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Measurement · Physical Oceanography · °C

Bottle temperature

NERC P01 TEMPPR01P06 units UPAA degCkey btl_temperature series btl_temperature
141,771
values
0
flagged
8,146
sampling events
1993–2025
years
1
dataset
1–3,510 m
depth
Jan · Feb · Mar · Apr · May · Jun · Jul · Aug · Sep · Oct · Nov
seasons
What

The degree of hotness of the water column expressed against a standard scale. Includes both IPTS-68 and ITS-90 scales.

How
CTD sensor

Sea-Bird CTD, pumped dual temperature sensors

CTD FAQ circa 2020 on calcofi.org ↗

EOV Subsurface temperature

CalCOFI holds 141,771 values of it from 8,146 sampling events in one dataset, 1993–2025, from the surface to 3,510 m. At 10–50 m it has risen 0.17 per decade since 1993.R Temperature sets the water’s density, and so the layering that decides whether deep nutrients reach the sunlit surface; off California the warm years are El Niño years and marine heatwaves.C

other ways to say why · 3
  • authored A warm year off California is usually a lean one: warmer, more layered water brings fewer nutrients up, and the plankton the rest of the food web eats decline. needs a citation before it can be the pick
  • Wikipedia Marine heatwave source
  • Wikipedia Sea surface temperature is the temperature of ocean water close to the surface. The exact meaning of surface varies in the literature and in practice. Sea surface temperature · CC BY-SA 4.0 · rev. 1374459881

The measurement

Measured in
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.

  • CTD Cast Files 141,771 values · 8,146 sampling events · 1993–2025 · 1–3,510 m · 91 grid cells · 114 cruises
    series btl_temperature · source column btl_temp no flag at this grain

How it is measured

CTD Cast Files · CTD sensor
Sea-Bird CTD, pumped dual temperature sensors

The average of two pumped Sea-Bird temperature sensors in 1 m bins; the pumps keep water moving past the sensors regardless of ship roll, and the CTD is lowered at 30 m/min to 100 m then 60 m/min to 515 m to limit wire-angle stress and improve resolution through the thermocline. (calcofi.org CTD FAQ circa 2020)

no flag at this grain
CTD FAQ circa 2020 on calcofi.org ↗

Why it matters

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.

The record’s own history
i

Deeper than the climatology reaches: 6,902 values at 500–1000 m, 90 values at 1000–2000 m, 24 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.

Essential Ocean Variable
Subsurface temperature

the GOOS specification sheet for this Essential Ocean Variable lists it

GOOS specification sheet ↗

The record

Ways in
i

Read from measurements.json of release v2026.09.11, 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 · 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=%22btl_temperature%22

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).

By month
i

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

Range & quality

bounds-2 … 40 °Cobserved1.52 … 23.56 °Cflagged0baselineclimatology ✓
details
bounds
The registry declares -2 … 40 °C for btl_temperature; a value outside it is dropped at the ingest (drop_out_of_bounds()).
observed
CTD Cast Files btl_temperature 1.52 · median 10.64 · 23.56 °C (5th–95th percentile 6.179–17.58)
flags
CTD Cast Files btl_temperature carries no quality code at the release grain; qual_ok keeps all 141,771.
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.

Related measurements
i

The same quantity from another platform or another kind of sample, each its own page and never merged into this one: a dataset's own bottle samples would count that dataset twice, an underway intake is not a cast, and a replicate is not a mean. The reason is the record's (related[].why).

  • Temperature temperature · temperature_ave · Hydrographic Bottle · CTD Cast Files · 1949–2026 · 1,575,559 values · P01 TEMPPR01 the same quantity from the CTD files' own bottle samples — plausibly the same physical bottles, so merging them would count the bottle dataset twice

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.