100 Days in the Southern Ocean

The 2019 Saildrone Antarctic Circumnavigation marked 100 days in the Southern Ocean on April 29. SD-1020 has sailed more than 7,300 nautical miles since launching from Point Bluff, New Zealand, on January 19.

The challenge of completing the first autonomous circumnavigation of the Southern Ocean is not only the distance—15,000 nautical miles—but the conditions. Storms are fast-moving and frequent, and icebergs and sea ice abound. The Antarctic Circumpolar Current moves up to 150 million cubic meters of water per second (750 times the Amazon River), and whales and marine debris are a constant threat.

Shortly after leaving New Zealand, the fleet was hit by a series of storms with gusts over 60 knots. SD-1022 suffered damage and had to return to port for repairs; the saildrone is expected to relaunch this spring. SD 1020 survived the storm, surfing giant waves and setting speed records. The first major mission milestone occurred five weeks into the mission when SD-1020 crossed 60°S and officially entered the Antarctic Region. In mid-March, SD-1020 completed the first autonomous circumnavigation of Cape Horn.

On April 5, SD-1020 was navigating through “Iceberg Alley” just east of Drake Passage when it made contact with an iceberg. The incident damaged some of the atmospheric sensors and the onboard cameras, but the rest of its science and navigational sensors continue to function normally. As winter approaches, the saildrone will stay slightly further north to take advantage of the available daylight and avoid icebergs.

One of the key aspects of this mission is to perform cross-validation sampling near surfacing SOCCOM floats, to quantify carbon uptake in the Southern Ocean. The Saildrone sensor suite includes an ASVCO2 sensor to measure atmospheric carbon dioxide; SOCCOM floats measure water pH to infer partial pressure of CO2. SD-1020 has completed two successful rendezvouses and is heading toward a third.

Saildrone unmanned surface vehicles (USVs) carry up to 20 science sensors to record meteorological and oceanographic observations above and below the sea surface. SD 1020 is equipped with an Acoustic Doppler Current Profiler (ADCP), which uses sound to measure ocean currents. SD-1022 and SD-1023 are equipped with echo sounders to survey Antarctic krill abundance and study the foraging behavior of chinstrap penguins, both of which are indicators of the changing climate in Antarctica.

“We’re incredibly pleased with how SD-1020 has been faring given the extreme conditions it’s experienced—it’s really above expectations. It hasn’t been easy going, but we’ve learned a lot. Two additional saildrones are scheduled for relaunch in the coming weeks, but this will mean they round Cape Horn in the depths of winter. That’s about as harsh as it gets in the ocean, but we’re looking forward to the challenge!” said Saildrone founder and CEO Richard Jenkins.

SD-1020 is currently southwest of the horn of Africa, at approximately 10°W.  The next significant milestones of the mission will be crossing the prime meridian (0°) and then entering the Indian Ocean (20°E). SD-1022 and SD-1023 are expected to deploy from Point Bluff in late spring (late fall in the southern hemisphere).

A global science collaboration

The Antarctic remains one of the planet’s least explored regions because of its severe conditions and the high cost of exploration. The mission track traverses areas rarely visited by vessels, which means scientists normally don’t have the means to collect essential data related to the marine ecosystem and the global climate.

The 2019 Antarctic Circumnavigation is generously supported by the Li Ka Shing Foundation. Researchers from the National Oceanic and Atmospheric Administration (NOAA), CSIRO Oceans and Atmosphere, and Palmer Long Term Ecological Research are among the mission’s science collaborators. Several additional science collaborators have joined the mission as it continues including the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), the Korea Polar Research Institute (KOPRI), the University of Exeter, and Aker Biomarine/NORCE. In total, science organizations in some eight countries are providing inputs into mission operations and will use the data to further a variety of scientific goals.

Bringing Antarctica to the classroom

Cutting-edge Saildrone technology can be used to expose future generations to the rapid changes taking place in the Antarctic by bringing data-driven lessons to classrooms around the world. Saildrone has partnered with the 1851 Trust, a UK-based education charity that teaches young people about science, technology, and engineering through sailing, to develop a series of STEM-oriented lesson plans, available to teachers free of charge.

Read science-focused blog posts at saildrone.com/missions/antarctica or download the lessons at saildrone.com/missions/antarctica-lesson-plans