Researchers reveal: Invisible waves are dramatically changing the Arctic!

Researchers reveal: Invisible waves are dramatically changing the Arctic!

A team of researchers from the Alfred Wegener Institute in Bremerhaven has devoted themselves to a fascinating topic: the internal gravity waves in the ocean. These huge waves, which are often the size of high-rise buildings, play an important role in the mixing of the seas and thus also influence global heat exchange and ocean currents. Oceanographer Friederike Pollmann leads the project that studies the effects of climate change on these waves in the Arctic. Surprisingly, it was long thought that there were few internal waves in the Arctic because the ice calmed the surface.

However, the situation has changed: due to climate change, the Arctic sea ice is melting, changing the conditions for the formation of internal waves. Pollmann hypothesized that less sea ice leads to more wind, which stimulates internal waves. This increased mixing could bring warm layers of water up and accelerate ice melting. A vicious circle that would result in faster ice loss and at the same time could further increase global warming.

Recent developments in the Arctic

The current situation regarding sea ice cover in the Arctic is alarming. In February 2023, Arctic sea ice extent averaged 14.31 million km², the seventh lowest since 1979. This data was confirmed by the National Snow and Ice Data Center (NSIDC), which found an even smaller area of ​​approximately 14.18 million km² for the same period, the third lowest February value on record. Such values ​​show a critical negative trend of 2.3% per decade.

What is interesting is that the 2023 melt season began after a winter maximum on March 5, when ice cover increased to 14.79 million km². However, after this period, a continuous decline began, and in various regions such as the Barents Sea and the Sea of ​​Okhotsk, ice extent remained below the long-term average. These changes were due not least to weather phenomena that led to an influx of warm air from the south and further exacerbated conditions in the Arctic.

The role of internal waves

Internal waves, such as those investigated in Bremerhaven research, are crucial for the dynamics of the ocean. They form when tidal currents flow over underwater ridges, influencing the distribution of heat, nutrients and gases. To better understand these complex processes, a laboratory experiment was recently carried out. A model of the ocean was built to observe the transfer of energy through internal waves. Innovative techniques such as Background Oriented Schlieren (BOS) were used to make the waves visible and to track the energy movements within the waves.

The ocean remains a central player in climate change, but the mechanisms behind the mixing are complex. A better understanding of internal waves could not only improve the prediction of future ocean conditions, but also help clarify the role of climate change in marine ecosystems, which is incredibly important for meeting the challenges of our time.

In connection with this, Friederike Pollmann emphasizes the need to test her hypothesis about virtual simulations. The Emmy Noether junior research group “Artemics” will be significantly involved in this. So the coming years could be crucial for how we understand and address sea ice and ocean dynamics under climate change.

For more information on this topic, you can read the following articles: t-online.de, wetterdienst.de and scisimple.com.