Underway pH
Seawater pH
key sw_phno NERC concept says exactly thisseries sw_ph
CalCOFI holds 2,473 values of it from 2,473 sampling events in one dataset, 2016–2018, at the surface.R Upwelling brings water that is naturally low in pH and carbonate onto the shelf; ocean acidification pushes it further toward water that is corrosive to shells.C
- 2,473
- values
- 0
- flagged
- 2016–2018
- years
- 1
- dataset
- surface
- depth
- 3 of 12
- 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
sw_ph· source columnsw_phno flag at this grain no P01 concept
Explorerdb-queryERDDAPThis page as JSON R · Python · Parquet
Every way in 7 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.
Explorerdb-querySELECT * FROM read_json('…/v2026.11.05/catalog.json')
-- objects[] WHERE table = 'obs_env'
-- AND partition_value = 'sw_ph'library(calcofi4r)
con <- cc_get_db() # the promoted release
tbl(con, "obs_env") |> filter(measurement_type %in% c("sw_ph"))import calcofi4py as cc
con = cc.cc_get_db()
con.sql("SELECT * FROM obs_env WHERE measurement_type IN ('sw_ph')").df()How it is measured underway, on the mast
Why it matters 5 ways to say it · EOV Inorganic carbon
the GOOS specification sheet for this Essential Ocean Variable lists it, and asks
GOOS asks
- What are rates and impacts of ocean acidification?
GOOS specification sheet ↗ · quoted, not copied
other ways to say why · 4
- Lower pH means less carbonate in the water, and the shells of pteropods off California already show dissolution where corrosive water reaches the surface. needs a citation before it can be the pick
- GOOS asks What are rates and impacts of ocean acidification? source
- Wikipedia PH source
- Wikipedia Ocean acidification is the ongoing decrease in the pH of the Earth's ocean. Between 1950 and 2020, the average pH of the ocean surface fell from approximately 8.15 to 8.05. Ocean acidification · CC BY-SA 4.0 · rev. 1372947827
The record’s own history no climatology to depart from
Each year against the normal i
i
The release builds no climatology for this measurement, so there is no normal to draw a departure from.
Units and range 6 … 9 declared · 0 flagged
No unit in the registry.
details
- bounds
- The registry declares
6 … 9forsw_ph; a value outside it is dropped at the ingest (drop_out_of_bounds()). - observed
- Underway Meteorological (METS)
sw_ph8.269 · median 8.409 · 8.829 (5th–95th percentile 8.369–8.652) - flags
- Underway Meteorological (METS)
sw_phcarries no quality code at the release grain; qual_ok keeps all 2,473. - baseline
- No climatology row is built for this measurement, so the Explorer draws values, not anomalies.
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 surface · 3 of 12 months
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 — Underway Meteorological (METS). The Explorer's Share → Cite writes it for the view you make.