Specific volume anomaly
10⁻⁸ m³/kgkey specific_volume_anomalyP06 units UMKSseries specific_volume_anomaly
CalCOFI holds 550,275 values of it from 7,622 sampling events in one dataset, 1993–2026, from the surface to 3,541 m. At 200–500 m it has fallen 1.56 per decade since 1993.R Dynamic height is the tilt of the sea surface the currents balance: mapped across the CalCOFI grid it is how the California Current and the Undercurrent were first described season by season.C
- 550,275
- values
- 0
- flagged
- 1993–2026
- years
- 1
- dataset
- 1–3,541 m
- depth
- 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.
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
specific_volume_anomaly· source columnsva· flag columnsvaqno bound declared range suspect · no bound no P01 concept
Explorera depth section vs normaldb-queryERDDAPThis page as JSON R · Python · Parquet
Every way in 8 ways · ERDDAP · Parquet · R · Python · JSON
Read from measurements.json of release v2026.11.05, 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-querySELECT * FROM read_json('…/v2026.11.05/catalog.json')
-- objects[] WHERE table = 'obs_env'
-- AND partition_value = 'specific_volume_anomaly'library(calcofi4r)
con <- cc_get_db() # the promoted release
tbl(con, "obs_env") |> filter(measurement_type %in% c("specific_volume_anomaly"))import calcofi4py as cc
con = cc.cc_get_db()
con.sql("SELECT * FROM obs_env WHERE measurement_type IN ('specific_volume_anomaly')").df()How it is measured Computed from the cast profile
A derived hydrographic quantity computed from the cast profile, not sensed directly. (the record's own derivation (measurement_type.csv))
Why it matters 3 ways to say it
other ways to say why · 2
- It is computed from temperature and salinity down a cast, so it carries whatever those two series carry. needs a citation before it can be the pick
- Wikipedia A geostrophic current is an oceanic current in which the pressure gradient force is balanced by the Coriolis effect. The direction of geostrophic flow is parallel to the isobars, with the high pressure to the right of the flow in the Northern Hemisphere, and the high pressure to the left in the Southern Hemisphere. Geostrophic current · CC BY-SA 4.0 · rev. 1344173703
The record’s own history 6 depth bands against the 1993–2013 normal
Each year against the normal i
Deeper than the climatology reaches: 1,777 values at 1000–2000 m, 1,085 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: 1,777 values at 1000–2000 m, 1,085 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.
Units and range 10⁻⁸ m³/kg · no bound declared declared · 0 flagged
10⁻⁸ m³/kg (10^-8 m3/kg in metadata/measurement_type.csv) · P06 units UMKS
details
- bounds
- No physical bound is declared for this series in metadata/measurement_type.csv, so nothing is enforced at the ingest and the range below is simply what the release carries.
- observed
- CTD Cast Files
specific_volume_anomaly−63,921 · median 171.4 · 5723 10⁻⁸ m³/kg (5th–95th percentile 114.8–359.9) - flags
- CTD Cast Files
specific_volume_anomalycarries no quality code at the release grain (its source column issvaq); qual_ok keeps all 550,275. - 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.
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.
By depth · by month 1–3,541 m · every month
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.
Cite the release, v2026.11.05
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.