Non-stop SOLO monitoring

Scientists in the US have released into the ocean what are believed to be the World’s first ‘ robotic carbon observers’ to collect information on the role of plankton and other living things in the ocean’s carbon cycle.

The ‘robotic carbon observers’ are a type of float invented by Russ Davis of the Scripps Institution of Oceanography. He dubbed them SOLO (Sounding Oceanographic Lagrangian Observers) and they are said to incorporate new carbon biomass sensors. The SOLO floats can also measure temperature, salinity and mid-depth currents.

From the surface they descend a thousand meters and resurface at dawn and dusk each day.

Each time they surface the floats communicate their collected data, along with their positions, by two-way telemetry link to ORBCOMM satellites. For optimal data collection, the new bidirectional telemetry system allows land-based scientists to control the up and down motion of the floats anywhere in the remote ocean for the first time.

‘This concept experiment will pave the way for a fully instrumented SOLO-carbon observer, able to measure all components of carbon in seawater,’ said Jim Bishop, director of the Ocean Biogeochemical Processes Group in Berkeley Lab’s Earth Sciences Division.

A third of the carbon currently emitted by human activity — roughly two billion metric tons each year — is absorbed in the oceans, but the process is not well understood.

‘The plants that fix carbon in the ocean typically live and die in a single day,’ said Bishop. ‘This makes it really hard and expensive to follow their variability using a ship. When the weather gets bad all work on a ship has to stop, yet biology goes on unobserved.’

The SOLO floats were launched from the US Coast Guard icebreaker Polar Star in the northern Pacific Ocean. Both are now transmitting regularly despite temporary interruption by a storm at sea.