Will global warming make Antarctica icier?
The South Pole and Ross Sea seen by satellite. "Global warming is not so simple as people like to assume," said Thorsten Markus. "The misconception is that global warming means warmer air temperatures everywhere. This is certainly not the case." (NASA / GSFC)
Climate scientists tell us that we can already observe some effects of global warming in the Arctic’s melting glaciers.
So it might seem counterintuitive that some scientists are predicting that Antarctic sea ice might increase as air surrounding our planet Earth continues to warm.
Thorsten Markus of NASA’s Goddard Space Flight Center has been working with satellite data about snow depth on sea ice in the Southern Ocean surrounding Antarctica. He used that data to calculate a more accurate precipitation rate for the far southern part of the globe than had previously been available. He and his team then made a computer model that generated some surprising results.
Thorsten Markus: With warmer air temperatures the air is able to hold more moisture, which result in increased precipitation. The precipitation is a fresh water source into the ocean as well as adds a layer of snow on top of the sea ice. So and then with this snow layer on top of the sea ice, part of the sea ice is submerged below the sea level, and then we have the snow becomes ice and it makes thicker ice.
Markus said it’s a misconception that global warming means there will be warmer temperatures everywhere on Earth. He reminded us that climate change involves many complex processes.
Thanks today to NASA explore, discover, understand.
With warmer temperatures in the Arctic or Antarctic, precipitation may increase since evaporation increases with temperature. If there is an increase in precipitation, most of it will fall as snow. While this “new” source of freshwater could allow the sea ice layer to expand, its influence on local seawater temperature, regional ocean currents, and surrounding air temperatures is currently not well understood.
Read a complete transcript of Earth & Sky’s interview with Thorsten Markus.
Visit NASA’s Earth Observatory which says it lets you “monitor regional and global changes on our planet almost as they happen.”
Our thanks to:
Thorsten Markus
Microwave Sensors Branch
Laboratory for Hydrospheric Processes
NASA Goddard Space Flight Center
Greenbelt, MD
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