Researchers Find Possible Answer to Antarctic Paradox
17.08.2010 - Water & Oceans, Ice & Snow, Antarctic
Although the sea ice extent has been consistently receding in the Arctic, Antarctic sea ice has seen a slight increase in the past few decades. In a paper published in the Early Edition of the Proceedings of the National Academy of Sciences (PNAS), researchers from the Georgia Institute of Technology expose a possible explanation for this paradox.
As the atmosphere warmed over the course of the 20th century, an acceleration of the hydrological cycle resulted in increased precipitation across the Southern Ocean encircling Antarctica. Mostly falling as snow, this added precipitation stabilized the upper ocean, and thus insulated it from the ocean heat below. This, in turn, reduced the amount of melting beneath the sea ice.
Climate models, however, suggest that Antarctic sea ice should eventually experience the same fate as its Arctic counterpart as a consequence of accelerated warming in the 21st century. The sea ice will thus be melting from above and below, while increased warming will further result in an increased level of rain instead of snowfall. Their findings, the researchers say, “raises some interesting possibilities about what we might see in the future. We may see, on a time scale of decades, a switch in the Antarctic, where the sea ice extent begins to decrease”.
