World Ocean Circulation Experiment

The World Ocean Circulation Experiment (WOCE) was a component of the international World Climate Research Program, and aimed to establish the role of the World Ocean in the Earth's climate system. WOCE's field phase ran between 1990 and 1998, and was followed by an analysis and modeling phase that ran until 2002.[1] When the WOCE was conceived, there were three main motivations for its creation. The first of these is the inadequate coverage of the World Ocean, specifically in the Southern Hemisphere. Data was also much more sparse during the winter months than the summer months, and there was—and still to some extent—a critical need for data covering all seasons. Secondly, the data that did exist was not initially collected for studying ocean circulation and was not well suited for model comparison. Lastly, there were concerns involving the accuracy and reliability of some measurements. The WOCE was meant to address these problems by providing new data collected in ways designed to “meet the needs of global circulation models for climate prediction.” [2]

Goals

Two major goals were set for the campaign.[1]

1. Develop ocean models that can be used in climate models and collect the data necessary for testing them. Specifically, understand:

  • Large scale fluxes of heat and fresh water
  • Dynamical balance of World Ocean circulation
  • Components of ocean variability on months to years
  • The rates and nature of formation, ventilation and circulation of water masses that influence the climate system on time scales from ten to one hundred years [3]

In order to achieve Goal 1, the WCRP outlined and established Core Projects that would receive priority. The first of these was the “Global Description” project, which was meant to obtain data on the circulation of heat, fresh water and chemicals, as well as the statistics of eddies. The second project—“Southern Ocean”—placed particular emphasis on studying the Antarctic Circumpolar Current and the Southern Ocean’s interaction with the World Ocean. The third and final Core Project serving goal one was the “Gyre Dynamics Experiment.” The second and third of these focuses are designed specifically to address the ocean’s role in decadal climate changes. Initial planning of the WOCE states that achievement of Goal 1 would involve “strong interaction between modeling and field activities,” which are described further below.

2. Find the representativeness of the dataset for long-term behavior and find methods for determining long-term changes in ocean currents. Specifically:

  • Determine representative of specific WOCE data sets
  • Identify those oceanographic parameters, indices and fields that are essential for continuing measurements in a climate observing system on decadal time scales
  • Develop cost effective techniques suitable for deployment in an ongoing climate observing system[3]

Modeling

Models in WOCE were used for both experimental design and data analysis. Models with use of data can incorporate various properties, including thermal wind balance, maintenance of the barotropic vorticity budget, and conservation of heat, fresh water, or mass. Measurements useful for these parameters are heat, fresh water or tracer concentration; current, surface fluxes of heat and fresh water; sea surface elevation.[3]

Both inverse modeling and data assimilation were employed during WOCE. Inverse modeling is the fitting of data using a numerical least squares or maximum likelihood fitting procedure. The data assimilation technique requires data to be compared with an initial integration of a model. The model is then progressed in time using new data and repeating the process.[3]

The success of these methods requires sufficient data to fully constrain the model, hence the need for a comprehensive field program.

Field Program

Goals for the WOCE Field Program were as follows.[1]

  • The experiment will be global in nature and the major observational components will be deployed in all oceans.
  • The requirement of simultaneity of measurements will be imposed only where absolutely essential.
  • The flexibility inherent in the existing arrangements for cooperative research in the worldwide oceanographic (and meteorological) community will be exploited as far as possible.

Major elements of the WOCE Field Program [3]

  • Satellite Altimetry: plans built around the availability of ERS–1 and ERS–2 (European), TOPEX/POSEIDON (US/French) to study fields of surface forcing and oceanic surface topography [2]
  • Hydrography: high quality conductivity-temperature-pressure profilers as well as free-fall instruments to provide a climatological temperature-salinity database [2]
  • Geochemical Tracers: using chemical information (such as radioactive decay and atmospheric history) of passive compounds to study the formation rates and transport of water masses on climatological timescales
  • Ocean Surface Fluxes: using in-situ and satellite measurements to quantify fluxes of heat, water and momentum (necessary for modeling thermohaline and wind-driven circulation)
  • Satellite Winds: using surface buoys, Voluntary Observing Ships (VOS) and satellite microwave scatterometer systems to measure the surface wind field
  • Surface Meteorological Observations from VOS: improvement of sampling and accuracy in surface meteorological measurements, as well increasing area coverage
  • Upper Ocean Observations from Merchant Ships-of-Opportunity: expendable bathythermograph (XBT) sampling lines to study changes in heat content of the upper ocean
  • In-Situ Sea Level Measurements: upgrading and installing new sea-level gauges to calibrate altimetry measurements
  • Drifting Buoys and Floats: surface drifting buoys provide measurements such as sea level pressure, sea-surface temperature, humidity, precipitation, surface salinity, and near-surface and mid-depth currents
  • Moored instrumentation: provides detailed temporal information at a number of sites and depths

