A new study by an international team of scientists explains what’s behind the stagnating trend in sea ice loss in the Arctic Ocean since 2007. The findings suggest that more drastic reductions in sea ice will occur if an atmospheric feature known as the Arctic Dipole reverses itself in its repeated cycle.

Many of the environmental responses to the Arctic Dipole are described in an article published online today in the journal Nature. Science. This analysis helps explain how North Atlantic water affects Arctic Ocean climate. Scientists call this Atlanticization. The research is led by Professor Ihor Polyakov of the University of Alaska Fairbanks College of Science and Mathematics. It is also a branch of the International Arctic Research Center in the Armed Forces of Ukraine.

Co-authors: Andriy V. Pnyushkov, researcher of the International Arctic Research Center; Uma S. Bhatt, Professor of Atmospheric Sciences at the Institute of Geophysics and the College of Natural Sciences and Mathematics of the Ukrainian Academy of Sciences; and researchers from Massachusetts, Washington State, Norway, and Germany.

Polyakov said of the new study: “This is an interdisciplinary look at what’s going on in the Arctic and beyond.” “Our analysis covered the atmosphere, ocean, ice, continental change, and biology changing in response to climate change.”

A large dataset, including direct instrument observations, reanalysis products, and satellite information spanning several decades, indicates that the Arctic Dipole has changed over a cycle of about 15 years, and that the system is likely at the end of its current regime.

In the current “positive” Arctic Dipole mode, which scientists say has been in effect since 2007, high pressure is concentrated over the Canadian section of the Arctic, creating clockwise winds. The low pressure is centered in the Siberian Arctic region and is characterized by counterclockwise winds.

This wind regime drives upper ocean currents, with effects on regional air temperatures throughout the year, atmosphere-ice-ocean heat exchange, sea ice drift and export, and environmental consequences.

The authors write that “water exchange between the Arctic Seas and the Arctic Ocean is critical to the state of the Arctic climate system,” and that the reduction of sea ice is “a true indicator of climate change.”

Analyzing the ocean’s response to wind patterns since 2007, researchers found a decrease in flow from the Atlantic Ocean to the Arctic Ocean via the Fram Strait east of Greenland, as well as an increase in flow from the Atlantic Ocean to the Barents Sea. It is located in the north of Norway and the west of Russia.

The new study calls these alternate changes in the Fram Strait and Barents Sea a “switching mechanism” driven by Arctic dipole modes.

The researchers also found that counterclockwise winds from the low pressure area in the current positive Arctic dipole regime dragged fresh water from Siberian rivers into the Canadian sector of the Arctic Ocean.

The westward movement of fresh water from 2007 to 2021 helped slow the overall loss of Arctic sea ice compared to 1992-2006. The depth of the freshwater layer increased, making it too thick and stable to mix with the heavier saltwater below. A thick layer of freshwater prevents the hot salt water from melting the sea ice at the bottom.

The authors write that the distribution mechanism that regulates the flow of waters beneath the Arctic has “profound” effects on marine life. This could potentially lead to more suitable habitats for arctic subarctic species near the eastern part of the Eurasian Basin compared to the western part.

“We are at the apex of the current positive Arctic dipole regime and it could return at any time,” said Polyakov. “This could have significant climatological implications, including potentially faster rates of sea ice loss throughout the Arctic and sub-Arctic climate systems.” Source