Antarctic Sea Ice Hits Record … High?

A map of Antarctic sea ice.

Despite frequent headlines about a warming planet, melting sea ice, and rising oceans, climate analysts pointed to a seeming bright spot this week: During Southern Hemisphere winters, sea ice in the Antarctic, the floating chunks of frozen ocean water, is actually increasing.

In fact, in late September, satellite data indicated that Antarctica was surrounded by the greatest area of sea ice ever recorded in the region: 7.51 million square miles (19.44 million square kilometers), the U.S. National Snow and Ice Data Center announced Thursday. Even so, it’s a slow rate of growth—about one percent over last year—not nearly enough to offset melting in the Arctic, which broke records just weeks ago.

National Geographic asked Eric Rignot, a NASA researcher and earth systems professor at UC Irvine, whether the data is good news, and what it means for the rise of global sea levels, which are fueled by melting ice.

This Antarctic record seems counter to what we often hear about sea ice shrinking. How can we explain growing sea ice?

If the world was warming up uniformly, you would expect the sea ice cover to decrease in the Antarctic, but it’s not. The reason for that is because the Antarctic is cooler than the rest of the world. It’s warming up as well but not as fast as other places.

So you have the warming world and a cold Antarctica, and the difference between the two is increasing. That makes the winds around Antarctica move a little bit faster. There’s also a difference that comes from the depletion of ozonein the stratosphere in the Antarctic, which makes the stratosphere colder.

That’s the leading explanation for what we’re seeing in the Antarctic, but you have to acknowledge that the effect is very small.

 

The National Geographic has the full article

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