Data on the Temperature, Salinity & Velocity of the Upper Ocean
Online — Argo is a global array of more than 3,000 free-drifting profiling floats that measures the temperature and salinity of the upper 2000 m of the ocean.
This allows, for the first time, continuous monitoring of the temperature, salinity, and velocity of the upper ocean, with all data being relayed and made publicly available within hours after collection.
Argo is a major contributor to the WCRP ‘s Climate Variability and Predictability Experiment (CLIVAR) project and to the Global Ocean Data Assimilation Experiment (GODAE). The Argo array is part of the Global Climate Observing System/Global Ocean Observing System GCOS /GOOS).
Given the expanding size of the Argo data system, there are other ways to access Argo data besides downloading the netCDF files from the GDACs.
There is also a beginner’s guide to Argo data.
In addition to the real-time data stream, Argo has the potential, after careful data assessment, to provide salinity/temperature/pressure profiles that approach ship-based data accuracy.
In general there is no possibility of carrying out calibration checks on a float’s sensors after it has left the laboratory or has been launched by a research ship that might make a nearby CTD cast.
One means of adjusting salinities is to look at deviations of the float data from a stable, deep temperature/salinity climatology [Owens et al., 2009, Bohme et al., 2005, Wong et al., 2003], or to compare profiles from floats that coincide in space and time.
The OW method (Owens et al., 2009) has been adopted by Argo as its standard means of delayed mode data quality control. The delayed-mode quality control is the responsibility of researchers in each country in collaboration with the appropriate national data center.
It has been recommended that delayed mode data inspection is carried out on a 1 year long record so that sudden jumps in calibration may be distinguished from long term drift or water mass property changes. This imposes a minimum 6 month delay on the availability of delayed mode data.
This system was adopted in 2004 and is now being applied to Argo data. These delayed-mode data are currently available from the GDACs. To learn more about the data management of Argo and how to use the Argo data effectively, visit the Argo Data Management Website.
An additional phase of Argo data management occurs at a regional level at the Argo Regional Centers (ARCs). This enables the accumulation of consistent regional data sets and the production of Argo based products. To learn more about the Argo Regional Centers, go to ARC page.
The broad-scale global array of temperature/salinity profiling floats, known as Argo, has already grown to be a major component of the ocean observing system. Argo is a standard to which other developing ocean observing systems can look to. For example, Argo offers ideas on various topics such as how to collaborate internationally, how to develop a data management system and how to change the way scientists think about collecting data. Deployments began in 2000 and continue today at the rate of about 800 per year.
The array is made up of 30 different countries’ contributions that range from a single float, to the U.S. contribution, which is roughly 50% of the global array. To see how many floats are deployed by each country, look at the 2007 Commitments Table
Funding mechanisms differ widely between counties and involve over 50 research and operational agencies. Each national program has its own priorities but all nations subscribe to the goal of building the global array and to Argo’s open data policy.
Management of Argo
The project is overseen by an International Argo Steering Team and a Data Management Team that are comprised of representataives of float-providing countries. The array’s growth is monitored by the Technical Coordinator at the Argo Information Center (AIC) that is located in Toulouse as part of the JCOMMOPS monitoring and co-ordinating system for operational ocean observations. There is also an Argo Director.
A primary function of the AIC is to implement resolution XX-6 of the Intergovernmental Ocean ographic Commission of UNESCO. This resolution states that : “Concerned coastal states must be informed in advance, through appropriate channels, of all deployments of profiling floats which might drift into waters under their jurisdiction, indicating the exact location of such deployments.”
Thus the AIC operates a formal deployment notification process and some countries have given formal concurrence for the operation of Argo floats within their Exclusive Economic Zone (EEZ).
Argo Project Office
Argo Information Center
BP70, Plouzane – FRANCE 29280