Apparent oxygen utilisation

Apparent oxygen utilisation

In freshwater or marine systems apparent oxygen utilisation (AOU) is the difference between the measured dissolved oxygen concentration and its equilibrium saturation concentration in water with the same physical and chemical properties [Garcia, H.E., Locarnini, R.A., Boyer, T.P. and Antonov, J.I. (2006). [ World Ocean Atlas 2005 Volume 3: Dissolved Oxygen, Apparent Oxygen Utilization, and Oxygen Saturation.] S. Levitus, Ed. NOAA Atlas NESDIS 63, U.S. Government Printing Office, Washington, D.C., 342 pp.] . Such differences typically occur when biological activity acts to change the ambient concentration of oxygen. For example, primary production liberates oxygen and increases its concentration, while respiration consumes it and decreases its concentration.

Consequently, the AOU of a water sample represents the sum of the biological activity that the sample has experienced since it was last in equilibrium with the atmosphere. In shallow water systems (e.g. lakes), the full water column is generally in close contact with the atmosphere, so oxygen concentrations are typically close to saturation. In deep water systems (e.g. oceans), water can be out of contact with the atmosphere for extremely long periods of time (years, decades, centuries) and large AOU values are possible.

ee also

* Biological pump
* Eutrophication
* Hypoxia
* Remineralisation
* World Ocean Atlas


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Dioxygen in biological reactions — Further information: Geological history of oxygen Dioxygen (O2) plays an important role in the energy metabolism of living organisms. Free oxygen is produced in the biosphere through photolysis (light driven oxidation and splitting) of water… …   Wikipedia

  • Oxygenation (environmental) — See also: oxygen saturation and water aeration Environmental oxygenation can be important to the sustainability of a particular ecosystem. Insufficient oxygen (environmental hypoxia) may occur in bodies of water such as ponds and rivers,… …   Wikipedia

  • World Ocean Atlas — The World Ocean Atlas (WOA) is a data product of the Ocean Climate Laboratory of the National Oceanographic Data Center (U.S.). The WOA consists of a climatology of fields of in situ ocean properties for the World Ocean. It was first produced in… …   Wikipedia

  • AOU — may refer to either of the following: * American Ornithologists Union * Arab Open University, a private, not for profit university with branches in several Arab countries * Apparent oxygen utilisation * Arcade Operators Union Amusement Expo …   Wikipedia

  • International Space Station — ISS redirects here. For other uses, see ISS (disambiguation). International Space Station …   Wikipedia

  • Terre — Pour les articles homonymes, voir Terre (homonymie). Terre …   Wikipédia en Français

  • Gasification — This article is about the process. For the water carbonator, see Gasogene. For the automobile device, see Wood gas generator. Sustainable energy …   Wikipedia

  • Station spatiale internationale — Pour les articles homonymes, voir ISS. Station spatiale internationale Assemblage …   Wikipédia en Français

  • Naine Blanche — Traduction terminée White dwarf → …   Wikipédia en Français

  • Naines blanches — Naine blanche Traduction terminée White dwarf → …   Wikipédia en Français