The image above shows our autonomous surface vessel SB Kringla being retrieved after the first of two magnificent field seasons. Now she will be upgraded with both an acoustic sensor for measuring currents and an alternative “high wind” sail.
The new sensor will be a Doppler Current Profiler by Aanderaa AS, measuring from the surface down to 30 -50 meters (depending on conditions). SCOOT is proud to be an early adopter of this sensor on an autonomous platform. Measuring the currents in the ocean surface layer can for example tell interesting things about air-sea interaction and the transfer of wind energy to the ocean, especially together with surface wind data, which SB Kringla is already measuring. The new sail is slightly smaller and more optimised for the high wind conditions in the Southern Ocean. Sails are easily switched between deployments. The upgrade (sensor and sail) will be done by Sailbuoy’s manufacturer, Offshore Sensing AS in Norway.
The Doppler Current Profiler will be used, among other applications, to further enhance our understanding of the role of vertical shear mixing in the S Ocean, which was hypothesised in a recent publication in Geophysical Research Letters, using data from SB Kringla: “Submesoscale Fronts in the Antarctic Marginal Ice Zone and Their Response to Wind Forcing”.
SB Kringla is the first Sailbuoy to be deployed on the Southern hemisphere. SCOOT’s director Sebastiaan Swart often refers to her as “the cute one”, which does not imply that she is spared in any way! Kringla has repeatedly earned battle scars and proven herself as an ultra robust platform in the harshest conditions of the Southern Ocean (see posts from first season and second season). Data from SB Kringla (and the diving Seaglider robots) can be viewed at the website of the project Robotic Observations and Modelling of the Marginal Ice Zone.
The upper video shows a snapshot of SB Kringla during first operator training in Gothenburg. The lower video shows a Sailbuoy battling a storm on the North Sea.