New studies prove once again the enormous impact global warming has on the delicate climate of the polar region. These observations came Thursday from Richard Spinrad, head of research at the National Oceanic and Atmospheric Administration in USA, in releasing the annual update of science’s Arctic report card.
The report states that a particular problem is the disappearance of old, thick sea ice that has been present for thousands of years and is very difficult to get back. Between October and December 2008 temperatures remained an unprecedented +4° C across the central Arctic. This is linked to summer sea ice conditions. The summer of 2008 ended with nearly the same extreme minimum sea ice extent as in 2007, characterized by extensive areas of open water. This condition allows extra heat to be absorbed by the ocean from longwave and solar radiation throughout the summer season, which is then released back to the atmosphere in the following autumn. The report suggests similar warm autumn temperatures over the Arctic in 2009, comparable to those in 2007 and 2008.
The Arctic acts as a natural regulator for the global climate, and that’s mainly dependent on the amount of heat stored in the ocean and ice. There is evidence that, by creating a new major surface heat source, the recent extreme loss of summer sea ice extent is having a direct feedback effect on the general atmospheric circulation into the winter season. Anomalies of greater than +1.0° C were observed well up into the atmosphere. There is evidence that the higher air temperatures in the lower Arctic atmosphere is contributing to changes in the atmospheric circulation in both the Arctic and northern mid-latitudes. Some experts suggest a remote connection even to colder temperatures in Easter Asia.
In fact, the area covered by sea ice is now a quarter below average from 1979 to 2000. The melting also contributes to an unusual high amount of fresh water in the surface layer of the ocean. Ship-based hydrographic surveys showed a continued freshening of the upper 20-m ocean layer in many regions, while in other regions water salinity has decreased.
It appears that some changes may be irreversible. There is no time to loose, because the warming temperatures affecting the Polar North are, in fact, affecting the planet in its natural balance and the whole atmosphere that makes it habitable.