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Antarktis Eis- und Klimaforschung
Rapid temperature increases above the Antarctic 2006
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Unexpected warming in Antarctica
Arktis - Antarktis
Naturwissenschaften Klimawandel Geografie-Erdkunde Klima
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Antarktis - Antarctica
«Rapid temperature increases above the Antarctic»
Significant warming of the Antarctic winter troposphere
A new analysis of weather balloon observations from the last 30 years reveals that the Antarctic has the same 'global warming' signature as that seen across the whole Earth, but is three times larger than that observed globally.

The results by scientists from British Antarctic Survey are reported in Science magazine.

Although the rapid surface warming in the Antarctic Peninsula region has been known for some time, this study has produced the first indications of broad-scale climate change across the whole Antarctic continent.

Lead author Dr John Turner of the British Antarctic Survey says,

"The warming above the Antarctic could have implications for snowfall across the Antarctic and sea level rise. Current climate model simulations don't reproduce the observed warming, pointing to weaknesses in their ability to represent the Antarctic climate system. Our next step is to try to improve the models."

Daily launches of weather balloons
Daily launches of weather balloons have been carried out at many of the Antarctic research stations since the International Geophysical Year of 1957-8. The balloons carry instrument packages called radiosondes that measure temperature, humidity and winds up to heights of 20 km or more. Recently many of the old radiosonde records have been digitised and brought together in a project funded by the Scientific Committee on Antarctic Research.

Analysis of the radiosonde data showed a winter season warming throughout the troposphere, which extends up to about 8 km, and cooling in the stratosphere above.

The largest warming of almost three quarters of a degree Centigrade per decade was found close to 5 km above the surface.

This is over three times the rate of warming observed for the world as a whole. The warming has occurred across the whole of the Antarctic and is apparent in the balloon data from Amundsen-Scott Station at the South Pole to the many stations along the coast of East Antarctica.

Although climate change at the surface of the Earth receives wide attention, the atmosphere in recent decades has in fact warmed most some 4-5 km above the surface, with the stratosphere cooling above.

There is increasing evidence that levels of greenhouse gases have provided a blanket above the Earth trapping heat at lower levels and giving cooling in the layers above.

Air temperatures in the Antarctic Peninsula region have risen by over 2.5°C in the last 50 years, about 5 times faster than the global mean rate.

In recent decades both Polar Regions have shown very contrasting patterns of change at the surface, with the Arctic warming markedly, while there has been little change in the Antarctic outside of the Antarctic Peninsula region.

Changes above the surface have not been investigated previously.

British Antarctic Survey is a world leader in research into global issues in an Antarctic context. It is the 's national operator and is a component of the Natural Environment Research Council. It has an annual budget of around £ 40 million, runs nine research programmes and operates five research stations, two Royal Research Ships and five aircraft in and around Antarctica.

The paper 'Significant warming of the Antarctic winter troposphere' is published in Science on 30 March 2006.

Source: Text British Antarctic Survey, 30. March 2006


Unexpected warming in Antarctica

Data from nine research stations were used in the study

Winter air temperatures over Antarctica have risen by more than 2C in the last 30 years, a new study shows.

Research published in the US journal Science says the warming is seen across the whole of the continent and much of the Southern Ocean.

The study questions the reliability of current climate models that fail to simulate the temperature rise.

In addition, the scientists from the British Antarctic Survey (BAS) say the cause of the warming is not clear.

It could be linked to increases in greenhouse gases in the atmosphere or natural variations in Antarctica's climate system.

Source: BBC Science, 1 April 2006


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