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What are the different uses of Argo data?
Profiling float data from Argo and from
earlier deployments have an enormous range of applications. As
the float array grows
and Argo data become more and more abundant there is an increasing body of scientific
literature
based wholly or partly on Argo. The project maintains a
bibliography of
peer- reviewed papers
that refer to profiling floats and another
that covers
all
aspects of the use of neutrally-buoyant
floats back as far as their origins in
1955. Additionally, many new research
papers
are in preparation or about to be published. Early applications of Argo data were highlighted in Argo's
First Science
Workshop held in Tokyo in November 2003. More recent applictions of Argo data were
presented at the
Second Argo Science Workshop in Venice in March 2006.
Argo data use falls into three main categories: educational uses, operational uses and research
uses. Read the synopsis of each data type and follow the links to more detailed pages.
- Educational Uses
Argo data are easy to access and are truly global. Their relevance to climate issues
such
as global warming that have great socio-economic relevance makes Argo an ideal vehicle
through which to highlight the importance of the oceans to the general public and
particularly
to schools. As a first step towards this goal, Argo is the focus of the
SEREAD
project directed to schools throughout the South Pacific region.
- Operational Uses
Centers in Australia, France, Japan, the UK and the USA routinely produce global and regional
analyses of subsurface properties using the Argo data stream. These are available on the world
wide web (see the
Use by Operational Centers page) and will give early warning of significant temperature and salinity anomalies and changes
in ocean circulation.
In the Gulf of Alaska and around Japan, Argo data are being used to aid the monitoring of
environmental conditions that affect fish stocks and biological productivity.
Each summer the UK Met Office issues a forecast of conditions for the following winter based
on the subsurface temperatures in the Atlantic Ocean. Argo data now allow these forecasts to
be made with greater confidence.
At short time scales, Argo data have been used to
study the evolution of near-surface temperature
and salinity beneath
tropical cyclones. The data show clear temperature differences left
and right
of the cyclone track, but produce conflicting patterns of
salinity change. Monsoons and ENSO
events dominate the low-latitude
seasonal/inter-annual ocean-atmosphere variability. Argo data,
when
combined with TAO/Triton tropical buoy array data, extend the mapping
of tropical Pacific
Ocean structures, and are also used in ENSO
forecast systems. Argo profiles have also revealed the
Arabian Sea
space-time response during the summer monsoons of 2002 and 2003.
Many results focused on exploration of the
circulation and the definition of the properties and
abundance of
winter-formed mode waters in mid-latitude ocean basins. This could
even be done in
areas such as the Okhotsk Sea, where there is
extensive ice cover in some years. Twelve operational
analysis/forecast centers routinely use Argo data, and through GODAE,
are routinely producing ocean
state products. Improvements in ocean
predictions from assimilating Argo data were demonstrated at
the
workshop. These give an exciting foretaste of the likely impact of
the full Argo array when
combined with remote sensing data.
- Research Uses
Although the Argo array is not yet complete,
its impact on global-scale problems can already be
seen from studies
such as Willis et al. [2003], where Argo allows heat and fresh water
storage in
the ocean to be estimated. Its advantage over ship-based
observations is the uniform geographical
and seasonal distribution,
depth penetration (deeper than the typical 750 m of XBTs), and data
volume.
Argo data have been shown to be of high
enough quality to document changes over almost 20 years in
subsurface
salinity across the south Indian Ocean, an area where climate change
models predict
that anthropogenic change will be most easily detected
[Banks and Wood, 2002]. However, applications
of this type highlight
the need for caution in adjusting float data to climatological
values.
In the western Atlantic, year-to-year changes in the properties and circulation of water masses formed
each winter have been analyzed for the first time. These changes are a senstivite indicator of the
interaction between the atmosphere and ocean.
For the first time we have been able to monitor the impact of the Asian Monsoon on the temperature
and salinity of the Arabian Sea.
While much emphasis is placed on Argo profile
data, velocity estimates both at depth and from the
floats' time at
the surface have been used for the global estimation of inertial
oscillation statistics
to reveal hitherto unsuspected subsurface
circulation patterns. When combined with surface drifter
data and T/S
profiles, they can be used to derive velocity field estimates on
basin (and ultimately
global) scales throughout much of the water
column.
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