Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Major wind-driven ocean currents are shifting toward the poles


Satellite data gathered over four decades reveals a shift in the positions of the ocean gyres; model-based studies confirm that global warming is largely responsible

In the course of the past 40 years, the major wind-driven current systems in the ocean have steadily shifted toward the poles. Experts at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), came to this conclusion after analysing long-term global satellite data on the ocean surface temperature and sea level height.

Ocean currents.

Photo: Alfred-Wegener-Institut / F. Rödel

Both datasets offer insights into the evolution of large-scale surface currents, and indicate that, in the Northern and Southern Hemisphere alike, the borders of the ocean gyres and their boundary currents are moving closer to the poles, at a rate of over 800 metres per year. This displacement of tremendous water masses is chiefly driven by global warming, as e.g. calculations using a new AWI climate model confirm.

According to the AWI researchers, the consequences of this change can already be felt by human beings and the environment alike: in affected regions, the sea level is rising, indigenous species are migrating, and storms are now following new courses. The study was released today in the journal Geophysical Research Letters.

In our planet’s major wind-driven ocean currents, the water essentially moves around in a circle. There are eight such massive currents, technically referred to as ocean gyres – three in the Atlantic, three in the Pacific, and one each in the Indian and Antarctic Oceans.

These rotating current systems largely determine the weather and marine productivity in our planet’s coastal regions. For example, at their western edge (e.g. the Gulf Stream), the five subtropical ocean gyres transport warmth and moisture from the tropics to the middle and higher latitudes, which in turn influences local air temperatures and precipitation.

In contrast, at their eastern edge (e.g. the Canary Current), a phenomenon known as upwelling pushes nutrient-rich water up to the surface. This water is so teeming with algae, microorganisms and fish that the upwelling areas are also known as the “pantries” of the ocean.

Until recently, monitoring the ocean gyres globally and on an extended basis was infeasible, due to the enormous costs involved in long-term oceanographic observation.

But the AWI experts have now developed a new approach that solves the problem in a relatively simple way: the researchers analysed long-term satellite data on the ocean surface temperature and sea level height, and used the differences in temperature and height to reconstruct the positions and spatial extents of the major current systems.

“When we compared the data, it became clear that, over the past 40 years, all eight wind-driven surface current systems had shifted poleward,” says AWI oceanographer Hu Yang, first author of the study.

The new method also makes it possible to measure the rate at which these currents are shifting: currently 800 metres per year on average. “These changes are particularly apparent in the Southern Hemisphere. In the Northern Hemisphere, factors like the positions of the continents and changes in the Arctic sea ice also affect the courses of the currents; as a result, we also found considerable natural fluctuations, which motivated us to find out which processes are responsible for the shift, and to what extent,” Yang explains.

Simulations with the new AWI climate model reveal the influence of global warming

To do so, the researchers simulated the evolution of the current systems, e.g. with the new AWI climate model. In the first simulations, the starting conditions were equivalent to those for a world with the same level of atmospheric carbon dioxide content as in 1850, the dawn of industrialisation. The experts then gradually raised the amount of CO2 in the Earth’s atmosphere until it was twice the 1850 level, and calculated the potential current development for a range of initial climatic conditions.

Thanks to their advanced modelling efforts, the team succeeded in precisely discriminating between changes caused by global warming, and those produced by natural variations. “Our calculations for a world with high carbon dioxide values produced the same trends that we saw in the satellite data.

And we’re seeing similar changes in the analyses we run with other available model runs from around the globe. In this way, we can show that global warming is a major motor for these shifting currents,” says co-author and AWI climate modeller Prof Gerrit Lohmann.

In addition, the climate simulations offer clues as to which processes in the interaction of the ocean and atmosphere are contributing to the shift. According to Lohmann, “We can see, in various types of observational data, and in our model runs, that the winds powering the currents are now moving poleward. How the individual components of the climate system are interlinked in this regard is an aspect we’re now investigating in follow-up projects.”

The team’s new findings build on those from previous studies, which indicated that especially the gyres’ eastern and western boundary currents were moving toward the poles. “For example, the climate data confirm that during the last ice age, the Agulhas Current was seven degrees of latitude closer to the Equator than it is today,” says Hu Yang. In order to more precisely measure the speed and the drivers of the shift, the long-term satellite data would need to be combined with historical climate data of the water temperature near the gyres’ borders.

The beginnings of a fundamental change in the ocean?

But one thing is already certain: these shifts in the major current systems will have far-reaching consequences for human beings and the environment alike. “For example, as the western boundary currents continue to shift, the courses of winter storms and of the jet stream are following suit. At the edges of the eastern boundary currents, we’re now seeing the rich ecosystems begin to shrink, because the shifting currents are changing the living conditions too quickly for marine organisms to adapt,” Yang explains.

