N. Russian Coast Key Nursery For New Sea Ice, But 80% Of It Now Melts Before Leaving Coastal Waters
The northern coast of Russia is largely considered the most important spot for the formation of new sea ice in the Arctic Ocean, fueled by the area’s shallow waters, frigid winter temperatures, and a strong wind that pushes ice to the open sea. But scientists have discovered that 80 percent of this new sea ice now melts before it can leave coastal waters — up from 50 percent in 2000.
The melting is being driven by the region’s rapid warming, according to the new research published this week in the journal Scientific Reports. Temperatures in the Arctic have risen twice as fast as the rest of the planet.
With just 20 percent of new Russian sea ice making its way to the central Arctic Ocean, the region is losing an important means of transporting nutrients, algae, and sediment, the scientists note. And without new sea ice to replenish the region’s more stable, older ice, “the world is one major step closer to a sea-ice-free summer in the Arctic,” warned Thomas Krumpen, a sea-ice physicist at the Alfred Wegener Institute in Germany and lead author of the new study.
“The ice now leaving the Arctic through the Fram Strait is, on average, 30 percent thinner than it was 15 years ago,” he said. “The reasons: On the one hand, rising winter temperatures in the Arctic and a melting season that now begins much earlier; on the other, this ice is no longer formed in the shelf seas, but much farther north. As a result, it has far less time to drift through the Arctic and grow into thicker pack ice.”
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https://e360.yale.edu/digest/80-percent-of-new-arctic-sea-ice-melts-before-leaving-russian-coast
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New AWI sea-ice study reveals the extreme scale of sea-ice melting in the Arctic
02. April 2019
The dramatic loss of ice in the Arctic is influencing sea-ice transport across the Arctic Ocean. As experts from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research report in a new study, today only 20 percent of the sea ice that forms in the shallow Russian marginal seas of the Arctic Ocean actually reaches the Central Arctic, where it joins the Transpolar Drift; the remaining 80 percent of the young ice melts before it has a chance to leave its ‘nursery’. Before 2000, that number was only 50 percent. According to the researchers, this development not only takes us one step closer to an ice-free summer in the Arctic; as the sea ice dwindles, the Arctic Ocean stands to lose an important means of transporting nutrients, algae and sediments. The new study will be released as a freely accessible Open Access article in the online journal Scientific Reports on 2 April 2019.
The shallow Russian shelf or marginal seas of the Arctic Ocean are broadly considered to be the ‘nursery’ of Arctic sea ice: in winter, the Barents Sea, Kara Sea, Laptev Sea and East Siberian Sea constantly produce new sea ice. This is due to extremely low air temperatures down to minus 40 degrees Celsius, and a strong offshore wind that drives the young ice out to the open sea. In the course of the winter, the sea ice is eventually caught up in the Transpolar Drift, one of the two main currents in the Arctic Ocean. In two to three years’ time, it transports the ice floes from the Siberian part of the Arctic Ocean, across the Central Arctic, and into the Fram Strait, where it finally melts. Two decades ago, roughly half the ice from Russia’s shelf seas made this transarctic journey. Today only 20 percent does; the other 80 percent of the young ice melts before it can become a year old and reach the Central Arctic.
Experts from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) came to this troubling conclusion after monitoring and analysing the sea ice’s movements with the aid of satellite data from 1998 to 2017. “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. 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,” says first author Dr Thomas Krumpen, a sea-ice physicist at the Alfred Wegener Institute.
This trend has been confirmed by the outcomes of sea-ice thickness measurements taken in the Fram Strait, which the AWI sea-ice physicists gather on a regular basis. “The ice now leaving the Arctic through the Fram Strait is, on average, 30 percent thinner than it was 15 years ago. The reasons: on the one hand, rising winter temperatures in the Arctic and a melting season that now begins much earlier; on the other, this ice is no longer formed in the shelf seas, but much farther north. As a result, it has far less time to drift through the Arctic and grow into thicker pack ice,” Thomas Krumpen explains.
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