Resulting Conclusions

This list, though not comprehensive, outlines a sampling of the most highly cited articles and books resulting from the WOCE.

  • Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data
   A. Ganachaud & C. Wunsch
   Nature, November 2000
  • Ocean Circulation and Climate, Observing and Modelling the Global Ocean, 1st Edition
   Eds. Gerold Siedler, John Gould & John Church
   Academic Press, 736pp. (International Geophysics Series 77) 2001
  • Volume, heat, and freshwater transports of the global ocean circulation 1993–2000, estimated from a general circulation model constrained by World Ocean Circulation Experiment (WOCE) data
   D. Stammer, C. Wunsch, R. Giering, C. Eckert, P. Heimbach, J. Marotzke, A. Adcroft, C. N. Hill, J. Marshall
   Journal of Geophysical Research, January 2003
  • Large-scale mass transports, water mass formation, and diffusivities estimated from World Ocean Circulation Experiment (WOCE) hydrographic data
   A. Ganachaud
   Journal of Geophysical Research, July 2003
  • Oceanic nutrient and oxygen transports and bounds on export production during the World Ocean Circulation Experiment
   A. Ganachaud, Carl Wunsch
   Global Biogeochemical Cycles, October 2002
  • Revisiting the South Pacific subtropical circulation: A synthesis of World Ocean Circulation Experiment observations along 32°S
   S. E. Wijffels, J. M. Toole, R. Davis
   Journal of Geophysical Research, September 2012

See also

External links

References

  1. ^ a b c Ocean Circulation and Climate: World Ocean Circulation Experiment. Retrieved 7 December 2013.
  2. ^ a b c The World Ocean Circulation Experiment. J.D. Woods. Retrieved 7 December 2013.
  3. ^ a b c d e Scientific Plan for the World Ocean Circulation Experiment. J.D. Woods. Retrieved 7 December 2013.
Argos system

Argos is a satellite-based system which collects, processes and disseminates environmental data from fixed and mobile platforms worldwide. What makes Argos unique is the ability to clearly geographically locate the source of the data anywhere on the Earth utilizing the Doppler effect.

Argos was established in 1978 and since that time, it has provided data to environmental research and protection communities that, in many cases, was otherwise unobtainable. The system is fully proven and highly reliable. Many remote automatic weather stations report via Argos. Argos is a key component of many global research programs including: Tropical Ocean-Global Atmosphere program (TOGA), Tagging of Pacific Pelagics (TOPP), World Ocean Circulation Experiment (WOCE), Argo, and others. There are currently 22,000 active transmitters, 8,000 of which are used in animal tracking, and over 100 countries utilize the Argos system.

Since the late 1980s Argos transmitters have routinely been deployed on a large number of marine mammals and sea turtles and it continues to serve as the most important tool for tracking long distance movements of both coastal and oceanic species. Through upload of data from, for example, pressure transducers, it has also been possible to obtain a wealth of knowledge about dive and foraging behavior from unrestrained animals in the wild.

Argos was developed under a Memorandum of Understanding (MOU) between the Centre National d'Etudes Spatiales (CNES, the French space agency), the National Aeronautics and Space Administration (NASA, USA) and the National Oceanic and Atmospheric Administration (NOAA, USA).

The system utilizes both ground and satellite-based resources to accomplish its mission. These include:

instruments carried aboard the NOAA polar orbiting environmental satellites (POES), the EUMETSAT MetOp satellites, and ISRO satellites,

receiving stations around the world,

and major processing facilities in Toulouse in France and Lanham, Maryland in the United States.This fully integrated system works to conveniently locate and deliver data from the most remote platforms to the user's desktop, often in near real-time.

