The frequency of intense hurricanes in the Atlantic Ocean appears to be closely connected to long-term trends in the El Niño/Southern Oscillation (ENSO) and the West African monsoon, according to new research from the Woods Hole Oceanographic Institution (WHOI). Geologists Jeff Donnelly and Jonathan Woodruff made that discovery while assembling the longest-ever record of hurricane strikes in the Atlantic basin.
Donnelly and Woodruff began reconstructing the history of land-falling hurricanes in the Caribbean in 2003 by gathering sediment-core samples from Laguna Playa Grande on Vieques (Puerto Rico), an island extremely vulnerable to hurricane strikes. They examined the cores for evidence of storm surges - distinctive layers of coarse-grained sands and bits of shell interspersed between the organic-rich silt usually found in lagoon sediments - and pieced together a 5,000-year chronology of land-falling hurricanes in the region.
In examining the record, they found large and dramatic fluctuations in hurricane activity, with long stretches of frequent strikes punctuated by lulls that lasted many centuries. The team then compared their new hurricane record with existing paleoclimate data on El Niño, the West African monsoon, and other global and regional climate influences. They found the number of intense hurricanes (category 3, 4, and 5 on the Saffir-Simpson scale) typically increased when El Niño was relatively weak and the West African monsoon was strong.
Science & Technology
The poet Dylan Thomas wrote, "The force that drives the green fuse drives the flower." Now, a team of international scientists has unlocked some of the secrets of that force: it has described the rules that govern how plants arrange flowers into branching structures, known in technical terms as 'inflorescences.' Nature has literally thousands of examples of inflorescences, which include the flower clusters of Mountain Ash, the tiny filigreed blossoms on Lilac and the stalkier inflorescences in Fireweed.
Published in the May 24 online edition of the journal Science, the team's paper outlines the mathematical model, molecular genetics and evolutionary processes that work together to create inflorescences as different as Forget-Me-Not and Snapdragon.
"This is a unifying theory that provides an explanation for the diversity of inflorescences we see in nature," says Dr. Przemyslaw Prusinkiewicz, the paper's lead author and a University of Calgary computer scientist. "It was thought that separate mechanisms explained the many differences in form and development of inflorescences in nature, but now we see that these are just facets of the same mechanism."
Published in the May 24 online edition of the journal Science, the team's paper outlines the mathematical model, molecular genetics and evolutionary processes that work together to create inflorescences as different as Forget-Me-Not and Snapdragon.
"This is a unifying theory that provides an explanation for the diversity of inflorescences we see in nature," says Dr. Przemyslaw Prusinkiewicz, the paper's lead author and a University of Calgary computer scientist. "It was thought that separate mechanisms explained the many differences in form and development of inflorescences in nature, but now we see that these are just facets of the same mechanism."
You might call it a tale of "monkey see, monkey do." Researchers at Ohio University have found that after primates evolved the ability to see red, they began to develop red and orange skin and hair.
Humans, apes and Old World monkeys, such as macaques and leaf monkeys, all have trichromatic vision, which allows these primates to distinguish between blue, green and red colors. Primatologists have disagreed about whether this type of color vision initially evolved to help early primates forage for ripe fruit and young, red leaves among green foliage or evolved to help them select mates.
Now a new study published online this week in American Naturalist by Ohio University researchers André Fernandez and Molly Morris rules out an initial advantage for mating and suggests that red-color vision evolved for non-social purposes, possibly foraging. But once developed, trichromaticism drove the evolution of red skin and hair through sexual selection.
Humans, apes and Old World monkeys, such as macaques and leaf monkeys, all have trichromatic vision, which allows these primates to distinguish between blue, green and red colors. Primatologists have disagreed about whether this type of color vision initially evolved to help early primates forage for ripe fruit and young, red leaves among green foliage or evolved to help them select mates.
Now a new study published online this week in American Naturalist by Ohio University researchers André Fernandez and Molly Morris rules out an initial advantage for mating and suggests that red-color vision evolved for non-social purposes, possibly foraging. But once developed, trichromaticism drove the evolution of red skin and hair through sexual selection.
Enormous sound waves seen rippling through a galaxy cluster are heating up its gas, new observations suggest. This may solve a longstanding puzzle about why such clusters refuse to cool down.
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| ©University of Cambridge - Chandra Observatory |
| Sound waves ripple through a galaxy cluster in this image from the Chandra X-ray Observatory. Bright x-rays from the gas near the centre has been filtered out to make the ripples more visible |
Twenty two years ago, safety concerns closed Tennessee Valley's the Browns Ferry nuclear power plant. After 8.1 billion dollars and one day's operation it is closing again.
