While the last three decades, the sea ice at the North Pole markedly decreased , on the other side of the world with an area increased . According to Richard Bintan of the Meteorological Institute of the Netherlands and his colleagues intensified melting of the Antarctic ice sheet , which is losing mass at a rate of 250 Gt per year, may be the deciding factor of a small but statistically significant increase of sea ice in the area.
As you know, melt water ice sheets can form a layer of cold fresh water on the surface of the oceans, which protects sea ice from the warmer water. Had to prove that in this case the reason is that.
The authors analyzed the results of satellite and buoy observations of temperature and salinity of the oceans from 1985 to 2010. They then compared the identified changes in global climate models, to assure that the annual loss of 250 Gt of meltwater Antarctic ice sheet may affect the oceans. In this model, the melt water is really fresh-formed barrier that contributed to the expansion of sea ice. Therefore, scientists have concluded that this is the most likely cause of this trend.
Nevertheless, there are other explanations. “This mechanism is indeed there, but the researchers were unable to show that the increased melting has contributed significantly to the increase in sea ice cover,” – says Paul Holland , of the British Antarctic Survey, which last year concluded that the expansion of sea ice caused mostly regional wind rose.
Wind affects the area of ??sea ice in two ways: physically moving it and cooling or heating of the surface of the sea. Using satellite data for 1992-2010 years. Mr. Holland and Ron Kwok of NASA’s Jet Propulsion Laboratory have shown that in certain areas of Antarctica sea ice is changing almost exclusively under the physical action of the wind. In other areas (eg, King Haakon VII Sea ) they are the result of combined effect of wind and temperature.
Mr. Bintan believes that wind plays an important role at the local scale, while the melt-water on the extension of the sea ice in the region. Mr. Holland argues: contrary to the assumption of the authors of the new study does not melt the ice in the same way for the entire coastline of Antarctica, melting concentrated in a few centers.