Project remOcean: submarine robotics observe the deep ocean

3 September 2010

The Observatoire Océanologique de Villefranche-sur-Mer is launching the remOcean project (“remotely-sensed biogeochemical cycles in the Ocean”) using profiling floats, a new generation of underwater robots that can “yoyo” between the surface and depths of about 2,000 meters. The system will improve understanding of the role of phytoplankton (tiny floating plants that are the basic organisms for transforming CO2 into biological material) in the ocean’s carbon cycle.

The remOcean project will enable researchers to observe oceanic biogeochemical cycles from hard-to-reach regions in real time. The robots will explore five key zones: the North Atlantic, which represents only 1.4% of the world ocean’s total surface but could account for more than 20% of its carbon sequestration, and four large subtropical central zones of the Pacific and Atlantic that are veritable biological deserts about which little is known even though they represent 60% of the ocean’s surface.

A new iridium satellite communication system will allow the researchers to receive data and transmit new instructions each time the robots surface before beginning a new observation cycle. An array of miniaturized sensors will enable the floats to carry out physical as well as chemical (oxygen, nitrates) and biological (chlorophyll and particulate counts) measurements.

The information gathered by remOcean will be cross-referenced with other observation techniques, such as satellites that monitor ocean color. Color can indicate the quantity of phytoplankton in the water: zones rich in phytoplankton are greener while those with lower levels are bluer. Researchers use this information to map the concentrations of phytoplankton for the ocean’s surface, about 1/5 the depth actually occupied by the organisms. The profiling floats will then supplement these maps with information on deeper waters.

The long-term goal of remOcean is to compile the first biological profile of the oceans in three dimensions. The new view could make it possible, for example, to estimate the amount of carbon (CO2) trapped by phytoplankton through the photosynthesis process.

For more information: CNRS website >>