Argo world 

News Archive
August 23, 2016 CSIRO will host the AST-18 meeting the week of 13 - 17 March, 2016
Details and registration to follow
August 20, 2016 Meeting report posted for the AST-17 meeting
August 17, 2016 New install available for Global Marine Argo Atlas
July 29, 2016 Argonautics 15 is published
July 8, 2016 Argo bibliography, Argo in press and Argo thesis list updated.
Inform of changes.
March 1, 2016 NMDIS will host the 17th Argo Data Management Team meeting the week of 26 September 2016 in Tianjin, China
January 27, 2016 Fifteen years of ocean observations with the global Argo array
Nature Climate Change review paper on Argo
October 28, 2015 It's official - 309 Argo papers published in 299 days in 2015!
September 10, 2015 Deep Argo Implementation Workshop Report is published
July 16, 2015 An Argo float covers the "State of the Climate in 2014" report published by the Bulletin of the American Meteorological Society
February 12, 2015 Technical note from Sea-Bird on Druck vs. Kistler pressure sensors
June 13, 2014 Introduction to the new V3.0 & 3.1 profile files
Introduction to the new V3.0 & 3.1 meta files
June 7, 2013 Introduction to the new trajectory 3.0 files

What is Argo?

Argo is a global array of more than 3,000 free-drifting profiling floats that measures thetemperature 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.

Positions of the floats that have delivered data within the last 30 days :

Maps displaying statistics about the Argo array, including its extensions into high latitudes and marginal seas, bio-geochemical sensors, communication systems, float type, etc., can be found in the map room on the Argo Information Centre website.

Why do we need Argo?

We are increasingly concerned about global change and its regional impacts. Sea level is rising at an accelerating rate of 3 mm/year, Arctic sea ice cover is shrinking and high latitude areas are warming rapidly. Extreme weather events cause loss of life and enormous burdens on the insurance industry. Globally, 8 of the 10 warmest years since 1860, when instrumental records began, were in the past decade.

These effects are caused by a mixture of long-term climate change and natural variability. Their impacts are in some cases beneficial (lengthened growing seasons, opening of Arctic shipping routes) and in others adverse (increased coastal flooding, severe droughts, more extreme and frequent heat waves and weather events such as severe tropical cyclones).

Understanding (and eventually predicting) changes in both the atmosphere and ocean are needed to guide international actions, to optimize governments' policies and to shape industrial strategies. To make those predictions we need improved models of climate and of the entire earth system (including socio-economic factors).

Lack of sustained observations of the atmosphere, oceans and land have hindered the development and validation of climate models. An example comes from a recent analysis which concluded that the currents transporting heat northwards in the Atlantic and influencing western European climate had weakened by 30% in the past decade. This result had to be based on just five research measurements spread over 40 years. Was this change part of a trend that might lead to a major change in the Atlantic circulation, or due to natural variability that will reverse in the future, or is it an artifact of the limited observations?

In 1999, to combat this lack of data, an innovative step was taken by scientists to greatly improve the collection of observations inside the ocean through increased sampling of old and new quantities and increased coverage in terms of time and area.

That step was Argo.

Argo animationargo.avi is a float animation that explains the purpose and method of Argo.

Where is Argo now?

Argo deployments began in 2000 and by November 2007 the millionth profile was collected. Today, even with more than 3600 active floats, there are still some areas of the ocean that are over-populated while others have gaps that need to be filled with additional floats. Today's tally of floats is shown in the figure above and additional float statistics can be found here. To maintain the Argo array, national programs need to provide about 800 floats per year.

In addition to the core Argo array described above, there are several Argo extensions that are in various stages of development and implementation. These include enhanced spatial coverage in marginal seas, high latitudes, boundary current regions and equatorial regions, extended depth coverage to the ocean bottom, and continued increases in bio-geochemical sensor additions to floats.

Besides float deployment, Argo has worked hard to develop two separate data streams: real time and delayed mode. A real time data delivery and quality control system has been established that delivers 90% of profiles to users via two global data centers (GDACs) within 24 hours. A delayed mode quality control system (DMQC) has been established and 65% of all eligible profiles have had DMQC applied.

Float reliability has improved almost every year and the float lifetime has been extended. Argo has developed a large user community in universities, government labs and meteorological/climate analysis/forecasting centers. The need for global Argo observations will continue indefinitely into the future, though the technologies and design of the array will evolve as better instruments are built, models are improved, and more is learned about ocean variability.

Who Collaborates with Argo?

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).