Argos is operated by CLS/Argos, based in Toulouse, France, and its U.S. subsidiary, CLS America. Since June 2019, a new subsidiary named Kinéis has taken over operations and plans to launch a constellation of 16U CubeSats in 2022.

CLIVAR

CLIVAR (climate variability and predictability) is a component of the World Climate Research Programme. Its purpose is to describe and understand climate variability and predictability on seasonal to centennial time-scales, identify the physical processes responsible for climate change and develop modeling and predictive capabilities for climate modelling.

Centre for Maritime Research and Experimentation

Previously known as NATO Undersea Research Centre (NURC), the Centre for Maritime Research and Experimentation (CMRE) is a scientific research and experimentation NATO facility that organizes and conducts scientific research and technology development, centered on the maritime domain, to address defense and security needs of the Alliance. It is an executive body of NATO's Science and Technology Organization (STO).

Geochemical Ocean Sections Study

The Geochemical Ocean Sections Study (GEOSECS) was a global survey of the three-dimensional distributions of chemical, isotopic, and radiochemical tracers in the ocean. A key objective was to investigate the deep thermohaline circulation of the ocean, using chemical tracers, including radiotracers, to establish the pathways taken by this.Expeditions undertaken during GEOSECS took place in the Atlantic Ocean from July 1972 to May 1973, in the Pacific Ocean from August 1973 to June 1974, and in the Indian Ocean from December 1977 to March 1978.Measurements included those of physical oceanographic quantities such as temperature, salinity, pressure and density, chemical / biological quantities such as total inorganic carbon, alkalinity, nitrate, phosphate, silicic acid, oxygen and apparent oxygen utilisation (AOU), and radiochemical / isotopic quantities such as carbon-13, carbon-14 and tritium.

Gerold Siedler

Gerold Siedler (born August 16, 1933) is a German physical oceanographer. He is professor emeritus at the Christian-Albrechts University of Kiel and at the GEOMAR Helmholtz Centre for Ocean Research Kiel.

Global Ocean Data Analysis Project

The Global Ocean Data Analysis Project (GLODAP) is a synthesis project bringing together oceanographic data, featuring two major releases as of 2018. The central goal of GLODAP is to generate a global climatology of the World Ocean's carbon cycle for use in studies of both its natural and anthropogenically-forced states. GLODAP is funded by the National Oceanic and Atmospheric Administration, the U.S. Department of Energy, and the National Science Foundation.

The first GLODAP release (v1.1) was produced from data collected during the 1990s by research cruises on the World Ocean Circulation Experiment, Joint Global Ocean Flux Study and Ocean-Atmosphere Exchange Study programmes. The second GLODAP release (v2) extended the first using data from cruises from 2000–2013. The data are available both as individual "bottle data" from sample sites, and as interpolated fields on a standard longitude, latitude, depth grid.

Global Ocean Ecosystem Dynamics

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The aim of GLOBEC is to advance our understanding of the structure and functioning of the global ocean ecosystem, its major subsystems, and its response to physical forcing so that a capability can be developed to forecast the responses of the marine ecosystem to global change.

Indian Monsoon Current

The Indian Monsoon Current refers to the seasonally varying ocean current regime found in the tropical regions of the northern Indian Ocean. During winter, the flow of the upper ocean is directed westward from near the Indonesian Archipelago to the Arabian Sea. During the summer, the direction reverses, with eastward flow extending from Somalia into the Bay of Bengal. These variations are due to changes in the wind stress associated with the Indian monsoon. The seasonally reversing open ocean currents that pass south of India are referred to as the Winter Monsoon Current and the Summer Monsoon Current (alternately, the Northeast Monsoon Current and the Southwest Monsoon Current). The Somali Current, which is strongly linked to the Indian monsoon, is also discussed in this article.

