The eastern Arctic Ocean is becoming more like the Atlantic Ocean, a new study combining remote sensing and local data finds. Whereas the Arctic Ocean typically undergoes very little vertical overturn, the eastern Eurasian Basin of the Arctic is now becoming more active, exhibiting vertical mixing more commonly seen in iceless parts of the Atlantic, the study finds. Over the last decade, the Arctic Ocean has experienced record-breaking losses of sea ice in the summers. Indeed, the eastern Eurasian Basin has been nearly ice-free at the end of summer since 2011. Here, Igor V. Polyakov analyzed satellite estimates of ice thickness in this region collected between 2013 and 2015, as well as data on ocean conditions from this period collected from buoy monitoring systems spread across the Arctic. By comparing this data to previously published work, they found that the eastern part of the Eurasian Basin is evolving a state of weakened stratification (meaning less layer formation, and thus fewer barriers to nutrient mixing), increased vertical mixing and less sea ice. These changes will have substantial impacts on other geophysical and biogeochemical components of the Arctic Ocean system, the authors say, citing enhanced atmosphere-ocean interactions, altered freshwater storage and export patterns, changes to ecosystems, and possibly changes to the ocean's response to acidification.
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Journal
Science