The Transpolar Drift is faltering 


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.

Source: The Transpolar Drift is faltering — sea ice is now melting before it can leave the nursery