Russian scientists claim that Arctic Ocean is the main source of carbon dioxide in the northern areas of our planet.
      
      Carbon dioxide is considered to be main greenhouse gas, responsible for global warming. Monitoring shows that seasonal changes of its atmospheric concentrations are located in high latitudes, mostly over the Arctic Ocean.
      
      Russian scientists performed long-term measurements of carbon dioxide concentration in ice-containing air layers and discovered that this greenhouse gas generated in sea ice.
      
      CO₂ usually forms in winter, when new ice appears at under surface of sea ice. Data, collected at 160 drifting stations, show that maximum concentration of CO₂ is observed everywhere in winter, but the highest content of this gas is in the centre of the Arctic Ocean, where about 50-100 cm of new ice grow at under surface of ocean ice.
      
      In summer carbon dioxide is partly absorbed by ice surface. However, since ice grows during 9 months and melts during only 3 months, the ocean emits much more CO₂ than it can absorb.
      
      Researchers performed model experiments, which confirmed their hypothesis. Recent ten years are notable for growing concentration of CO₂ in atmosphere, which is due faster sea ice growth in winter.
      
      Source: Science News