Drones roam oceans for climate data
The Gulf Stream, the warm water current that weaves a serpentine path from the west Atlantic to the United Kingdom, routinely brews some of the most extreme winter storms in the northern hemisphere, disrupting shipping and affecting weather throughout the globe.
The Gulf Stream is also an enormous absorber of carbon dioxide, trapping greenhouse gases and preventing the pace of climate change from accelerating further.
Scientists are now hoping to gain a better understanding of what makes the Gulf Stream tick by launching ‘‘saildrones’’ – or sailboard-like ‘‘uncrewed surface vehicles’’ – that will ride the waters and transmit observations for up to a year.
Developed by the Saildrone company in California, they are used to collect weather and ocean observations and can cover thousands of square kilometres with no carbon footprint.
‘‘We had a competition where we asked what people would do if they had a Saildrone for a month,’’ said Anne Miglarese, Saildrone’s programme executive officer for impact science.
Jaime Palter, a professor of oceanography at the University of Rhode Island, said she would ‘‘stick it in the Gulf Stream’’, Miglarese recalled.
Saildrone was enthusiastic about the proposal. It loaned Palter a unit that was launched in January 2019. Palter’s aim was to better understand how currents like the Gulf Stream fit into the global carbon cycle and how much of a net carbon sink, or absorber, they are.
Humans routinely emit more than 35 billion tons of carbon dioxide annually, about a third of which is believed to immediately end up in the oceans.
Recent Saildrone missions in the Antarctic have shown that the ocean’s role in the carbon cycle may not be as well understood as once believed, which could result in significant changes in how scientists model and research the dynamics of climate change.
‘‘We circumnavigated the Antarctic last year on another philanthropic mission focused on monitoring carbon,’’ Miglarese explained. ‘‘The scientific consensus [at the time] was that the Antarctic [seas were] a sink for carbon. Our science showed it was a source part of the year.’’
According to the paper published with the data, ‘‘observing the Southern Ocean is challenging due to its size, remoteness, and harsh conditions’’, a problem that is also inveterate to the North Atlantic during winter.
‘‘We need a more accurate global carbon budget, and missions like this one will support that and help test our assumptions,’’ Miglarese said.
With the help of a roughly
US$1 million investment from Google, Saildrone will be launching a half-dozen of its drones to roam the North Atlantic. The company has three sizes of drones and is choosing its 7-metre Explorer model for this mission.
The drones resemble enormous surfboards with fins and have a 4.8m sail on top that is used as a mast for weather instruments, solar panels and a camera. It can travel at speeds of three knots on missions lasting up to a year at a time.
The drones are powered by sunlight and wind and wirelessly transmit compressed data back to shore. Some Saildrones are equipped to monitor populations of sharks and other fish and algae.
New ‘‘hurricane wings’’ will be added to Saildrones that the US National Oceanic and Atmospheric Administration will place in the tropics during hurricane season as part of a later project.
Miglarese is looking forward to the rollout of its biggest model yet – the Saildrone Surveyor, a
22m-metre version.