AUV tests in the Koster fjord
For five days a research team has visited the Lovén Centre Tjärnö to test an Autonomous Underwater Vehicle (AUV) in the Koster fjord prior to an Arctic expedition this coming summer.
The group who conducted the tests consists of Thorben Wulff, Sandra Tippenhauer and Sascha Lehmenhecker from AWI – Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research – in Bremerhaven.
Robotic exploration scientist Thorben Wulff and physical oceanographer Sandra Tippenhauer make sure the instruments in the AUV are functioning properly. Photo: Siri Björnsdotter.
Thorben Wulff makes the last preparations prior to dive. Photo: Siri Björnsdotter.
The 4.5 metre long, 500 kg heavy, torpedo shaped underwater vehicle ”PAUL” is equipped with a water sample collector as well as various instruments: microstructure probe measuring turbulence, water current meter (ADCP, Acoustic Doppler Current Profiler), fluorometers to measure chlorophyll and CDOM (Colored dissolved organic matter). In addition, there are instruments for measuring nitrate, oxygen, light, (PAR), salinity, temperature and depth. The AUV was deployed from the research vessel Nereus into the deep Koster fjord and travelled according to preprogrammed dives before it was retrieved on board, and measurements was downloaded.
The AUV ”PAUL” is deployed from research vessel Nereus. Photo: Siri Björnsdotter.
Sandra Tippenhauer, Thorben Wulff and engineer Sascha Lehmenhecker are retrieving the AUV on board, and measurement data will be unloaded. Photo: Siri Björnsdotter.
The tests were conducted prior to a larger expedition in August, to the Fram Strait west of Svalbard and to a site outside the 79 °N glacier east of Greenland.
– Our three-day tests worked out very well, after some minor problems but that’s normal. The infrastructure here at the Lovén Centre Tjärnö is very nice, with friendly and helpful staff on Nereus and on land, says Thorben Wulff.
A closer test site for the Bremerhaven scientists is Helgoland, but with maximum 55 metres depth and also often facing troubling high waves in the North Sea. Thus, the deep sea site in the Koster fjord under the lee of the Koster Islands is convenient. The research group has previously tested the AUV outside the Lovén Centre Kristineberg, in the Gullmar fjord.
– The Gullmar fjord and the Koster fjord are perfect deep sea test sites, says Thorben Wulff.
The Lovén Centre will buy an AUV of similar size. It will be used from new R/V Skagerak.