#oceanography

Seawater oceanography maths as an API, computed locally and deterministically from the standard equations — the density, freezing-point and chlorinity numbers an oceanographer, marine scientist or aquarist works with. The density endpoint gives the seawater density and σt from salinity and temperature using the full UNESCO EOS-80 one-atmosphere equation of state — it reproduces the official check value of 1027.675 kg/m³ at 35 PSU and 5 °C exactly — around 1,025 kg/m³, rising with salinity and falling with temperature, the two drivers of the ocean's density-driven circulation where cold salty water sinks. The freezing-point endpoint gives the freezing point from salinity (Millero): about −1.9 °C at the ocean's typical 35 ppt, and because salt also pushes the temperature of maximum density below freezing, seawater keeps overturning and cooling all the way down instead of stratifying like a freshwater lake — why the open ocean rarely freezes outside the polar seas. The chlorinity endpoint converts between salinity and chlorinity through the Knudsen relation S = 1.80655 × Cl, the classic titration measure that the constant major-ion proportions of seawater make reliable. Everything is computed locally and deterministically, so it is instant and private. Ideal for oceanography and marine-science tools, ocean-model and sensor pipelines, aquarium and aquaculture apps, and environmental dashboards. Pure local computation — no key, no third-party service, instant. Surface (atmospheric-pressure) forms. 3 compute endpoints. For the speed of sound in seawater use a sonar API; for general colligative properties a colligative-properties API.

api.oanor.com/seawater-api

Underwater-sound and sonar maths as an API, computed locally and deterministically — the speed, absorption and ranging numbers a marine engineer, sonar developer or oceanographer works with. The sound-speed endpoint gives the speed of sound in seawater from the Mackenzie nine-term equation: about 1,500 m/s — far faster than in air — rising with temperature, salinity and depth, so a profile of 25 °C, 35 ppt at 1,000 m gives 1,550.7 m/s. Because the speed varies with depth, sound rays bend and form the SOFAR channel that carries whale song and signals across whole oceans. The absorption endpoint gives Thorp's sound-absorption coefficient in dB per km against frequency, with the loss over a path: seawater swallows high frequencies fast, which is why long-range sonar and whale calls are low-pitched while high-frequency sonar gives sharp images only at short range. The echo-range endpoint turns an echo sounder's or sonar's two-way travel time into the range or depth — distance = sound speed × time ÷ 2 — so a one-second round trip at 1,500 m/s is a target 750 m away, its accuracy resting on the assumed sound speed. Everything is computed locally and deterministically, so it is instant and private. Ideal for sonar and hydrophone tools, marine-survey and bathymetry apps, ocean-acoustics research, and AUV/ROV navigation utilities. Pure local computation — no key, no third-party service, instant. Standard-equation estimates over their valid ranges. 3 compute endpoints. For the speed of sound in air and Mach use a Mach-number API; for decibels a sound-level API.

api.oanor.com/sonar-api

The World Register of Marine Species (WoRMS) as an API — the authoritative, expert-curated taxonomic register of the world's marine life, maintained by a global network of taxonomists. WoRMS provides the accepted scientific names, naming authorities, taxonomic status and synonymy, full classification and vernacular (common) names for marine species. /v1/search?name=Orcinus orca searches species by scientific name (set fuzzy=true for partial matching, marine_only=true to restrict to marine taxa), returning each match's AphiaID (WoRMS' stable identifier), accepted name, authority, rank, taxonomic status, valid name and higher classification. /v1/species?id=137102 returns a species' full record by AphiaID — name and authority, status, the kingdom-to-genus classification, marine and brackish flags, and citation. /v1/classification?id=137102 returns the complete taxonomic tree from Biota down to the taxon, rank by rank. /v1/vernaculars?id=137102 returns the common names with their language. Get an AphiaID from /v1/search, then look up its details, tree or common names. Ideal for marine biology, fisheries science, ecology, aquaculture and biodiversity-data harmonisation. Data from WoRMS (CC BY). This is authoritative marine taxonomy and nomenclature — distinct from species-occurrence/biodiversity databases (such as GBIF) and from sequence or genome databases.

api.oanor.com/worms-api