Sunday, 15 January 2017

It rains regularly in Antactica where it never used to

Climate Change Shrinking Antarctic Snows

ant_physorg

14 January, 2017

When I used to come to Antarctica in the 1990s, it never used to rain,” said Rodolfo Sanchez, director of the Argentine Antarctic Institute (IAA).

Now it rains regularly—instead of snowing,” he told AFP during an Argentine government visit to King George Island, off the tip of the western Antarctic peninsula.

Scientists monitoring conditions at the base say the average temperature here has increased by 2.5 degrees Celsius (4.5 degrees Fahrenheit) over the past century.

The glacier used to reach all the way to the shore,” Sanchez says. “Now there is a 500-meter (550-yard) wide beach.”

Dark scars of rock are showing through what were once spotless sheets of white snow on the glaciers’ flanks.

Antarctica is a thermometer that shows how the world is changing,” said Adriana Gulisano, a physicist at Argentina’s National Antarctic Directorate.

There is no place where climate change is more in evidence.”


Wildlife signs

Local wildlife also appears to reflect to the change.

Scientists at the Carlini base say a pair of yellow-throated King penguins have swum up to mate nearby for the past three years.

Although the theory is not confirmed, they suspect another sign of climate change. The species had previously been thought to be restricted to warmer spots on the Falkland Islands and the Argentine mainland.

Technician Luis Souza, 56, has divided his time since 1979 between Buenos Aires and the Carlini base, where he has studied migrating birds: cormorants, gulls and penguins.

More crucially, scientists say melting ice is disrupting the breeding of krill, a shrimp-like creature that serves as food for numerous species.


Less ice means fewer krill for the whales, penguins and seals,” said Sanchez. “The whole food chain is affected.”

The conventional wisdom

Since it never rains in Antarctica, does that mean it is technically adesert?

It scientifically is a desert.

Nestled around the South Pole, where the coldest temperature on Earth was recorded and which doesn't receive sunlight for months every year, it's sometimes hard to think of icy Antarctica as a desert. But it is the world's largest one because very little precipitation falls there — on average, it gets less than 2 inches (50 millimeters) a year, mostly as snow.



Despite the low snowfall, vast glaciers cover 99 percent of Antarctica's surface. That's because the average temperature (minus 54 degrees Fahrenheit, or minus 48 degrees Celsius) slows down evaporation to a crawl. Over long periods of time, the snowfall accumulates at a rate faster than Antarctica's ablation, according to "Discovering Antarctica," a project of the U.K.'s Royal Geographical Society.




Parts of Antarctica are showing strong signs of warming up along with global climate change, however. Temperatures in the Antarctic Peninsula have increased by 4.5 degrees Fahrenheit (2.5 degrees Celsius) over the past 50 years — five times the rate of the rest of the planet. And scientists think that warm ocean waters could be melting Antarctica's glaciers as they flow under the floating tongues of ice.

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