From Green Right Now Reports
In the face of an overall warming trend, how can this be? The group offered an explanation in a paper appearing in the Early Edition of the Proceedings of the National Academy of Science.
“We wanted to understand this apparent paradox so that we can better understand what might happen to the Antarctic sea ice in the coming century with increased greenhouse warming,” said Jiping Liu, a research scientist in Georgia Tech’s School of Earth and Atmospheric Sciences.
Currently, warming conditions accelerate the hydrological cycle, creating more precipitation in the Southern Ocean surrounding Antarctica, mostly in the form of snow. The snow stabilizes the upper ocean and insulates it from the ocean heat below, reducing the amount of melting occurring below the sea ice. (Snow also has a tendency to reflect atmospheric heat away from the sea ice, which reduces melting from above.)
Now, the bad news: Climate models predict that greenhouse gases will continue to increase, resulting in sea ice melting at a faster rate from both above and below. Increased warming will also result in a reduced level of snowfall, but more rain.
“Our finding 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,” said Judith A. Curry, chair of the School of Earth and Atmospheric Sciences at Georgia Tech.