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Friday, November 2, 2012

The Antarctic Grow While Arctic Shrink?

Antarctic Peninsula that is characteristic of the continent at the south end of the earth that seemed to vanish. Dark blue sea surrounding sea ice is now closed. The formation of sea ice is not just going around the peninsula, but also across the edge of the continent that now appears larger.
Photo of the Ross Ice Shelf in Antarctica. (Picture from: http://www.extremescience.com/)
Satellite images in September showed that the area of ​​sea ice surrounding Antarctica reached 19.44 million square kilometers. Ice extent was the highest point ever recorded in Antarctica. Growth rates on the continent of origin penguin ice broke records created six years ago, when sea ice coverage in the Antarctic reached 19.39 million square kilometers.
September 2012 witnessed two opposite records concerning sea ice. Two weeks after the Arctic Ocean's ice cap experienced an all-time summertime low for the satellite era (left), Antarctic sea ice reached a record winter maximum extent (right). But sea ice in the Arctic has melted at a much faster rate than it has expanded in the Southern Ocean, as can be seen in this image by comparing the 2012 sea ice levels with the yellow outline, which in the Arctic image represents average sea ice minimum extent from 1979 through 2010 and in the Antarctic image shows the median sea ice extent in September from 1979 to 2000. (Picture from: http://www.sciencedaily.com/)
Sea ice around Antarctica grew to the
greatest size ever before observed
 on September 26, 2012. (Picture from:
 http://www.earthweek.com/)
Growth in Antarctic sea ice is making the researchers confusion. Therefore, the growth of ice in the Antarctic occurred in the midst of global warming melting the Arctic largely ice in the Arctic.

"While the whole world is getting hotter over the last half century, most of Antarctica was even more cool," said Ted Scambos, a scientist from the U.S. National Snow and Ice Data Centre (NSIDC) in Colorado, last week.

Scambos observe growth of the Antarctic ice coverage over the past few decades. His research shows that over the last 30 years extensive sea ice (frozen ice layer over the ocean) in the Antarctic reached 12.08 million square kilometers. This figure is greater than that recorded in 1979. "The growth of 1 percent per decade," he said.

This contrasts with the ice conditions in the Arctic, which is running low. Satellite image of the United States Space Agency (NASA) showed that the Arctic ice loss of 4 percent per decade. Over the last 30 years, the Arctic has lost an average of 14.76 square kilometers of ice per 1 square mile of ice that grow in Antarctica. In the last month, recorded a record low Arctic ice shrank to 3.41 million square kilometers numbers.
New images Nasa show reveal the full extent of Arctic ice shrinkage, showing a new record low compared to the average minimum extent over the past 30 years (in yellow). (Picture from: http://www.dailymail.co.uk/)
Island of Greenland, which is located near the Arctic ice shrinkage worst. In July, an iceberg twice the area of ​​Manhattan (87.5 square miles) has broken away from the Petermann Glacier on the island area of ​​2.16 million square kilometers. This is the second large iceberg separated from the main glacier in less than 2 years.
Scattered ice floes are seen from the bridge of the RV Healy on August 20, 2012 northwest of Barrow, Alaska. (Picture from: http://www.dailymail.co.uk/)
This giant chunk of ice not only affects rising sea levels, but also threatened the ship traffic in the North Atlantic and offshore oil rigs on the east coast of Canada.

Greenland is one of the land surrounding the Arctic, in addition to Canada, Russia, Iceland, Norway, Sweden, Finland, and the United States. The largest island in the world that are part of the Kingdom of Denmark is located in the northern part of the Atlantic Ocean in the northeast of Canada.

Massive ice melt in Greenland bodes anomalies in the Arctic. Therefore, the land and sea around Greenland ice sheet should be covered throughout the winter in September. The number of new ice decreased to the minimum point in February, towards the end of summer in the southern hemisphere.

"The increase in ice area in Antarctica get less attention than the loss of Arctic ice," said NASA Chief Scientist, Waleed Abdalati. "Whereas the addition of ice in Antarctica as important as the loss of ice in the Arctic."

Antarctic ice growth is quite significant. Claire Parkinson and Donald Cavalieri, two sea ice scientists involved in the NASA Aqua satellite mission, said that the sea ice in Antarctica increased by approximately 17.1 thousand square kilometers per year in 1979-2010. Most of the increase occurred in the Ross Sea. Landscapes of sea ice in the Weddell Sea and the Indian Ocean is also increasing, although on a small scale. At the same time, and Amundsen Sea Bellinghausen Sea lost most of its ice.

"Strong pattern of decline in ice coverage in the Bellingshausen and Amundsen Sea region as well as increased coverage of ice in the Ross Sea region is the impact of changes in atmospheric circulation," said Claire and Donald.

NASA launched a satellite map of the recordings that describe the scope of the entire Antarctic ice cover on 26 September 2012. This map is based on analysis of data collected from sensors NSIDC microwave specially flown through the defense meteorological satellite program.

In this map, the continent looks dark gray colored partly covered glaciers (light gray). Around the continent, there is a layer of ice that floats on the ocean (white) limited the extent of the yellow line. Ice growth was recorded at 0.9 percent per decade.

"In 2012 reinforces the contradiction between the two hemispheres, the decline in Arctic sea ice coverage and increased coverage of sea ice in the Antarctic," said Parkinson.

Scambos said that this contradiction is due to anomalous conditions of climate change impacts for the unexpected. Therefore, Antarctica, Äîseperti other parts of the earth, Äîseharusnya not be separated from the effects of global warming.

The scientists also mapped the surface of the sea ice of Antarctica. The first three-dimensional map allows them to measure the thickness of Antarctic sea ice at the same time accurately determine the impact of climate change there. Using robot submarines, a team of scientists from eight countries to map Antarctic iceberg of reverse perspective.

Three-dimensional images showed that the surface of the Antarctic sea ice is similar layer above it. There are mountains and valleys with varying heights. Unfortunately, the researchers did not launch the exact figure of the volume of ice in Antarctica based on three-dimensional image.

"For climate scientists, the ice thickness is a key determinant of changes in the system," said Jan Lieser, an expert in marine Antarctic glaciers. Numbers of sea ice thickness changes can be used to estimate the rate of change caused by global warming.

Ted Maksym, of the Woods Hole Oceanographic Institution in Massachusetts, said that Antarctica is very different from the Arctic. Arctic sea ice blocks open a landlocked, while the Antarctic is a continent surrounded by great seas. Amount of sea ice in the Arctic ocean is governed by temperature and the surrounding air. In the Antarctic, anginlah cause. The researchers believe that climate change is creating a kind of "wind wall" that traps cold weather only in Antarctica.

"Changes in the strength and direction of the wind over the last decade encouraging land ice farther out to sea," said Maksym. *** [NASA | NEWSCIENTIST | DAILYMAIL | MAHABDIKA SATRIA HADI | KORAN TEMPO 4034]
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