Antarctic air is warming faster than rest of world.

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Antarctic air is warming faster than rest of world By Mark

Henderson

http://www.timesonline.co.uk/article/0,,3-2111772,00.html

 

New finding could have implications for sea level rises AIR

temperatures above the entire frozen continent of Antarctica have risen three

times faster than the rest of the world during the past 30 years. While it is

well established that temperatures are increasing rapidly in the Antarctic

Peninsula, the land tongue that protrudes towards South America, the trend has

been harder to confirm over the continent as a whole.

NI_MPU('middle'); Now analysis of weather balloon data by scientists at the

British Antarctic Survey (BAS) has shown that not only are the lower reaches of

the Antarctic atmosphere warming, but that they are doing so at the fastest rate

observed anywhere on Earth. Temperatures in the troposphere — the lowest 8km

(5 miles) of the atmosphere — have increased by between 0.5C and 0.7 C (0.9F and

1.3F) per decade over the past 30 years. This signature of climate change is

three times stronger than the average observed

around the world, suggesting that global warming is having an uneven impact and

that it could be greater for Antarctica. It is already known that temperatures

in the Arctic are rising steeply, but with the exception of the Antarctic

peninsula, the data for the southern ice-cap are more mixed. Although the

Antarctic peninsula has warmed by more than 2.5C during the past 50 years, most

surface measurements suggest that there have been no pronounced temperature

changes elsewhere on the continent, while some have indicated a small cooling

effect. The new research, led by John Turner, of the BAS, shows that the air

above the surface of Antarctica is definitely warming, in ways that are not

predicted by climate models and that cannot yet be explained. The results are

published today in the journal Science. “The rapid surface warming of the

Antarctic Peninsula and the enhanced global warming signal over the whole

continent shows the complexity of climate change,” Dr

Turner said. “Greenhouses gases could be having a bigger impact in Antarctica

than across the rest of the world and we don’t understand why. “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.” The

weather balloons from which the data has been collected have been launched daily

from many of Antarctica’s research stations since 1957. These balloons carry

instrument packages known as radiosondes, which measure temperature, humidity

and winds at altitudes of 20km and beyond. The radiosonde data showed a

pronounced warming effect throughout the troposphere during the winter months,

while the stratosphere above cooled appreciably. There is increasing evidence

that greenhouse gases such as carbon dioxide are

creating a blanket about the Earth that traps heat at lower levels, warming the

troposphere and surface, while cooling the stratosphere above. The study is

the third to be published this month to suggest that the effects of global

warming on Antarctica are likely to be more pronounced than has often been

predicted. Research has indicated that the melting of the Greenland ice-cap in

the Arctic could produce sea level rises that destabilise Antarctic ice-shelves,

and Nasa satellite data have shown the internal Antarctic ice-sheets to be

thinning.

 

 

 

 

" Our ideal is not the spirituality that withdraws from life but the conquest

of life by the power of the spirit. " - Aurobindo.

 

 

 

 

 

 

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