Argo Robotic Instrument Network Now Covers Most Of
International network reaches 1,500th float deployment—halfway
to full array
By Mario Aguilera
have crossed an important threshold in an international effort
to deploy a global network of robotic instruments to monitor
and investigate important changes in the world’s oceans.
Researchers with the
international Argo program announced they have reached the point
where 1,500 ocean-traveling float instruments—half the
target 3,000-float array— are now operating. This marks
an important milestone in the program’s mission to capture
valuable data around the globe.
The Argo floats, which
are robotically programmed to record and transmit data, are
uniquely positioned to provide important information about climate
and weather phenomena. Other applications of Argo information
include: ocean heat storage and climate change; ocean salinity
changes due to rainfall; ocean-driven events such as El Niño;
impacts of ocean temperature on fisheries and regional ecosystems;
interactions between the ocean and monsoons; and how the oceans
drive hurricanes and typhoons.
“With 1,500 floats
in the water we are now looking at almost the whole planet,”
said Scripps Institution of Oceanography’s John Gould,
Argo international project director. “It’s exciting
to see so many countries involved in Argo and having them cooperate
in monitoring the planet—oceanographers and climate scientists
around the world now regard Argo as the key ocean element of
an underwater global-observing system.”
With the number of
instruments crossing the midpoint, the information being beamed
back from the floats is increasingly being used for science
and weather research. Twelve ocean and climate/weather centers
around the world use Argo data in regional analyses and forecasts.
Scientists such as
Scripps’s Dean Roemmich, chairman of the steering team
for Argo, are using the data for new insights into ocean processes,
information not available only a few years ago.
For example, a recent
joint effort between Scripps Institution and a group from New
Zealand has vastly increased the number of floats deployed in
the south Pacific Ocean. The new data has allowed Roemmich to
make new observations about the area’s ocean circulation
and how currents have become stronger since last measured by
ship-based techniques in the 1990s.
Other scientists are
finding new ways to use the data.
“We will be able
to get information about short-lived events, such as hurricanes,”
said Gould. “When a hurricane is building up and it goes
across an area, if there is a float underneath it you can actually
see how much energy the hurricane has sucked out of the upper
The full Argo array
of 3,000 floats is expected to be deployed by 2007. Argo floats
are autonomous ocean-traveling robots programmed to sink more
than a mile below the ocean surface (see animation)
and drift for as long as four years. Every 10 days the instruments
surface to record temperature, salinity and currents and to
relay the information to satellites. Within hours the information
is transmitted to the Global Telecommunications System and is
freely available on the Internet. The floats then sink again
to begin a new cycle.
The developments leading
to Argo’s ability to operate globally were made in the
early 1990s by Scripps scientist Russ Davis. Twenty-five percent
of the floats in the Argo array are built at Scripps. Each float
is designed for a four-year lifespan, or approximately 150 cycles.
Some have lasted longer.
“If anyone is
concerned about what the climate will be like over a five- or
10-year period, they will have to look to the oceans to find
answers to their questions,” said Gould. “Argo is
becoming one of the key tools for monitoring what is going on
in the oceans. So if there are any surprises, then we will get
prior warning about them from Argo.”
contribute floats to the array and many others provide assistance
with float deployment and access to their nation’s waters.
Woods Hole Oceanographic Institution, the University of Washington
and the National Oceanic and Atmospheric Administration’s
(NOAA) Pacific Marine Environmental Laboratory are United States
float operating partners in Argo. NOAA’s Atlantic Oceanographic
and Meteorological Laboratory (AOML) handles U.S. float data.
The United States also operates one of Argo’s two global
data centers. U.S. Argo is funded by NOAA.
Argo is sponsored by
the World Climate Research Program’s Climate Variability
and Predictability project (CLIVAR) and by the Global Ocean
Data Assimilation Experiment (GODAE). It is a pilot project
of the Global Ocean Observing System (GOOS).
Media Contacts: Mario Aguilera or Cindy Clark
Note: This news
release is issued in conjunction with the Group on Earth Observations
(GEO-5) and the Partnership for Observation of the Global Oceans
(POGO-6) international meetings held the week of Nov. 29, 2004.