Dramatic temperature changes have been observed e.g. in the Gulf of Maine (due to the shifting Gulf Stream), resulting in a migration of the cod stocks. Researchers have observed similar changes off the Atlantic coasts of Uruguay and Argentina, where the Brazil Current is gradually moving south.

In addition, when boundary currents penetrate higher latitudes, the local sea level rises disproportionately – a problem that especially communities on the northeast coast of North America are now confronted with. And to make matters worse, the displacement of the major subtropical gyres is causing the nutrient-poor regions to expand, reducing the productivity of the ocean as a whole. Accordingly, the shift in the gyres could represent the beginning of a fundamental change in the ocean.

Notes to Editors:

The study was released today in the journal Geophysical Research Letters under the following original title: Yang, Hu et al: Poleward shift of the major ocean gyres detected in a warming climate, GRL, DOI: 10.1029/2019GL085868

The satellite data used in the study covers the timeframe from 1982 to 2018 for the ocean surface temperature, and from 1992 to 2018 for the sea level height.

Your academic contact partners at the Alfred Wegener Institute in Bremerhaven are:

• Prof Gerrit Lohmann, climate modeller (tel.: +49 (0) 471 4831 1758, e-mail: Gerrit.Lohmann(at) He is available for interviews in German and English.

• Dr Hu Yang, oceanographer and modeller (tel.: +49 (0) 471 4831 1897, e-mail: Hu.Yang(at) He is available for interviews in English and Mandarin.

At the AWI’s Communications and Media Relations Department, Ulrike Windhövel (tel.: +49 (0) 471 4831 2008; e-mail: media(at) will be pleased to help you with any questions.

The Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) conducts research in the Arctic, Antarctic and oceans of the high and mid-latitudes. It coordinates polar research in Germany and provides major infrastructure to the international scientific community, such as the research icebreaker Polarstern and stations in the Arctic and Antarctica. The Alfred Wegener Institute is one of the 19 research centres of the Helmholtz Association, the largest scientific organisation in Germany.


Weitere Informationen:

Ralf Röchert | idw - Informationsdienst Wissenschaft

More articles from Earth Sciences:

nachricht New 3D view of methane tracks sources
25.03.2020 | NASA/Goddard Space Flight Center

nachricht East Antarctica's Denman Glacier has retreated almost 3 miles over last 22 years
24.03.2020 | University of California - Irvine

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Junior scientists at the University of Rostock invent a funnel for light

Together with their colleagues from the University of Würzburg, physicists from the group of Professor Alexander Szameit at the University of Rostock have devised a “funnel” for photons. Their discovery was recently published in the renowned journal Science and holds great promise for novel ultra-sensitive detectors as well as innovative applications in telecommunications and information processing.

The quantum-optical properties of light and its interaction with matter has fascinated the Rostock professor Alexander Szameit since College.

Im Focus: Stem Cells and Nerves Interact in Tissue Regeneration and Cancer Progression

Researchers at the University of Zurich show that different stem cell populations are innervated in distinct ways. Innervation may therefore be crucial for proper tissue regeneration. They also demonstrate that cancer stem cells likewise establish contacts with nerves. Targeting tumour innervation could thus lead to new cancer therapies.

Stem cells can generate a variety of specific tissues and are increasingly used for clinical applications such as the replacement of bone or cartilage....

Im Focus: Artificial solid fog material creates pleasant laser light

An international research team led by Kiel University develops an extremely porous material made of "white graphene" for new laser light applications

With a porosity of 99.99 %, it consists practically only of air, making it one of the lightest materials in the world: Aerobornitride is the name of the...

Im Focus: Cross-technology communication in the Internet of Things significantly simplified

Researchers at Graz University of Technology have developed a framework by which wireless devices with different radio technologies will be able to communicate directly with each other.

Whether networked vehicles that warn of traffic jams in real time, household appliances that can be operated remotely, "wearables" that monitor physical...

Im Focus: Peppered with gold

Research team presents novel transmitter for terahertz waves

Terahertz waves are becoming ever more important in science and technology. They enable us to unravel the properties of future materials, test the quality of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

“4th Hybrid Materials and Structures 2020” takes place over the internet

26.03.2020 | Event News

Most significant international Learning Analytics conference will take place – fully online

23.03.2020 | Event News

MOC2020: Fraunhofer IOF organises international micro-optics conference in Jena

03.03.2020 | Event News

Latest News

3D printer sensors could make breath tests for diabetes possible

27.03.2020 | Power and Electrical Engineering

TU Bergakademie Freiberg researches virus inhibitors from the sea

27.03.2020 | Life Sciences

The Venus flytrap effect: new study shows progress in immune proteins research

27.03.2020 | Life Sciences

Science & Research
Overview of more VideoLinks >>>