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Professor John David Woods, CBE (born 1939) is a British oceanographer.He studied physics at Imperial College, London (1958–66), after which he was appointed principal research fellow at the Meteorological Office (1966–72), while leading the RN Operation Thermocline in which he pioneered underwater flow visualisation. Later he joined NERC as Director of Marine and Atmospheric Science (1986-1994), where he created the National Oceanography Centre at Southampton. He held professorships at Southampton University (1972–77), Kiel University (1977-86) and Imperial College London (1994- ), carrying out research into the seasonal boundary layer of the ocean and plankton ecosystem models, and modelling global container freight.Woods has served on a number of international project committees, including GARP (Global Atmospheric Research Programme), WCRP (World Climate Research Programme0, IGBP (International GeoSphere-Biosphere Programme), EuroGOOS (European Global Ocean Observing System). He was co-chairman of the World Ocean Circulation Experiment. He was a lead author of the first report of the Intergovernmental Panel on Climate Change (IPCC), an organisation which was later awarded the 2007 Nobel Peace Prize jointly with Al Gore.He is now (2015) Emeritus Professor of Oceanography & Complex Systems in the Faculty of Engineering, Department of Earth Science & Engineering, Imperial College London. He is Adjunct Fellow of Linacre College, University of Oxford (1994- ), and Emeritus Researcher of the CNR (Italian National Research Council).

Lynne Talley

Lynne Talley (born May 18, 1954) is an American physical oceanographer.

Talley is Professor of Physical Oceanography at Scripps Institution of Oceanography and has spent many months on research ships serving as chief scientist and collecting oceanographic hydrography data. She has a strong record of continuous participation in international steering groups and oversight committees for collection and use of oceanographic data. Talley is a Fellow of the American Meteorological Society, the American Geophysical Union, The Oceanography Society, the American Association for the Advancement of Science, and the American Academy of Arts and Sciences.

NOAAS Discoverer (R 102)

NOAAS Discoverer (R 102), originally USC&GS Discoverer (OSS 02), was an American Oceanographer-class oceanographic research vessel in service in the United States Coast and Geodetic Survey from 1966 to 1970 and in the National Oceanic and Atmospheric Administration (NOAA) from 1970 to 1996.

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Ocean Data View includes also options that permit to perform objective analysis thanks to the add-on DIVA software.

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Physical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters.

Physical oceanography is one of several sub-domains into which oceanography is divided. Others include biological, chemical and geological oceanography.

Physical oceanography may be subdivided into descriptive and dynamical physical oceanography.Descriptive physical oceanography seeks to research the ocean through observations and complex numerical models, which describe the fluid motions as precisely as possible.

Dynamical physical oceanography focuses primarily upon the processes that govern the motion of fluids with emphasis upon theoretical research and numerical models. These are part of the large field of Geophysical Fluid Dynamics (GFD) that is shared together with meteorology. GFD is a sub field of Fluid dynamics describing flows occurring on spatial and temporal scales that are greatly influenced by the Coriolis force.

Undersea mountain range

Undersea mountain ranges are mountain ranges that are mostly or entirely underwater, and specifically under the surface of an ocean. If originated from current tectonic forces, they are often referred to as a mid-ocean ridge. In contrast, if formed by past above-water volcanism, they are known as a seamount chain. The largest and best known undersea mountain range is a mid-ocean ridge, the Mid-Atlantic Ridge. It has been observed that, "similar to those on land, the undersea mountain ranges are the loci of frequent volcanic and earthquake activity".

WOCE

WOCE may mean:

World Ocean Circulation Experiment

WOCE (FM) 101.9 in Ringgold, Georgia, USA

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The wave base, in physical oceanography, is the maximum depth at which a water wave's passage causes significant water motion. For water depths deeper than the wave base, bottom sediments and the seafloor are no longer stirred by the wave motion above.

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The World Ocean Database represents the world’s largest collection of ocean profile-plankton data available internationally without restriction. Data comes from the: (a) Sixty-five National Oceanographic Data Centers and nine Designated National Agencies (DNAs) (in Croatia, Finland, Georgia, Malaysia, Romania, Senegal, Sweden, Tanzania, and Ukraine), (b) International Ocean Observing Projects such as the completed World Ocean Circulation Experiment (WOCE) and Joint Global Ocean Flux Study (JGOFS), as well as currently active programs such as CLIVAR and Argo, (c) International Ocean Data Management Projects such as the IOC/IODE Global Oceanographic Data Archaeology and Rescue Project (GODAR), and (d) Real-time Ocean Observing Systems such as the IOC/IODE Global Temperature-Salinity Profile Project (GTSPP). All ocean data acquired by WDC Silver Spring – USA are considered as part of the WDC archive and are freely available as public domain data.

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