Measurement · Productivity & Pigments · µg/L

Est. chlorophyll-a cruise-corrected

The registry carries no authored label for this measurement, so the name above is the canonical series' own description in metadata/measurement_type.csv (variable.csv holds the authored labels, five today).

P06 units UGPL ug/Lkey est_chlorophyll_a_cruise_corr series est_chlorophyll_a_cruise_corr

320,229
values: 9,225
sampling events: 1993–2025
years: 1
dataset: 1–200 m
depth: Jan · Feb · Mar · Apr · May · Jun · Jul · Aug · Sep · Oct · Nov
seasons

Heads-up The est_chlorophyll_a_cruise_corr series from CTD Cast Files carries no flag at this grain, so its values cannot be screened this way.

Measured in

CTD Cast Files 320,229 values · 9,225 sampling events · 1993–2025 · 1–200 m · 96 grid cells · 128 cruises

series est_chlorophyll_a_cruise_corr · source column est_chl_cruise_corr no flag at this grain no P01 concept

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.

By depth

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

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

Range & quality

bounds: The registry declares 0 … 1000 µg/L for est_chlorophyll_a_cruise_corr; a value outside it is dropped at the ingest (drop_out_of_bounds()).
observed: CTD Cast Files est_chlorophyll_a_cruise_corr 0 · median 0.1739 · 210.8 µg/L (5th–95th percentile 0.0157–2.024)
flags: CTD Cast Files est_chlorophyll_a_cruise_corr carries no quality code at the release grain; qual_ok keeps all 320,229.
baseline: A monthly climatology exists for this measurement (the release's climatology table: 1993–2013, dataset × grid cell × calendar month × 10 m bin), so the Explorer can draw anomalies against it rather than values.
derivation: Fluorometer voltage converted to chlorophyll-a by regression against bottle chlorophyll-a, applied to the 1 m bin-averaged voltage over 0-200 m ONLY - undefined deeper by construction, not by absence of data. Bottle-corrected with ONE regression per cruise, fitted from 4-second-averaged sensor data against all the cruise's bottles (n ~ 1400, fliers omitted).

Ways in

Explorermaps, sections and time series of this measurement — opens prefilled
https://calcofi.io/explore/?var=est_chlorophyll_a_cruise_corr
Explorer · a depth section vs normalthe newest cruise's section against the climatology baseline
https://calcofi.io/explore/?lens=section&var=est_chlorophyll_a_cruise_corr&anom=1
db-querySQL in your browser — the shell opens with this query
https://calcofi.io/db-query/?sql=SELECT+%2A+FROM+__TBL%3Aobs_env__+WHERE+measurement_type+%3D+%27est_chlorophyll_a_cruise_corr%27+LIMIT+100%3B
ERDDAP · CTD Cast FilesCalCOFI's own server, the CTD Cast Files table constrained to this series
https://erddap.calcofi.io/erddap/tabledap/calcofi_ctd-cast.html?&measurement_type=%22est_chlorophyll_a_cruise_corr%22

Parquetobs_env is partitioned by measurement_type in the content-addressed store — resolved through the release catalog, never a path built by hand

SELECT * FROM read_json('…/v2026.09.10/catalog.json')
-- objects[] WHERE table = 'obs_env'
--   AND partition_value = 'est_chlorophyll_a_cruise_corr'

library(calcofi4r)
con <- cc_get_db()                      # the promoted release
tbl(con, "obs_env") |> filter(measurement_type %in% c("est_chlorophyll_a_cruise_corr"))

Python

import calcofi4py as cc
con = cc.cc_get_db()
con.sql("SELECT * FROM obs_env WHERE measurement_type IN ('est_chlorophyll_a_cruise_corr')").df()

This page as data

JSONthis measurement's entry of the release record, verbatim
https://calcofi.io/measurements/est_chlorophyll_a_cruise_corr.json

Read from measurements.json of release v2026.09.10, 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.

Cite

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