia Dissolved inorganic carbon (DIC) is the sum of the aqueous species of inorganic carbon in a solution. Carbon compounds can be distinguished as either organic or inorganic, and as dissolved or particulate, depending on their composition. Dissolved inorganic carbon · CC BY-SA 4.0 · rev. 1294570528
The record’s own history 1 depth band against the 1993–2013 normal
Each year against the normal i
Deeper than the climatology reaches: 820 values at 0–10 m, 392 values at 50–100 m, 707 values at 100–200 m, 711 values at 200–500 m, 382 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.
i
Deeper than the climatology reaches: 820 values at 0–10 m, 392 values at 50–100 m, 707 values at 100–200 m, 711 values at 200–500 m, 382 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 µmol/kg · 0 … 5000 declared · 95 flagged
µmol/kg (umol/kg in metadata/measurement_type.csv) · P06 units KGUM
details
- bounds
- The registry declares
0 … 5000 µmol/kgfordic; a value outside it is dropped at the ingest (drop_out_of_bounds()). - observed
- Carbonate Chemistry / DIC
dic1934 · median 2082 · 2368 µmol/kg (5th–95th percentile 1987–2315) - flags
- Carbonate Chemistry / DIC
dicdic_flagon 4,236 of 4,236 rows:24,141 ·350 ·444 ·91; qual_ok keeps 4,141. 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 i
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.
i
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 i
Values per depth band at the release grain, one thin bar per series. The bands are the
record's own (0-10 … 2000+ m).
i
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 i
Values per calendar month, one row per series: CalCOFI's quarterly cruises show as peaks in
the months the ships sail.
i
Values per calendar month, one row per series: CalCOFI's quarterly cruises show as peaks in the months the ships sail.
Cite the release, v2026.11.05
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.