Chasing waves

Ilker Fer heads the first cruise by the Nansen Legacy project equipped with a specially constructed glider and measuring tools.

By Gudrun Sylte, The Bjerknes Centre for Climate Research

– Process studies is the priority of this cruise, says Ilker Fer, Professor of oceanography at The University of Bergen and the The Bjerknes Centre for Climate Research.

A couple of days before departure from Bergen to Longyearbyen, the ice conditions look promising and on board F.F. Kristine Bonnevie all the instruments are in place.

During the next two weeks Fer and his colleagues from The University of Bergen and UNIS at Svalbard will collect data on temperature, salt content, oxygen, current and turbulence from the deep waters.

More research needed

The glider Gnå is especially equipped to measure turbulence and will be in the waters north west of Svalbard for ten days. In September a new cruise will follow and Fer and his colleagues will place additional gliders in the water to follow the northern current of warm Atlantic water.

The Northern Barents sea is an area where climate change is evident, however there is a lack of detailed knowledge. When the sea ice in the Barents sea and Svalbard retreats, it reveals a new sea area. What occurs during this transition?

This is a key question for the national research team of the Nansen Legacy project.

Automation: One robot replaces 15 researchers

When Gnå and other automated gliders follow the northern current, they will be monitoring areas that have previously been unavailable for data collection. One glider alone can collect as much data as 15 researchers.

The Gulf stream brings warm waters to the Norwegian coast and consequently it is  much warmer than other areas at this latitude. The warm Atlantic water branches out near Svalbard and a lot of the water seeps into the Barents sea. It might not be surprising that the sea ice melts when it meets warmer water, but this is not a straightforward process.

When warm meets cold

When the relatively warm Atlantic water meets the cold Arctic water, there is a layering effect. Because the Arctic water is lighter and contains less salt than the warmer Atlantic current it operates as a cover layer between the ice and the Atlantic. However, under certain conditions these layers mix and the resulting warmer temperature causes the sea ice to melt.

– We would like to investigate how these mixing processes occur. In addition we want to measure the heat loss to the sea, the ice and the atmosphere. We know that the mixing processes are influenced by the tide and wind on the surface. That could lead to something we refer to as internal waves between the layers of water, making the water layers mix when the waves brake, explains Ilker Fer.

Translation by Amalie Kvame Holm, The Norwegian Meteorological Institute