Antarctica is exhibiting the effects of global warming with the extent of sea ice occurring in winter, according to a study released Sunday. As the ice melts on Antarctica's edges and with minimal snowfall, the sea level is rising and low-lying areas around the world are at risk, the study said.
Scientists who study climate were not clear why the sea ice around Antarctica is growing, as ice on the Arctic Ocean on the opposite end of the planet is reaching record lows.
"Sea ice around Antarctica is increasing despite the warming global climate. This is caused by melting of the ice sheets from below," said the study's lead author Richard Bintanja, from the Royal Netherlands Meteorological Institute (KNMI).
The study explains that as a result of ice shelves on the fringes of Antarctica thawing during the summer, the water that melts floats into the warmer, salty sea water beneath. The summer thaw occurs as a result of an upwelling of warming sea water. Less dense than the saltwater that it flows into, the frigid freshwater stays on the surface and then freezes. After a period of time the formation of more sea ice becomes visible.
According to the study, the cool melt water also affects the amount of water the air holds that then turns into snowfall. Cold air holds less moisture than warm air.
Winds also offer an explanation for the pattern developing in Antarctica. Paul Holland of the British Antarctic Survey and a team of scientists reiterated their findings from last year. They found that wind shifts related to climate change added to the winter ice by blowing a layer of melt water further out to sea.
"The possibility remains that the real increase is the sum of wind-driven and melt water-driven effects, of course. That would be my best guess, with the melt water effect being the smaller of the two," said Holland.
