2012-09-25 Press release

Research online: new measuring technique enables innovative observations of the North Sea

The Institute of Coastal Research at the Helmholtz-Zentrum Geesthacht and the Alfred Wegener Institute for Polar and Marine Research within the Helmholtz Association are setting up the first underwater data node in the North Sea. This underwater data node functions as a “data plug” at the sea floor that can be connected to ten instrument systems. It is thus possible to carry out real-time year-round measurements of water temperatures, algae concentrations and the sea floor. The data is transmitted directly to the scientists via Internet. The underwater node has been installed today, off Helgoland, at a depth of ten metres.

The tool bag is on the hook and the sensor can be connected. Even for the Helgoland research divers this is no routine operation (yet). Photo: Philipp Fischer, AWI

The underwater data node has been designed by the Institute of Coastal Research at the Helmholtz-Zentrum Geesthacht and was developed in cooperation with the Alfred Wegener Institute for Polar and Marine Research (AWI).

It will allow year-round observations of the condition of the North Sea in areas that are difficult to access. The long-term data series are an important basis to investigate environmental changes in the North Sea. The node has already completed two successful test phases. Now, the measuring system is being permanently installed 700 metres to the north of Helgoland.

A team of the scientific diving centre at the AWI will connect the node at the sea floor where it will remain for several years. The data measured at the underwater node will also flow into the historic long-term data series “Helgoland Reede” of the AWI.

The underwater node itself consists of a 600 kilogramme supporting frame carrying the connectors for the instrument systems. The instruments are provided with electricity via a cable running from Helgoland so that the instruments do not rely on batteries, as is normally the case, but can be operated long-term without further maintenance requirements.

A fibre optic cable transmits the data to the scientists via Internet and enables remote operation of the instruments from the mainland. The coastal researchers have succeeded in developing the first underwater node for use in rough seas at depths of up to 300 metres. Due to its heavy weight the node maintains its position even during storms.

lAll the installations must be checked on land to ensure that the connections fit and everything is completely watertight. Photo: Philipp Fischer, AWI

The underwater node is part of the Coastal Observation System for Northern and Arctic Seas (COSYNA) that was designed by the Helmholtz-Zentrum Geesthacht. Permanently installed sensors regularly measure currents, salinity, oxygen and other parameters.

The data is assimilated into computer models that forecast e.g. ocean currents. Research groups can utilize the node and attach additional instrumental systems. An example is a stereo camera system of the AWI that automatically observes and measures fish and jellyfish.

Two underwater frames (“Lander”) equipped with sensors from the AWI and the Centre of Marine Environmental Sciences in Bremen record physical processes near the sea floor and nutrient exchange between sea floor and water. All data is stored in the COSYNA databank maintained by the Helmholtz-Zentrum Geesthacht.

Alle Installationen müssen "auf dem Trockenen" überprüft werden, damit später die Anschlüsse passen und alles wasserdicht verpackt ist (Foto: Philipp Fischer, AWI).

Background

The underwater node has been developed by the Institute of Coastal Research of the Helmholtz-Zentrum Geesthacht, in cooperation with the Alfred Wegener-Institute of Polar and Marine Research in the Helmholtz Association and the industrial partners 4H Jena and Loth Engineering.

The node is part of the Coastal Observation System for Northern and Arctic Seas (COSYNA), developed by the Helmholtz-Zentrum Geesthacht. The investment costs are 600,000 euro. The Biological Institute Helgoland (Biologische Anstalt Helgoland), that is part of the Alfred Wegener Institute, will operate the node at its location.

The underwater node is part of routine observations of the North Sea carried out with COSYNA and thus helps to observe changes of the ecosystem at Helgoland. The analysis of the data is carried out by the Institute of Coastal Research and the Biological Institute Helgoland (Biologische Anstalt Helgoland). The data is publically available on the COSYNA Internet portal.