Science News Digest - 29th August 2012
In the science news this week, a satellite survey reveals record loss of Arctic sea ice, ants are to be fitted with radio backpacks, the first man on the Moon dies at age 82, and finally… new images show the position and intensity of every hurricane ever recorded.
Arctic sea ice reaches a record low
A satellite survey by NASA has revealed that the Arctic has lost more of its sea ice this summer than at any other time since satellite records began in 1979, reported the BBC.
The survey, run by NASA, shows that the sea ice is just 1.58 million sq miles (4.1 million sq km), compared to the previous low of 1.61 million square miles (4.17 sq km) on 18 September 2007.
This surface area is likely to reduce further, however, as the lowest point is usually in September.
The ice cap goes through a natural annual ebb and flow as the seasons change, but over the past three decades, satellites have observed a 13% decline per decade in the summer minimum.
The thickness of the sea ice is also declining, so the volume of ice has fallen even further, although estimates vary about the actual figure.
Joey Comiso, senior research scientist at NASA’s Goddard Space Flight Center, explained that this year’s ice decline has been caused by the warm temperatures of previous years, which reduced the amount of perennial ice – ice that is more resistant to melting.
"Unlike 2007, temperatures were not unusually warm in the Arctic this summer. [But] we are losing the thick component of the ice cover," he said. "And if you lose [that], the ice in the summer becomes very vulnerable."
Walt Meier, at the National Snow and Ice Data Center, works with NASA to analyse the data, said: "In the context of what's happened in the last several years and throughout the satellite record, it's an indication that the Arctic sea ice cover is fundamentally changing."
Professor Peter Wadhams, from Cambridge University, told BBC News: "A number of scientists who have actually been working with sea ice measurement had predicted some years ago that the retreat would accelerate and that the summer Arctic would become ice-free by 2015 or 2016.
"I was one of those scientists - and of course bore my share of ridicule for daring to make such an alarmist prediction."
But he believes that that prediction is now becoming true, and the ice cap has become so thin in places that it would inevitably disappear.
"Measurements from submarines have shown that it has lost at least 40% of its thickness since the 1980s, and if you consider the shrinkage as well it means that the summer ice volume is now only 30% of what it was in the 1980s," he added.
"This means an inevitable death for the ice cover, because the summer retreat is now accelerated by the fact that the huge areas of open water already generated allow storms to generate big waves which break up the remaining ice and accelerate its melt.
"Implications are serious: the increased open water lowers the average albedo [reflectivity] of the planet, accelerating global warming; and we are also finding the open water causing seabed permafrost to melt, releasing large amounts of methane, a powerful greenhouse gas, to the atmosphere."
Ants wear radio backpacks to keep track of colony
One thousand ants from a site on Longshaw Estate in Derbyshire will be fitted with tiny radio backpacks to monitor their social interactions in their colonies, reported The Telegraph.
The hairy wood ants, an internationally protected species, will be fitted with radio receivers that are just one millimetre long. This is the first time a project like this has been attempted, and the aim is to discover more about the way that they communicate and travel within their colonies.
The receiver will not interfere or harm the ants in any way, and can be fitted on the ants in a few seconds.
The findings will be used by National Trust staff on the estate to manage the woodland where the ants are found.
It has also been suggested that the information could be used to inform the development of social networking sites, like Facebook and Twitter, because the ants are so efficient at communicating information with a minimum amount of movement.
Samuel Ellis, a biologist from University of York, who are running the project, said that: “This research is about trying to find out how the ants communicate and commute between the vast network of nests and how they travel in this environment.
“The radio receivers act like a barcode to mark out each individual ant. A single ant is not particularly clever but is part of an elaborate system that is clearly performing very effectively at Longshaw.
“The way the ants use this network has important implications for how they interact with their environment. And the way information is passed through the network may even have implications for our information and telecommunications networks.”
Neil Armstrong, the first man on the Moon, dies at the age of 82
Neil Armstrong, the first man to walk on the moon, has died at the age of 82, after heart complications following surgery, reported The Guardian.
He was the commander of the Apollo 11 mission, the first manned spacecraft to touchdown on the surface of the Moon, on July 20, 1969. He was the first person to set foot on the Moon, and spoke the now infamous words: “That’s one small step for man, one giant leap for mankind.”
Armstrong underwent heart bypass surgery at the beginning of August to relieve blocked arteries. His family released a statement on Saturday to announce his passing.
It read: "We are heartbroken to share the news that Neil Armstrong has passed away following complications resulting from cardiovascular procedures. Neil was our loving husband, father, grandfather, brother and friend. Neil Armstrong was also a reluctant American hero who always believed he was just doing his job. He served his nation proudly as a Navy fighter pilot, test pilot, and astronaut.
"While we mourn the loss of a very good man we also celebrate his remarkable life and hope that it serves as an example to young people around the world to work hard to make their dreams come true, to be willing to explore and push the limits, and to selflessly serve a cause greater than themselves."
Map of every hurricane ever recorded
A data visualisation expert has created a map showing the location and intensity of every hurricane and tropical storm recorded since 1851. The data, collected by the US National Oceanic and Atmospheric Administration (NOAA), incorporates more than 12,000 data points.
Reported in New Scientist, the map shows an unusual view of the Earth with the centre of the map on the South Pole. John Nelson who created the map explained on his blog that he felt that viewing the Earth from that angle represented the patterns underlying hurricane formation in the most interesting way. It’s hard to decipher, but once you do, it makes a lot of sense.