Deep sea gliders on patrol

LARGE fleets of robotic gliders could soon be deployed on six-month missions to gather information on how the Southern Ocean is affected by climate change.

That’s the vision of Sebastiaan Swart, from South Africa’s Council for Scientific and Industrial Research and a vicechairman of the Southern Ocean Observing System that is holding international workshops in Hobart this week.

The new organisation aims to co-ordinate an international effort to ramp up scientific observations in a region that is described by participants as one of the world’s hottest climate-change hot spots.

Since 2011 Prof Swart’s South African team has pioneered the deployment of two types of craft in the Southern Ocean — wave gliders and diving gliders.

The wave gliders, like slightly oversized surfboards, can be propelled by waves across the ocean’s surface.

They could travel autonomously all the way from a port such as Cape Town or Hobart to the remotest regions of the Southern Ocean at speeds of up to 5km/h.

Prof Swart said the wave gliders had proved excellent at monitoring the exchange of carbon dioxide between the ocean and the atmosphere.

The diving gliders can adjust their buoyancy so that they rise and sink and, like a gliding aircraft, can move forward as they do so.

They can patrol water columns as deep as 1000m, while new designs under development could dive as deep as 6000m.

Prof Swart said the diving gliders could also be trained to work under ice and the two types of gliders could also be effective when tied together as pairs.

“Compared to a ship they are a fraction of the cost,’’ he said.

“We could see large fleets of gliders, in the tens to hundreds, collecting data.’’

A United States program involving Rutgers University also deploys gliders around the Antarctic Peninsula.