NASA Explains Sea Ice Increase In Antarctica, Melts In Arctic

NASA had released a statement last year revealing that Antarctica's ice was increasing in comparison to the decreasing level of ice in the Arctic. The discovery had left researchers and scientists perplexed about the reason for such a phenomenon. However, now the space agency reportedly has an answer for the sea ice difference at the two poles.

According to a NASA report, it is apparently the geology of Antarctica and the Southern Ocean that is to be blamed. The topography of the white continent and the depth of the ocean that surrounds it influence winds and ocean currents, which subsequently affects the creation, evolution and even sustenance of Antarctica's sea ice cover.

The scientists studied radar data from NASA's QuikScat satellite for a period of 10 years between 1999 and 2009 to observe the path of Antarctic sea ice movement and mark its different kinds. The observations revealed that as sea ice is created and builds up early in its growth season, winds push it offshore and northwards. The process forms a shield of thicker, older ice that circulates around the continent.

The thickness of the sea ice is further enhanced by persistent winds, which are shaped by Antarctica's topography and flow down slope off the continent, leading to a pile up of ice against the massive ice shield. The massive chunk of ice, which measures around 100 to 1,000 kilometers in width, encloses and protects the thinner, younger ice, in the ice pack from the back, from being melted by winds and waves.

A stronger radar signal is returned by thicker, older sea ice as compared to thinner, younger ice. The scientists found that sea ice enclosed within the protective shield was older, rougher owing to longer duration of exposure to waves and wind, and thicker because of more ice growth and snow built up. Furthermore, according to the researchers, areas of open water forms behind the sea ice cover when it expands and ice drifts away from the continent. The areas of open water subsequently create ice factories that are helpful for rapid sea ice growth.