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| ©Tennessee Valley Authority |
| Terminally ill Brown's Ferry nucleaer reactor |
Plasma astrophysicists at the University of Warwick have found that key information about the Sun's 'storm season' is being broadcast across the solar system in a fractal snapshot imprinted in the solar wind. This research opens up new ways of looking at both space weather and the unstable behaviour that affects the operation of fusion powered power plants.
Fractals, mathematical shapes that retain a complex but similar patterns at different magnifications, are frequently found in nature from snowflakes to trees and coastlines. Now Plasma Astrophysicists in the University of Warwick's Centre for Fusion, Space and Astrophysics have devised a new method to detect the same patterns in the solar wind.
The researchers, led by Professor Sandra Chapman, have also been able to directly tie these fractal patterns to the Sun's 'storm season'. The Sun goes through a solar cycle roughly 11 years long. The researchers found the fractal patterns in the solar wind occur when the Sun was at the peak of this cycle when the solar corona was at its most active, stormy and complex - sunspot activity, solar flares etc. When the corona was quieter no fractal patterns were found in the solar wind only general turbulence.
Fractals, mathematical shapes that retain a complex but similar patterns at different magnifications, are frequently found in nature from snowflakes to trees and coastlines. Now Plasma Astrophysicists in the University of Warwick's Centre for Fusion, Space and Astrophysics have devised a new method to detect the same patterns in the solar wind.
The researchers, led by Professor Sandra Chapman, have also been able to directly tie these fractal patterns to the Sun's 'storm season'. The Sun goes through a solar cycle roughly 11 years long. The researchers found the fractal patterns in the solar wind occur when the Sun was at the peak of this cycle when the solar corona was at its most active, stormy and complex - sunspot activity, solar flares etc. When the corona was quieter no fractal patterns were found in the solar wind only general turbulence.
Researchers at the Albert Einstein College of Medicine (AEC) have found evidence that certain fungi possess another talent beyond their ability to decompose matter: the capacity to use radioactivity as an energy source for making food and spurring their growth.
Detailing the research in Public Library of Science ONE, AEC's Arturo Casadevall said his interest was piqued five years ago when he read about how a robot sent into the still-highly-radioactive Chernobyl reactor had returned with samples of black, melanin-rich fungi that were growing on the ruined reactor's walls. "I found that very interesting and began discussing with colleagues whether these fungi might be using the radiation emissions as an energy source," explained Casadevall.
Detailing the research in Public Library of Science ONE, AEC's Arturo Casadevall said his interest was piqued five years ago when he read about how a robot sent into the still-highly-radioactive Chernobyl reactor had returned with samples of black, melanin-rich fungi that were growing on the ruined reactor's walls. "I found that very interesting and began discussing with colleagues whether these fungi might be using the radiation emissions as an energy source," explained Casadevall.
The remains of a wealthy Roman man, buried 1,600 years ago near London's St. Martin-in-the-Fields church, is providing clues for archaeologists trying to understand a little-known period in the city's history.
The remains of the man, who was in his early 40s when he died about A.D. 410, went on display yesterday at the Museum of London. The museum also is showing items found in tombs nearby that date from a period when the Saxons of northern Germany ruled the city.
The remains of the man, who was in his early 40s when he died about A.D. 410, went on display yesterday at the Museum of London. The museum also is showing items found in tombs nearby that date from a period when the Saxons of northern Germany ruled the city.
Researchers from the University of Texas have discovered a multi-planet system around an unexpected star, which they say could alter planet formation theories.
Astronomers William Cochran and Michael Endl, using the 9.2-meter Hobby-Eberly Telescope (HET) at McDonald Observatory discovered a system of two Jupiter-like planets orbiting a star whose composition seemed at odd with planet formation theories.
Astronomers William Cochran and Michael Endl, using the 9.2-meter Hobby-Eberly Telescope (HET) at McDonald Observatory discovered a system of two Jupiter-like planets orbiting a star whose composition seemed at odd with planet formation theories.
A massive crater in Northern Quebec has been luring the curious for over 50 years. Diamond prospectors, Second World War pilots and National Geographic all made pilgrimages to the distant natural wonder.
Now, an international team led by Laval University in Quebec City has journeyed to the Pingualuit Crater near the Hudson Strait in hopes of unlocking 120,000 years worth of secrets about climate change.
Now, an international team led by Laval University in Quebec City has journeyed to the Pingualuit Crater near the Hudson Strait in hopes of unlocking 120,000 years worth of secrets about climate change.
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| ©Michel Bouchard |
| Pingualuit Crater located on the Ungava Peninsula in northern Quebec. |
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