Bottle trip depth
- 156,745
- values
- 0
- flagged
- 9,134
- sampling events
- 1993–2026
- years
- 1
- dataset
- 1–3,510 m
- depth
- Jan · Feb · Mar · Apr · May · Jun · Jul · Aug · Sep · Oct · Nov
- seasons
The distance of a sensor or sampling point below the sea surface
CalCOFI holds 156,745 values of it from 9,134 sampling events in one dataset, 1993–2026, from the surface to 3,510 m. At 10–50 m it has fallen 0.64 per decade since 1993.R Pressure is how a CTD knows where it is, and depth is where the story is: off Southern California oxygen, nitrate and phosphate have changed at different rates in each layer.C
other ways to say why · 2
- Every profile in the record is placed in the water column by its pressure, so a depth error moves a value into the wrong layer rather than losing it. needs a citation before it can be the pick
- Wikipedia Pressure is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure is the pressure relative to the ambient pressure. Pressure · CC BY-SA 4.0 · rev. 1378601778
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.
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
btl_depth· source columnbtl_depthno flag at this grain
How it is measured
the Niskin's trip depth from the CTD pressure record (calcofi.org CTD FAQ circa 2020)
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.
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: 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.
i
Deeper than the climatology reaches: 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.
The record
Ways in i
Read from measurements.json of release
v2026.10.14, 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-queryi
Read from measurements.json of release v2026.10.14, 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.
SELECT * FROM read_json('…/v2026.10.14/catalog.json')
-- objects[] WHERE table = 'obs_env'
-- AND partition_value = 'btl_depth'library(calcofi4r)
con <- cc_get_db() # the promoted release
tbl(con, "obs_env") |> filter(measurement_type %in% c("btl_depth"))import calcofi4py as cc
con = cc.cc_get_db()
con.sql("SELECT * FROM obs_env WHERE measurement_type IN ('btl_depth')").df()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.
Range & quality
details
- bounds
- The registry declares
0 … 11,000 mforbtl_depth; a value outside it is dropped at the ingest (drop_out_of_bounds()). - observed
- CTD Cast Files
btl_depth1 · median 99 · 3510 m (5th–95th percentile 3–497) - flags
- CTD Cast Files
btl_depthcarries no quality code at the release grain; qual_ok keeps all 156,745. - 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.
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).
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).
- Reported depth from pressure (pre-QC) r_depth · Hydrographic Bottle · 1949–2021 · 895,370 values · P01 ADEPZZ01 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.