Hamburg-based geophysicist awarded with Helmholtz Doctoral Prize

30 April 2024, by Miriam Frieß

Photo: David Marschalsky

Offshore wind turbines affect local ocean and wind currents in the North Sea – as, drawing on simulations, Dr. Nils Christiansen from the Helmholtz Centre Hereon was able to show in his dissertation: the turbines slow air currents and ocean currents alike. For his work, the CLICCS researcher has now been awarded the Helmholtz Doctoral Prize.

Wind power is broadly considered to be an essential component of the energy transition, which is why more and more turbines are being installed along Europe’s coastlines in what are called offshore wind parks. In this regard, to date the North Sea has been the most important region: it is currently home to more than 5,000 turbines spread across over 100 offshore wind parks. Dr. Nils Christiansen investigated how the turbines are affecting ocean physics. “In the upper water layers of the North Sea, the wind is one of the main drivers for currents,” says Christiansen. “When the wind is slowed down by turbines, it also affects ocean currents.” This aspect in turn affects the mixing and temperature in the topmost water layers.

Offshore Windparks change Ocean Physics

And something similar takes place in the water near the turbines’ bases: the natural ocean currents are slowed and turbulence is created. These effects can change the nutrient distribution in the water, influencing wind parks’ surrounding ecosystems. For example, if more nutrients find their way to the upper water layers, it can intensify plankton growth; if the changed physical conditions mean fewer nutrients in the upper layers, plankton growth declines.

“The effects are highly complex and depend on a range of factors,” Christiansen stresses. “What we know at this point is that the system is changed by the offshore wind parks. But we can’t yet make any general statements on the direction it is changing in.” Though these changes tend to be on a comparatively small scale, they nevertheless concern an area measuring several hundred square kilometers.

Every year, the Helmholtz Doctoral Prize is awarded in recognition of exceptionally good, original, and creative dissertations addressing the Helmholtz research areas. This year’s awards ceremony was held on April 29 in Berlin. “When your work is application-based and socially relevant, it’s very rewarding for it to be acknowledged,” says Christiansen.