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SOLUTIONS FOR THE OCEAN / INNOVATIONS | 63

THE HISTORIC MISSION The deployment of floaters in coastal currents and
“CORE ARGO” equatorial regions also means that the spatial cove-
rage of the Argo fleet has improved: “It is urgent that
Distributed across all the ocean regions and connec- we begin measuring in highly changeable regions of
ted by satellite to data management centres, Argo’s the ocean” warns Australian oceanographer Susan
network of some 4,000 robotic floats represents the Wijffels, from the Woods Hole Oceanographic Institu-
most abundant and most accurate source of un- tion during the public presentation organised in coo-
derwater temperature, salinity and pressure profiles. peration with the IHO.
Twenty-two years after the programme was first
launched, Argo’s fleet of autonomous instruments
has revolutionised the ways to acquire ocean data, BGC ARGO DEDICATED
previously dependent on campaigns conducted by TO BIOGEOCHEMISTRY
ocean vessels: thanks to Argo floaters, the number
of temperature and salinity profiles currently collected By equipping the floaters with additional sensors to
every year has increased from 5,000 to 130,000. This measure key chemical and biological properties, the
remarkable growth has enabled Argo to improve the new mission BioGeoChemical-Argo (BGC Argo) pro-
accuracy of the models and to document the evolu- vides an opportunity to extend the scope of ocean
tion of the ocean’s physical status over the first two observations to new areas. It now measures 6 key
kilometres of the water column and over close to 70% biogeochemical parameters: light, pH, oxygen concen-
of the planet. Thanks to technological improvements tration, nitrate, phytoplankton and particles. All these
in the floaters, including ice sensing algorithms, the measures will make it possible to document biological
network now includes seasonal sea ice zones as well and ecosystemic resources, and the carbon cycle wit-
as the Polar regions. hin the context of climate change.

2016, A CRITICAL YEAR
Thanks to Argo data, scientists
have noted abnormal temperatures
at depths of up to 2,000 metres
for the past ten or so years. 2016
marked a significant acceleration in
this warming trend, particularly in
the North Atlantic subpolar region.
According to the observations of the
Argo network, this is the result of
a massive absorption of heat and
disruption to ocean circulation which
reinforced penetration towards the
Northeast of warm salty waters
coming from Eastern subtropical
regions.