Climate change is causing the Arctic sea ice disappear . Source: AP
HEIDELBERG. Last June, the Arctic sea ice melted in record-breaking pace, reported the National Snow and Ice Data Center ( NSIDC ) in the USA in Boulder: Every day , therefore, disappeared 88 000 square kilometers of ice – 80 percent more than the average of the past decades.
Overall, the Arctic may be controlled to a negative record , because in June, the ice extended only on a total of 10.87 million square kilometers. Thus the values lying below the lowest ever measured dimensions from the year 2006, according to the researchers .
Some scientists had predicted that the shrinking of the ice cover of at least several years could increase the biological activity of the Arctic Ocean , which in turn would remove the atmosphere of carbon dioxide : the global warming would thus again somewhat counteracted , the hope of these researchers.
Wei -Jun Cai of the University of Georgia and his colleagues now disagree , however, this thesis : they could prove at least in the Canadian Basin, the western part of the Arctic Ocean occupies no more CO2 uptake .
Although the long-range measurements of Cai’s team have shown that the concentration of CO2 in surface waters of the ocean has increased significantly since 1994, because large quantities of the gas diffused into the sea . Then in the summer – over the winter the sea freezes again – at the same time a stable stratification in the water body stops , there is no exchange with deeper layers, could be shifted to the carbon dioxide.
At the same time was the biological activity in the region fell short of expectations : Fewer plankton withdrew CO2 from the atmosphere and transported over it after his death in the form of carbon to the seafloor .
Here again played a central role in the distinct layers : they prevented vital nutrients could rise from deeper layers. Supply shortage developed , the algae populations worse than expected.
Previous assumptions that increase the carbon dioxide intake could were based primarily on values of coastal marine areas in which stirs offshore winds , the water and thus the rise of nutrient elements , or the depth migration of carbon dioxide allowed – conditions which are not applicable for the central Canada Basin. Overall, this remains the sequestration of newly ice-free regions of the Arctic Ocean is very limited , write the geoscientist .
Compared with June, the Eisschwund in July , according to NSIDC also significantly reduced : The losses amount to only 60 500 square kilometers a day – a quarter less than in long-term average .
The reason: the large-scale weather conditions over the polar region has converted himself. High pressure cells instead pronounced as in June -dominated during the last weeks low pressure areas with low temperatures and thick clouds eisschonenden .