April 3 (UPI) -- Just 20 percent of the ice formed in the sea ice nurseries in the shallow, marginal seas along Russia's northern coast are reaching the Central Arctic. Most of the ice melts before it ever leaves its birthplace.
According to a new study by scientists at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, the loss of ice in the Arctic has disrupted the sea-ice transport across the Arctic Ocean.
The extent of Arctic sea ice expands and contracts with the seasons. The growth of the Arctic's sea ice extent relies upon new ice, much of which forms in coastal seas, including the Barents Sea, Kara Sea, Laptev Sea and East Siberian Sea. Low temperatures create ideal ice-forming conditions among these marginal seas, and strong offshore winds help drive newly formed ice into the open ocean where it gets caught up in the transpolar drift and makes it way toward the Central Arctic.
Prior to 2000, half the ice formed among Russia's shelf seas completed the journey across the Central Arctic, from the Siberian coast to the Fram Strait. Today, 80 percent melts before it ever leaves the nursery.
Researchers used satellite data collected between 1998 and 2017 to document the movement of ice across the Arctic.
"Our study shows extreme changes in the Arctic: the melting of sea ice in the Kara Sea, Laptev Sea and East Siberian Sea is now so rapid and widespread that we're seeing a lasting reduction in the amount of new ice for the transpolar drift," Thomas Krumpen, a sea-ice physicist at the Alfred Wegener Institute , said in a news release. "Now, most of the ice that still reaches the Fram Strait isn't formed in the marginal seas, but comes from the Central Arctic. What we're witnessing is a major transport current faltering, which is bringing the world one major step closer to a sea-ice-free summer in the Arctic."
Because their is less new ice arriving in the Fram Strait, there is less ice leaving the Fram Strait. Measurements proved the ice leaving the strait is 30 percent thinner than it was 15 years ago.
Today, most of the ice moving in and out of the Fram Strait is formed in open ocean. The ice boasts less algae, sediments and nutrients than ice formed in the marginal seas. River-deposited minerals and sediments also get frozen in the ice forming along the Siberian coast.
"Instead of Siberian minerals, we're now finding more remains of dead algae and microorganisms in our sediment traps," said AWI researcher Eva-Maria Nöthig.
The shift in particle transport cycles could eventually trigger biochemical changes in the Arctic, changes that could alter Arctic ecosystems.
Researchers published their analysis of the fracturing sea-ice transport this week in the journal Scientific Reports.
