Too late for intervention?: > https://www.sciencealert.com/ticking-time-bomb-hidden-heated-ocean-water-under-arctic-canada-basin-chukchi-sea > > 'Ticking Time Bomb' of Heated Ocean Discovered Hidden Under The Arctic > > The Arctic is not in a good way. Its oldest, thickest sea ice is breaking. > Strange lakes punctuate its landscape. The very chemistry of its water is > changing. > > Things could be about to get worse. New research has uncovered evidence of a > vast reservoir of heated water building up underneath the Arctic Ocean and > penetrating deep into the heart of the polar region, where it threatens to > melt the ice frozen on top. And maybe a lot of it. > > "We document a striking ocean warming in one of the main basins of the > interior Arctic Ocean, the Canadian Basin," explains oceanographer > Mary-Louise Timmermans from Yale University. > > Timmermans and her team analysed temperature data on the Canada Basin taken > over the last 30 years, and found that the amount of heat in the warmest part > of the water had effectively doubled in the period 1987 to 2017. > > (Yale University) > > The basin, which sits to the north of Alaska, is made up of mixed layers of > ocean water, with cold, fresh water flowing at the surface, sitting on top of > a body of warmer, saltier ocean trapped beneath it. > > That dynamic has long been the case, but it's the rapidly heating conditions > of the warmer reservoir below that has scientists concerned. > > "Presently this heat is trapped below the surface layer," Timmermans says. > > "Should it be mixed up to the surface, there is enough heat to entirely melt > the sea-ice pack that covers this region for most of the year." > > According to the researchers, the warmer submerged waters have been > 'archiving' heat due to "anomalous solar heating" of surface waters in the > northern Chukchi Sea, which feeds the Canada Basin. > > Basically, as sea ice seasonally and increasingly melts in the Chukchi Sea, > open water gets exposed to the heat of sunlight, warms up, and is then driven > northwards by Arctic winds – a current phenomenon called the Beaufort Gyre. > > As this heated water travels to the Arctic, the warmer waters then descend > below the colder layer of the Canadian Basin – but the amount they've heated > up in the past three decades could represent "a ticking time bomb", the > researchers warn. > > "That heat isn't going to go away," one of the team, oceanographer John Toole > from the Woods Hole Oceanographic Institution, told CBC. > > "Eventually … it's going have to come up to the surface and it's going to > impact the ice." > > While the researchers don't think there's any immediate threat, strong winds > mixing the colder and warmer water layers – or an increase in salinity, > driving the warmer water upwards – could severely impact Arctic ice. > > And even if those outcomes don't result, the temperature trajectory already > seen could be affecting ice coverage more subtly, although nobody knows the > exact ramifications yet. > > "It remains to be seen how continued sea ice losses will fundamentally change > the water column structure and dynamics," the authors explain in their paper, > although they note in the coming years the excess heat "will give rise to > enhanced upward heat fluxes year-round, creating compound effects on the > system by slowing winter sea ice growth." > > More research is needed to calculate just how serious this situation is, but > there's no denying these mechanisms are all part of a much bigger problem – > and one that isn't going away. > > "We're seeing more and more open water as the sea ice retreats in the > summertime," Timmermans told the Canadian Press. > > "The Sun is warming up the ocean directly, because it's no longer covered by > sea ice." > > The findings are reported in Science Advances. > > > > Sent from my iPhone
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