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Big increase in snowfall in the Antarctic



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Media Caption Liz Thomas on the major snowfall in Antarctica: "When things get warmer, they become moister."

Scientists have created a record of snowfall in Antarctica 200 years.

The study shows that rainfall has increased significantly over the period by 1

0%.

In the decade between 2001 and 2010, compared to the years 1801-1810, approximately 272 billion tons more snow was dumped annually on the White Continent.

This annual extra equals twice the volume of water found in the Dead Sea today.

Or in other words, it's the amount of water needed to cover New Zealand to a depth of 1 meter.

Dr. Liz Thomas presented the results of the study at the General Assembly of the European Geosciences Union (EGU) here in Vienna, Austria.

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SPL

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Much of the extra snow has fallen on the Antarctic Peninsula

The British Antarctic Survey (BAS) researcher said that work has been done to put current ice losses into a broader context. "The idea was to get the fullest possible view of the continent," she told BBC News.

"There has been a lot of focus on the recent era of satellites and how much mass we've lost from big glaciers like Pine Island and Thwaites, but actually we do not have a very good understanding of how the snowfall has changed. [19659004] "The general assumption is that it has not changed at all – that it simply remained stable. Well, this study shows that that is not the case. "

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BAS

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Nuclei were collected across the continent – this is the largest study of its kind

Dr. Thomas and his colleagues examined 79 ice cores drilled from the Antarctic. These long cylinders of frozen material are essentially just years of compacted snow.

By analyzing the chemistry of the nuclei, it is not only possible to determine when the snow fell, but also how much precipitation occurred. For example, one key mark used to distinguish one year from the next, even seasons is hydrogen peroxide.

This is a photochemical product that forms in the atmosphere when water vapor strikes sunlight.

"It's perfect for us, Antarctica works like an on-off switch with the long" polar nights "in the winter and long daylight periods in the summer," Dr. Thomas.

The most extensive survey of its kind so far evaluated only 16 cores. The new study is therefore much more representative of the snowfall behavior across the continent.

It turned out that the larger precipitation provided the Antarctic ice sheet with an additional mass of 7 billion tons per decade between 1800 and 2010, and 14 billion tons per decade, if only the 1900 period is considered.

Most of this additional snow fell on the Antarctic Peninsula, which experienced significant increases in temperature in the 20th century.

"The theory predicts that the atmosphere should contain more moisture during Antarctic warming, and that should therefore lead to more snowfall, and what we show in this study is that it has already happened," said Dr , Thomas.

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ESA

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Plant: Satellites routinely subscribe to the Antarctic, but their dataset is only about 25 years old

The BAS researcher wants to emphasize that the increase in snowfall does not contradict the observations of glacier shrinkage and thinning observed by satellites in the last 25 years. Although the additional snow since 1900 has helped lower global sea levels by about 0.04 mm per decade, this will counteract more than the ice lost by the oceans on the edges of the Antarctic, where warm water melts the undersides of the glaciers.

Dr. Anna Hogg from the University of Leeds in the UK uses radar satellites to measure the shape and mass of the ice sheet.

She told BBC News, "Even with these major snowfall events, Antarctica is still losing ice mass faster than it gains mass due to snowfall, mainly due to regions of known ice dynamic instability, such as the Amundsen Sea Embainment, which includes the Pine Glaciers Island and Thwaites include

"The contribution of Antarctic to global sea levels since about 1992 is still our best estimate."

Liz Thomas's research was published in the EGU's journal Climate of the Past.


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