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Chlorophyll integration depth

Depth reached by chl_integrated (200 m unless the cast is shallower)

mkey chl_integrated_depthP06 units ULAAseries chl_integrated_depth

one value per cast One value per cast. This measurement is worked out once for each cast rather than read at every depth, so it has no depth profile and no anomaly against a normal; its values are rows of sample_measurement, not of obs_env.

CalCOFI holds 9,171 values of it from 9,171 sampling events in one dataset, 1993–2026, one per cast.R This is how deep chl_integrated reached, 200 m unless the cast was shallower, and it is there so a short column is not compared with a full one.C

9,171
values
0
flagged
1993–2026
years
1
dataset
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.

  • 9,171 values · 9,171 sampling events · 1993–2026 · 109 grid cells · 136 cruises
    series chl_integrated_depth · source column est_chlorophyll_a_sta_corr one value per cast no flag at this grain no P01 concept

Explorerdb-queryThis page as JSON R · Python · Parquet

Every way in 6 ways · 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.

Explorerdb-query
Parquetsample_measurement holds one row per cast and measurement_type, in the content-addressed store — resolved through the release catalog, never a path built by hand
SELECT * FROM read_json('…/v2026.10.21/catalog.json')
-- objects[] WHERE table = 'sample_measurement'
-- then filter the rows:
--   measurement_type IN ('chl_integrated_depth')
How it is measured Computed from the CTD fluorometer profile (corrected to bottle chlorophyll-a)
CTD sensor
CTD Derived Products · CTD sensor
Computed from the CTD fluorometer profile (corrected to bottle chlorophyll-a)

The depth chl_integrated reached: 200 m unless the cast is shallower. (the record's own derivation (measurement_type.csv))

no flag at this grain
Why it matters 3 ways to say it · EOV Phytoplankton biomass and diversity
Essential Ocean Variable
Phytoplankton biomass and diversity

the GOOS specification sheet for this Essential Ocean Variable lists it

GOOS specification sheet ↗

other ways to say why · 2
  • authored On the shelf it is the cast’s own depth; offshore it is 200 m. needs a citation before it can be the pick
  • Wikipedia The deep chlorophyll maximum (DCM), also called the subsurface chlorophyll maximum, is the region below the surface of water with the maximum concentration of chlorophyll. The DCM generally exists at the same depth as the nutricline, the region of the ocean where the greatest change in the nutrient concentration occurs with depth. Deep chlorophyll maximum · CC BY-SA 4.0 · rev. 1374126571
Units and range m · 0 … 200 declared · 0 flagged

m · P06 units ULAA

bounds0 … 200 mobserved3 … 200 mflagged0baselineno climatology
details
bounds
The registry declares 0 … 200 m for chl_integrated_depth; a value outside it is dropped at the ingest (drop_out_of_bounds()).
observed
CTD Derived Products chl_integrated_depth 3 · median 200 · 200 m (5th–95th percentile 21–200)
flags
CTD Derived Products chl_integrated_depth carries no quality code at the release grain; qual_ok keeps all 9,171.
baseline
No climatology row is built for this measurement, so the Explorer draws values, not anomalies.
derivation
calcofi4db::ctd_integrate(): min(200, deepest good bin) (questions Q02)

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.

By month every month

By month
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, v2026.10.21

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