The following are considered ocean essential climate variables (ECVs) by the Ocean Observations Panel for Climate (OOPC) that are currently feasible with current observational systems .

Ocean climate variables

Atmosphere surface

* Air

Temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

Precipitation (meteorology) In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hai ...

* Evaporation *

Air Pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars ...

sea level pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, 7 ...

(SLP) * Surface radiative fluxes * Surface thermodynamic fluxes * Wind speed and direction * Surface wind stress *

Water vapor (99.9839 °C) , - , Boiling point , , - , specific gas constant , 461.5 J/( kg·K) , - , Heat of vaporization , 2.27 MJ/kg , - , Heat capacity , 1.864 kJ/(kg·K) Water vapor, water vapour or aqueous vapor is the gaseous p ...

Ocean surface

Sea surface temperature Sea surface temperature (SST), or ocean surface temperature, is the ocean temperature close to the surface. The exact meaning of ''surface'' varies according to the measurement method used, but it is between and below the sea surface. Air mas ...

(SST) * Sea surface salinity (SSS) *

Sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardise ...

* Sea state * Sea ice *

Ocean current An ocean current is a continuous, directed movement of sea water generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours ...

Ocean color Ocean color is the branch of ocean optics that specifically studies the color of the water and information that can be gained from looking at variations in color. The color of the ocean, while mainly blue, actually varies from blue to green or ...

(for biological activity) * Carbon dioxide partial pressure (

pCO2 ''p''CO2, pCO2, or P_\ceis the partial pressure of carbon dioxide (CO2), often used in reference to blood but also used in meteorology, climate science, oceanography, and limnology to describe the fractional pressure of CO2 as a function of its ...

)

Ocean subsurface

Backscatter In physics, backscatter (or backscattering) is the reflection of waves, particles, or signals back to the direction from which they came. It is usually a diffuse reflection due to scattering, as opposed to specular reflection as from a mirror, a ...

Carbon Dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

* Chlorophyll *

Conductivity Conductivity may refer to: *Electrical conductivity, a measure of a material's ability to conduct an electric current **Conductivity (electrolytic), the electrical conductivity of an electrolyte in solution ** Ionic conductivity (solid state), ele ...

Density Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...

Iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

* Irradiance *

Nutrients A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excre ...

** Nitrate *

Methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Ea ...

** Single Point ** Water Column * Ocean tracers *

Oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

* Phytoplankton * Salinity *

Sigma-T Sigma-t is a quantity used in oceanography to measure the density of seawater at a given temperature. σT is defined as ρ(S,T)-1000 kg m−3, where ρ(S,T) is the density of a sample of seawater at temperature T and salinity S, measured in Ki ...

Sound Velocity The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. At , the speed of sound in air is about , or one kilometre in or one mile in . It depends strongly on temperature as wel ...

Turbidity Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids ...

Ocean observation sources

Satellite

There is a composite network of satellites that generate observations. These include:

''In situ''

There is a composite network of in situ observations. These include:

Subsurface

There is a composite network of subsurface observations. These include:

Accuracy of measurements

The quality of ''in situ'' measurements is non-uniform across space, time and platforms. Different platforms employ a large variety of sensors, which operate in a wide range of often hostile environments and use different measurement protocols. Occasionally, buoys are left unattended for extended periods of time, while ships may involve a certain amount of the human-related impacts in data collection and transmission. Therefore, quality control is necessary before in situ data can be further used in scientific research or other applications. This is an example of quality control and monitoring of sea surface temperatures measured by ships and buoys, the iQuam system developed at NOAA/NESDIS/STAR, where statistics show the quality of ''in situ'' measurements of sea surface temperatures. One of the problems facing real-time ocean observatories is the ability to provide a fast and accurate assessment of the data quality. Ocean Networks Canada is in the process of implementing real-time quality control on incoming data. For scalar data, the aim is to meet the guidelines of the Quality Assurance of Real Time Oceanographic Data (QARTOD) group. QARTOD is a US organization tasked with identifying issues involved with incoming real-time data from the U.S Integrated Ocean Observing System (IOOS). A large portion of their agenda is to create guidelines for how the quality of real-time data is to be determined and reported to the scientific community. Real-time data quality testing at Ocean Networks Canada includes tests designed to catch instrument failures and major spikes or data dropouts before the data is made available to the user. Real-time quality tests include meeting instrument manufacturer's standards and overall observatory/site ranges determined from previous data. Due to the positioning of some instrument platforms in highly productive areas, we have also designed dual-sensor tests e.g. for some conductivity sensors. The quality control testing is split into 3 separate categories. The first category is in real-time and tests the data before the data are parsed into the database. The second category is delayed-mode testing where archived data are subject to testing after a certain period of time. The third category is manual quality control by an Ocean Networks Canada data expert.

