CTD Derived Products
CalCOFI CTD Derived Hydrographic Products
calcofi_ctd-derivedCalCOFIunstatedv2026.10.08
- years
- 1993–2026
- observations
- 1,336,529
- sampling events
- 9,350
- stations
- 113
- variables
- 9
- depth
- 1–3630 m
Overview
Hydrographic products DERIVED from the CalCOFI CTD cast profiles rather than measured: spice (spiciness at 0 dbar, TEOS-10) and the sensor-pair averaged sigma-theta at every published CTD depth; and, per cast, the mixed-layer depth (the CalCOFI legacy definition, with two alternative criteria beside it), the depth and value of the chlorophyll-a maximum and the chlorophyll-a integrated over the top 200 m, by the definitions of the CalCOFI CTD team. Computed from the full-resolution 1 m bins of the CalCOFI CTD Cast Files after the provider’s quality flags are applied.
Open with the provider
- Q06 — proposed
calcofi.org page ↗source ↗ingest notebook ↗record JSON JSON-LD
Coverage
9 variables
obs_env profile · one value at each depth of a cast · 1,336,529 values · 1993–2026 · 2 variables
sample_measurement per cast · one value for the whole cast or tow, at no depth · 63,750 values on 9,642 sampling events · 1993–2026 · 7 variables
mld_temperature_02 m 9,423mld_sigma_theta_002 m 9,180chl_max ug/L 9,079chl_max_depth m 9,079mld_sigma_theta_0125 m 8,997chl_integrated mg/m2 8,996chl_integrated_depth m 8,996
Access
Every endpoint this dataset can be reached through, grouped by how you would use it. Each name is the link; the copy button beside it copies the address. Everything is in the release record and was answered when the release was cut.
Apps that read this dataset from the release. The icons after a name are the app’s lenses — the spatial grain it shows the data at.
Every way to have the bytes, by source. Nothing here asks you to register first.
Tables from the release (Parquet)
The release’s own tables, as the parquet objects it is frozen from — the same bytes every app and package below reads. A table this dataset shares with others holds every dataset’s rows, so filter on dataset_key; a partition holds only this dataset’s. since is the release whose rows these are: an unchanged table keeps its object.
From the provider
The dataset as its provider publishes it, before CalCOFI ingested it.
The same release, from a script or a browser SQL shell.
Packages
The whole release, pinned to a version, with the citation one call away.
con <- calcofi4r::cc_get_db()
calcofi4r::cc_cite("calcofi_ctd-derived")con = calcofi4py.cc_get_db()
calcofi4py.cc_cite("calcofi_ctd-derived")DuckDB, anywhere
No CalCOFI package needed: each table above is a plain parquet object, readable by any DuckDB (or Arrow, pandas, Spark) from its URL. The path carries a content hash — a table whose rows did not change between releases keeps the same object, so nothing unchanged is stored or downloaded twice. Swap in any table above; one shared with other datasets needs WHERE dataset_key = 'calcofi_ctd-derived'. Every object of every release is listed in db-schema.
SELECT *
FROM read_parquet('https://storage.googleapis.com/calcofi-db/ducklake/tables/obs/dataset_key=calcofi_ctd-derived/c2b9fad578a3e98cfd51a43b/data_0.parquet')
LIMIT 100;SELECT *
FROM read_parquet('https://storage.googleapis.com/calcofi-db/ducklake/tables/sample_measurement/93a7425eee8669480b3c0c25/sample_measurement.parquet')
WHERE dataset_key = 'calcofi_ctd-derived'
LIMIT 100;db-query, in the browser
__TBL:obs__ is db-query’s name for the pinned release’s obs object — the hashed path above, resolved for you — so the same SQL keeps working when a release changes the object.
-- calcofi_ctd-derived in the CalCOFI release v2026.10.08
SELECT *
FROM __TBL:obs__
WHERE dataset_key = 'calcofi_ctd-derived'
LIMIT 100;Records about the data, in the standards each portal harvests.
Where this dataset is registered outside calcofi.io: each portal’s role, what it is for, the dataset’s status there and the identifier it is known by. The policy — which portal is the archive of record and why — is in Portals.
Everything here is open — nothing on calcofi.io asks you to register first. If this dataset ends up in something you build or publish, register your use so it can be credited and linked back; to hear when a release changes it, stay informed. Questions: data@calcofi.io.
Cite
This dataset's own citation. What to cite, and how, is a chapter of the docs book.
CalCOFI. (2026). CalCOFI CTD Derived Hydrographic Products (from the CalCOFI CTD Cast Files). CalCOFI.io. https://calcofi.io/workflows/ingest_calcofi_ctd-derived.htmlBibTeX
@misc{calcofi_ctd-derived,
title = {CalCOFI CTD Derived Hydrographic Products},
howpublished = {CalCOFI. (2026). CalCOFI CTD Derived Hydrographic Products (from the CalCOFI CTD Cast Files). CalCOFI.io. https://calcofi.io/workflows/ingest_calcofi_ctd-derived.html},
year = {2026}
}…and the release it came from
CalCOFI (2026). CalCOFI Integrated Database, release v2026.10.08 [Data set]. Scripps Institution of Oceanography, NOAA Fisheries, and California Department of Fish and Wildlife. https://calcofi.io/db-schema/?v=v2026.10.08BibTeX
@misc{calcofi_release_v2026_10_08,
title = {CalCOFI Integrated Database, release v2026.10.08},
author = {CalCOFI},
year = {2026},
publisher = {Scripps Institution of Oceanography, NOAA Fisheries, and California Department of Fish and Wildlife},
url = {https://calcofi.io/db-schema/?v=v2026.10.08}
}