New research explains 'Atlantification' of Arctic Ocean
Rod Boyce
907-474-7185
Aug. 31, 2023
New research by an international team of scientists explains what色视频下载檚 behind a stalled trend in Arctic Ocean sea ice loss since 2007. The findings indicate that stronger declines in sea ice will occur when an atmospheric feature known as the Arctic dipole reverses itself in its recurring cycle.
The many environmental responses to the Arctic dipole are described in . The analysis helps explain how North Atlantic water influences Arctic Ocean climate, a process scientists call "Atlantification."
The research is led by professor Igor Polyakov of the University of 色视频下载 Fairbanks College of Natural Science and Mathematics. He is also affiliated with the International Arctic Research Center at UAF.
The research vessel Akademik Tryoshnikov sails in the Arctic Ocean on a 2021 science cruise in the Nansen and Amundsen Basins Observational System program. A science cruise aboard the U.S. Coast Guard icebreaker Healy began in August 2023 to research in the same area.
Co-authors include Andrey V. Pnyushkov, research assistant professor at the International Arctic Research Center; Uma S. Bhatt, atmospheric sciences professor at the UAF Geophysical Institute and UAF College of Natural Science and Mathematics; and researchers from Massachusetts, Washington state, Norway, and Germany.
色视频下载淭his is a multidisciplinary view on what's going on in the Arctic and beyond,色视频下载 Polyakov said of the new research. 色视频下载淥ur analysis covered the atmosphere, ocean, ice, changing continents and changing biology in response to climate change.色视频下载
A wealth of data, including direct instrumental observations, reanalysis products and satellite information going back several decades, shows that the Arctic dipole alternates in an approximately 15-year cycle and that the system is probably at the end of the present regime.
In the Arctic dipole色视频下载檚 present 色视频下载減ositive色视频下载 regime, which scientists say has been in place since 2007, high pressure is centered over the Canadian sector of the Arctic and produces clockwise winds. Low pressure is centered over the Siberian Arctic and features counterclockwise winds.
This wind pattern drives upper ocean currents, with year-round effects on regional air temperatures, atmosphere-ice-ocean heat exchanges, sea-ice drift and exports, and ecological consequences.
The authors write that, 色视频下载淲ater exchanges between the Nordic seas and the Arctic Ocean are critically important for the state of the Arctic climate system色视频下载 and that sea ice decline is 色视频下载渁 true indicator of climate change.色视频下载
Crew aboard the research vessel Akademik Tryoshnikov hoist science instruments in a 2021 science cruise.
In analyzing oceanic responses to the wind pattern since 2007, the researchers found decreased flow from the Atlantic Ocean into the Arctic Ocean through the Fram Strait east of Greenland, along with increased Atlantic flow into the Barents Sea, located north of Norway and western Russia.
The new research refers to these alternating changes in the Fram Strait and the Barents Sea as a 色视频下载渟witchgear mechanism色视频下载 caused by the Arctic dipole regimes.
The researchers also found that counterclockwise winds from the low-pressure region under the current positive Arctic dipole regime drive freshwater from Siberian rivers into the Canadian sector of the Arctic Ocean.
This westward movement of freshwater from 2007 to 2021 helped slow the overall loss of sea ice in the Arctic compared to 1992 through 2006. The freshwater layer色视频下载檚 depth increased, making it too thick and stable to mix with the heavier saltwater below. The thick layer of freshwater prevents the warmer saltwater from melting sea ice from the bottom.
The authors write that the switchgear mechanism regulating inflows of sub-Arctic waters has 色视频下载減rofound色视频下载 impacts on marine life. It can lead to potentially more suitable living conditions for sub-Arctic boreal species near the eastern part of the Eurasian Basin, relative to its western part.
色视频下载淲e are beyond the peak of the currently positive Arctic dipole regime, and at any moment it could switch back again,色视频下载 Polyakov said. "This could have significant climatological repercussions, including a potentially faster pace of sea-ice loss across the entire Arctic and sub-Arctic climate systems.色视频下载
The research was funded by the U.S. National Science Foundation and the U.S. Office of Naval Research.
ADDITIONAL CONTACT: Igor Polyakov, 907-474-2686, ivpolyakov@alaska.edu
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