May 12, 2014 - SOUTH POLE - Winds in the wild Southern Ocean are blowing at their strongest in a millennia as climate change shifts weather patterns, leaving Antarctica colder and Australia facing more droughts, a study showed Monday.
Rising carbon dioxide levels in the atmosphere were strengthening the winds, already dubbed the "Roaring Forties" for their ferocity, and pushing them further south towards Antarctica, researchers from the Australian National University (ANU) said.
"The Southern Ocean winds are now stronger than at any other time in the past 1,000 years," said the study's lead researcher Nerilie Abram of an ocean notorious for having some of the fiercest winds and largest waves on the planet.
"The strengthening of these winds has been particularly prominent over the past 70 years, and by combining our observations with climate models we can clearly link this to rising greenhouse gas levels."
The new research, which was published in the Nature Climate Change journal, explains why Antarctica is not warming as much as other continents.
The westerly winds, which do not touch the eastern parts of Antarctica but circle in the ocean around it, were trapping more of the cold air over the area as they strengthened, with the world's southernmost continent "stealing more of Australia's rainfall", Abram said.
"This is why Antarctica has bucked the trend. Every other continent is warming, and the Arctic is warming fastest of anywhere on earth," she said.
The study's authors analysed ice cores from Antarctica, along with data
from tree rings and lakes in South America, using the southern
hemisphere's most powerful supercomputer "Raijin", which is based at the
ANU.
The research helped to explain why the westerlies were further cooling already cold parts of the continent even as they were also driving "exceptionally quicker" warming in the Antarctic Peninsula, which juts out into their path, Abram said.
The strengthening westerlies drive up the temperature at the peninsula -- the only part of the Antarctica that is hit by the wind -- through the warm, moist air they carry from the Southern Ocean.
This has made the peninsula the fastest-warming place in the southern hemisphere, with scientists concerned about the stability of the ice sheets and sea level rises in the region.
The shift in the westerlies -- approximately 200 kilometres in the 20th century -- was driven by human emissions of carbon dioxide, said research fellow Steven Phipps of the University of New South Wales, who worked on the climate modelling used in the study.
From the 1970s, the shift was exacerbated by the expanding ozone hole caused by human emissions of chlorofluorocarbons (CFCs), Phipps added.
"Even for a mid-range climate scenario, the trend is going to continue in the 21st century," Phipps said, adding that southern Australia was likely to experience more dry winters. - AFP.
Antarctic sea ice has expanded to record levels for April, increasing by more than 110,000sq km a day last month to nine million square kilometres.
The National Snow and Ice Data Centre said the rapid expansion had continued into May and the seasonal cover was now bigger than the record "by a significant margin''.
"This exceeds the past record for the satellite era by about 320,000sq km, which was set in April 2008,'' the centre said.
Here are some current plots of Antarctic Sea Ice from the WUWT Sea Ice Page
Increased ice cover in Antarctic continues to be at odds with falling Arctic ice levels, where the summer melt has again pushed levels well below the average extent for 1981-2010. The centre said while the rate of Arctic-wide retreat was rapid through the first half of April, it had slowed.
The April Arctic minimum was 270,000sq km higher than the record April low, which occurred in 2007. The Antarctic sea ice extent anomalies were greatest in the eastern Weddell and along a long stretch of coastline south of Australia and the southeastern Indian Ocean. The centre said the increased ice extent in the Weddell Sea region appeared to be associated with a broad area of persistent easterly winds in March and April, and lower-than-average temperatures. - WUWT.
Southern Ocean Wind Blows Hardest In 1,000 Years
![]() |
| Antarctica winds |
Rising carbon dioxide levels in the atmosphere were strengthening the winds, already dubbed the "Roaring Forties" for their ferocity, and pushing them further south towards Antarctica, researchers from the Australian National University (ANU) said.
"The Southern Ocean winds are now stronger than at any other time in the past 1,000 years," said the study's lead researcher Nerilie Abram of an ocean notorious for having some of the fiercest winds and largest waves on the planet.
"The strengthening of these winds has been particularly prominent over the past 70 years, and by combining our observations with climate models we can clearly link this to rising greenhouse gas levels."
The new research, which was published in the Nature Climate Change journal, explains why Antarctica is not warming as much as other continents.
The westerly winds, which do not touch the eastern parts of Antarctica but circle in the ocean around it, were trapping more of the cold air over the area as they strengthened, with the world's southernmost continent "stealing more of Australia's rainfall", Abram said.
"This is why Antarctica has bucked the trend. Every other continent is warming, and the Arctic is warming fastest of anywhere on earth," she said.
![]() |
| Image: Earth.nullschool.ne |
The research helped to explain why the westerlies were further cooling already cold parts of the continent even as they were also driving "exceptionally quicker" warming in the Antarctic Peninsula, which juts out into their path, Abram said.
The strengthening westerlies drive up the temperature at the peninsula -- the only part of the Antarctica that is hit by the wind -- through the warm, moist air they carry from the Southern Ocean.
This has made the peninsula the fastest-warming place in the southern hemisphere, with scientists concerned about the stability of the ice sheets and sea level rises in the region.
The shift in the westerlies -- approximately 200 kilometres in the 20th century -- was driven by human emissions of carbon dioxide, said research fellow Steven Phipps of the University of New South Wales, who worked on the climate modelling used in the study.
From the 1970s, the shift was exacerbated by the expanding ozone hole caused by human emissions of chlorofluorocarbons (CFCs), Phipps added.
"Even for a mid-range climate scenario, the trend is going to continue in the 21st century," Phipps said, adding that southern Australia was likely to experience more dry winters. - AFP.
Antarctic Sea Ice At Record Levels For April And It Continues In May
![]() |
| National Snow & Ice Data Center (NSIDC) |
Antarctic sea ice has expanded to record levels for April, increasing by more than 110,000sq km a day last month to nine million square kilometres.
The National Snow and Ice Data Centre said the rapid expansion had continued into May and the seasonal cover was now bigger than the record "by a significant margin''.
"This exceeds the past record for the satellite era by about 320,000sq km, which was set in April 2008,'' the centre said.
Here are some current plots of Antarctic Sea Ice from the WUWT Sea Ice Page
![]() |
| Antarctic Sea Ice Extent – 15% or Greater. National Snow & Ice Data Center (NSIDC) |
![]() |
| Southern Hemisphere Sea Ice Extent With Anomaly |
![]() |
| Southern Hemisphere Sea Ice Area Anomaly. Cryosphere Today – Arctic Climate Research at the University of Illinois |
Increased ice cover in Antarctic continues to be at odds with falling Arctic ice levels, where the summer melt has again pushed levels well below the average extent for 1981-2010. The centre said while the rate of Arctic-wide retreat was rapid through the first half of April, it had slowed.
The April Arctic minimum was 270,000sq km higher than the record April low, which occurred in 2007. The Antarctic sea ice extent anomalies were greatest in the eastern Weddell and along a long stretch of coastline south of Australia and the southeastern Indian Ocean. The centre said the increased ice extent in the Weddell Sea region appeared to be associated with a broad area of persistent easterly winds in March and April, and lower-than-average temperatures. - WUWT.




































