Current Status of Argo
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 latest picture of the
Brief History of Argo
The name Argo was chosen to emphasize
the strong complementary relationship of the global float
satellite altimeter mission. In Greek mythology Jason sailed in a ship called "Argo" to capture
the golden fleece.
Together the Argo and Jason data sets will be assimilated into computer models developed by project GODAE
(Global Ocean Data Assimilation Experiment) that will allow a test of our ability to forecast ocean climate.
For the first time, the physical state
of the upper ocean is being systematically measured and the data
assimilated in near real-time into computer models.
Argo builds on other upper-ocean ocean observing
coverage in space an time, their depth range and
accuracy, and enhancing them through the addition of
velocity measurements. Argo is not confined to major shipping routes which can vary with season
as the other upper-ocean observing networks are. Instead, the global array of 3,000 floats will be distributed
roughly every 3 degrees (300km).
An Argo float being deployed from a research ship. |
will provide a quantitative description of the changing state of the
upper ocean and the patterns of ocean climate variability from months
to decades, including heat and
freshwater storage and transport.
data will enhance the value of the Jason altimeter through measurement of subsurface temperature, salinity, and velocity,
coverage and resolution to permit interpretation of altimetric
sea surface height
- Argo data will be used for initializing ocean and
forecast models, for data assimilation and for model testing.
- A primary focus of Argo is to
document seasonal to decadal climate variability and to aid
understanding of its predictability. A wide range of applications for high-quality global ocean analyses
An Argo profile from the subtropical North Pacific
(20.25N 121.4W, May 15 2004). This shows interleaving in the
Argo Design and Data
The design of the Argo network is
based on experience from the present observing system, on recent
knowledge of variability from the TOPEX/Poseidon altimeter, and on
the requirements for climate and
The final array of 3000 floats will
provide 100,000 temperature/salinity (T/S) profiles and velocity measurements per year
distributed over the global oceans at an average 3-degree
spacing. Floats will cycle to
2000m depth devery 10 days, with 4-5 year lifetimes for individual instruments. All data collected by Argo floats are
publically available in near real-time via the Global Data Assembly Centers (GDACs) in Brest, France and
Monterey, California after an automated
quality control (QC), and in scientifically quality controlled form, delayed mode data, via the GDACs within six months of collection.