On board the “Polarstern”
to the 6th continent:
Climate Research in the Cold

At the end of last year, we set out with the Polarstern to do even more than before for the explo­ration and protec­tion of the world’s oceans. Now the flag­ship of the Alfred Wegen­er Insti­tute (AWI) is back safe and sound from Antarc­tic waters after sever­al months of research. In this arti­cle in our Valdivia News­room, we take a look at the work of the expe­di­tion — and at an impor­tant deci­sion for the future of German polar research.

On an expe­di­tion in the Weddell Sea

The latest expe­di­tion of the research vessel Polarstern was once again focussed on ocean and climate research. Data was collect­ed in the Weddell Sea to help better under­stand the influ­ence of the polar zone and sea ice on glob­al ocean currents and the climate. Anoth­er task was to supply the German Antarc­tic station Neumay­er III , which is one of almost 30 year-round research facil­i­ties on the 6th continent.

Climate factors take centre stage

The inter­ac­tions between the ocean, sea ice and atmos­phere were a central research topic. Cores were taken from the sea ice and snow samples were analysed. At the same time, a research team equipped Weddell seals with satel­lite trans­mit­ters to gain insights into their diving behav­iour and the hydro­graph­ic condi­tions under the ice

The autonomous Argo rafts, which drift with the current for years and simul­ta­ne­ous­ly create depth profiles, were also used. 41 rafts and 27 perma­nent­ly anchored measur­ing buoys were deployed; 33 decom­mis­sioned buoys were retrieved. The nature of the water itself was also analysed. So-called CTD probes (Conduc­tiv­i­ty, Temper­a­ture, Depth) analysed water columns down to a depth of 5000 metres. In addi­tion to temper­a­ture and conduc­tiv­i­ty, they also measured values such as fluo­res­cence, oxygen and salt content 135 times.

Topog­ra­phy and life in the depths

Anoth­er task of the expe­di­tion was to survey the seabed. To this end, data was contin­u­ous­ly record­ed by sonar during the jour­ney — main­ly in an area of the south­ern Weddell Sea, which covers around one and a half times the area of Bremen. A unique measur­ing device was also used: the OFOBS (Ocean Floor Obser­va­tion and Bathym­e­try System ). It hovers just above the seabed and takes photos and video record­ings. This allows scien­tists to gain insights into the exot­ic world of life in the lowest metres of the water column and can also measure the topog­ra­phy in high reso­lu­tion. Almost like “our” Valdivia 125 years ago, the OFOBS was also equipped with a fish­ing net and thus helped to further inves­ti­gate the isolat­ed ice fish and their breed­ing nests.

An impor­tant step towards the future 

Since the begin­ning of the year, Thyssenk­rupp Marine Systems in Wismar has been work­ing on design­ing the succes­sor to the current Polarstern. The Alfred Wegen­er Insti­tute can now look forward with confi­dence to contin­u­ing its valu­able work and inter­na­tion­al research into polar icing in partic­u­lar. The Feder­al Ministry of Educa­tion and Research and the Budget Commit­tee of the German Bundestag had already  the award of the contract in Decem­ber 2024. In Febru­ary, the then Feder­al Research Minis­ter Cem Özdemir person­al­ly visit­ed the new build­ing, which sets stan­dards for Germany as a research loca­tion and for climate protec­tion — for exam­ple with green methanol as a possi­ble fuel.

A new “guid­ing star” for polar and  research 

“We are delight­ed that construc­tion (…) can now begin,” said AWI Direc­tor Prof Dr Antje Boetius. “What happens in the ocean and the polar regions affects all of human­i­ty. The ocean is vital for survival due to its func­tion as a heat and carbon reser­voir. It is full of fasci­nat­ing life that needs to be protect­ed. Oceans and coasts feed us, are recre­ation­al areas, provide renew­able ener­gy and mate­ri­als and open up glob­al trans­port routes

The new Polarstern is designed as a float­ing research plat­form that is equipped for a wide range of marine science disci­plines — from geol­o­gy and geophysics, marine biol­o­gy and oceanog­ra­phy to sea ice and atmos­pher­ic research. The new build­ing, which is almost 160 metres long and 27 metres wide, will have space for around 60 scien­tif­ic expe­di­tion partic­i­pants and 50 crew members. In addi­tion to vari­ous labo­ra­to­ries and perma­nent­ly installed research equip­ment, the Polarstern II will also carry mobile systems such as under­wa­ter and flying drones.

Valdivia and the sea — a profound connection

Depth in perfor­mance, passion for the sea — that’s how we found our name Valdivia. This is because “Valdivia” was the name of the first German research vessel to set out on a system­at­ic explo­ration of the deep sea in 1898. This connec­tion moti­vates us to support the explo­ration and protec­tion of the oceans in a prac­ti­cal way: as a spon­sor of the Alfred Wegen­er Insti­tute and the “One Earth One Ocean” project for maritime waste disposal.

(Image source: AWI)