HZG researchers target ocean eddies in complex measurement operations
Scientists in the airship’s passenger gondola control the data of the special camera. Photo: HZG/Torsten Fischer
Research has only recently started to focus on small ocean eddies that range in size from a couple of hundred metres to a few kilometres and appear on the world’s oceans just quickly as they disappear again. These vortices could significantly influence ocean currents, nutrient cycles, algae growth and the climate. That is why the specialists at the Institute of Coastal Research are now taking a closer look at them.
Photo: HZG/Burkard Baschek
The large ocean circulation patterns are well known, such as the Gulf Stream, which is several thousand kilometres long. The circulation is unstable in areas where its current is particularly strong – smaller vortices break away, from which even smaller vortices separate. They have a maximum diameter of ten kilometres and are incredibly transient: they have mostly dissipated after half a day.
They appear to have a considerable influence on their environment: these ‘submesoscale’ eddies mix water masses and bring huge amounts of nutrients and microorganisms to the surface. Initial, as yet preliminary studies indicate that the stirring effect of these small yet clearly very frequent eddies may contribute to half of the annual plankton production – and thus around a quarter of the global oxygen production!
The Zeppelin keeps an eye on everything
The research airship travelling towards the Baltic to investigate ocean eddies. Photo: HZG/Torsten Fischer
HZG scientists use numerous measurement and observation devices to investigate the phenomenon more thoroughly. Since the vortices only exist for a few hours, it’s all about speed – and the skilful linking of various measurement vehicles. A plane and a Zeppelin initially patrol a certain maritime region and search for the small ocean eddies in the area under investigation using thermal imaging cameras.
If an ocean vortex is found, a fleet of ships and speedboats make their way to the scene. The boats pull strings with several instruments through the vortex. The attached sensors record water temperatures and salinity, for example. The ships also deploy diving robots to survey what is happening below the surface. A Zeppelin hovers above everything, taking data from the air and coordinating the measurement operation from above.
A microscope for the ocean
Infographic: HZG/Jörg Stiehler
With such concerted action, the researchers are able to examine eddies with a resolution down to one metre – virtually an oceanographic microscope. This makes the Institute of Coastal Research the world’s leading institute when it comes to observing these small ocean eddies.