Historical data available

OceanSITES manages a set of links to various sources of available ocean data, including: the Hawaiian Ocean Timeseries (HOT), the JAMSTEC Kuroshio Extension Observatory (JKEO), Line W monitoring the North Atlantic's deep western boundary current, and others. This site includes links to the ARGO Float Data, The Data Library and Archives (DLA), the Falmouth Monthly Climate Reports, Martha's Vineyard Coastal Observatory, the Multibeam Archive, the Seafloor Data and Observation Visualization Environment (SeaDOVE): A Web-served GIS Database of Multi-scalar Seafloor Data, Seafloor Sediments Data Collection, the Upper Ocean Mooring Data Archive, the U.S. GLOBEC Data System, U.S. JGOFS Data System, and the WHOI Ship Data-Grabber System. There are a variety of data sets in a data library listed at Columbia University: This library includes: * LEVITUS94 is the World Ocean Atlas as of 1994, an atlas of objectively analyzed fields of major ocean parameters at the annual, seasonal, and monthly time scales. It is superseded by WOA98. * NOAA NODC WOA98 is the World Ocean Atlas as of 1998, an atlas of objectively analyzed fields of major ocean parameters at monthly, seasonal, and annual time scales. Superseded by WOA01. * NOAA NODC WOA01 is the World Ocean Atlas 2001, an atlas of objectively analyzed fields of major ocean parameters at monthly, seasonal, and annual time scales. Replaced by WOA05. * NOAA NODC WOA05 is the World Ocean Atlas 2005, an atlas of objectively analyzed fields of major ocean parameters at monthly, seasonal, and annual time scales. In situ observations spanning from the early 1700s to present are available from the International Comprehensive Ocean Atmosphere Data Set (ICOADS). This data set includes observations of a number of the surface ocean and atmospheric variables from ships, moored and drifting buoys and C-MAN stations. In 2006,

Ocean Networks Canada Ocean Networks Canada is a University of Victoria initiative that operates the NEPTUNE and VENUS cabled ocean observatories in the northeast Pacific Ocean and the Salish Sea. Additionally, Ocean Networks Canada operates smaller community-based ob ...

began collecting high-resolution in-situ measurements from the seafloor in

Saanich Inlet , image = Saanich Inlet from Gowlland Tod Provincial Park, Vancouver Island, Canada 13.jpg , image_size = 260px , caption = Saanich Inlet from Gowlland Tod Provincial Park , image_bathymetry = , caption_bathymetry = , location = Northwest o ...

, near

Victoria, British Columbia Victoria is the capital city of the Canadian province of British Columbia, on the southern tip of Vancouver Island off Canada's Pacific coast. The city has a population of 91,867, and the Greater Victoria area has a population of 397,237. The ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

. Monitoring sites were later extended to the Strait of Georgia and 5 locations off the West coast of

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian province of British Columbia. The island is in length, in width at its widest point, and in total area, while are of land. The island is the largest by ...

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

. All historical measurements are freely available via Ocean Networks Canada's data portal, Oceans 2.0.

Future developments

Areas requiring research and development * Satellite observations with higher resolution and accuracy and more spectral bands from geostationary satellites * improved capability for ocean color observations in coastal and turbid waters * improved interpretation of sea-ice data from satellites * satellite measurement of salinity * Observing system evaluation and design, including improvements in air-sea flux parameterizations. * Improvements in ocean platforms, including increased capabilities for Argo floats * improved glider technology and mooring technology. * New development in ocean sensors and systems, including improved bio-fouling protection, autonomous water sampling systems, optical and acoustic systems, airborne variable sensors, and two-way, low-cost, low-power telecommunications. * New and improved capability to measure biogeochemical variables, nutrients, and dissolved oxygen and carbon dioxide, as well as to identify organisms. * Improved instruments, including near-surface current meters, in-water radiometers, sensors for air-sea interface variables and turbulent fluxes, and VOS sensor systems. The future of oceanic observation systems: * Guided unmanned underwater vehicles

Organizations

* GOOS (The Global Ocean Observing System) * GCOS (

Global Climate Observing System The Global Climate Observing System (GCOS) was established in 1992 as an outcome of the Second World Climate Conference, to ensure that the observations and information needed to address climate-related issues are obtained and made available to ...

) * IOOS (

Integrated Ocean Observing System The Integrated Ocean Observing SystemIOOS is an organization of systems that routinely and continuously provides quality controlled data and information on current and future states of the oceans and Great Lakes from the global scale of ocean basi ...

) * Argo * GODAE ( Global Ocean Data Experiment) *

* OOPC ( Ocean Observations Panel for Climate) * OOI (

Ocean Observatories Initiative The Ocean Observatories Initiative (OOI) is a National Science Foundation (NSF)br>Major Research Facilitycomposed of a network of science-driven ocean observing platforms and sensors ( ocean observatories) in the Atlantic and Pacific Oceans. Th ...

) * FixO
(Fixed-Point Open Ocean Observatories)
re
FixO3
official webpage

References

{{physical oceanography, expanded=none Oceanography Earth observation