Record Depletion of Arctic Ozone Layer Causing Increased UV Radiation in Scandinavia

Over the past few days ozone-depleted air masses extended from the north pole to southern Scandinavia leading to higher than normal levels of ultraviolet (UV) radiation during sunny days in southern Finland. These air masses will move east over the next few days, covering parts of Russia and perhaps extend as far south as the Chinese/Russian border. Such excursions of ozone-depleted air may also occur over Central Europe and could reach as far south as the Mediterranean.

At an international press conference by the World Meteorological Organisation (WMO) in Vienna April 5, atmospheric researcher Dr. Markus Rex from Germany´s Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association (AWI) pointed out that the current situation in the Arctic ozone layer is unparalleled.

"Such massive ozone loss has so far never occurred in the northern hemisphere, which is densely populated even at high latitudes," AWI researcher Markus Rex describes the situation. The ozone layer protects life on Earth's surface from harmful solar ultraviolet radiation. Because of the low inclination angle of the sun, exposure to ultraviolet radiation is not normally a public health concern at high northern latitudes. However, if ozone-depleted air masses drift further south over Central Europe, south Canada, the US, or over Central Asiatic Russia, for example, the surface intensity of UV radiation could lead to sunburn within minutes for sensitive persons, even in April.

Whether and when this may occur can be forecasted reliably only in the short term. People should thus follow the UV forecasts of regional weather services. "If elevated levels of surface UV occur, they will last a few days and sun protection will be necessary on those days, especially for children," Rex recommends.

The expected UV intensity during these short episodes will, however, remain in the range of typical exposure at the height of summer and below the values that occur during holiday trips to the tropics. Extreme caution is therefore unnecessary. "The concern is that people don't expect to get sunburn so rapidly early in the year and consequently don't take sun protection as seriously as in the middle of summer or while on vacation," states Rex. Any sunburn increases the risk of developing skin cancer later in life and this adverse effect is particularly pronounced in children.

"But provided that UV-protection is used it is safe and even healthy to exercise normal outdoor activities even during low ozone episodes. Particularly in countries high up in the north people tend to suffer from vitamin D deficit after the dark winter and Sun is a natural source of it," adds Dr. Esko Kyrö from Arctic Research Center at Finnish Meteorological Institute.

The air masses with very low ozone concentrations will eventually disperse, as the sun warms the stratosphere and the winds change, as happens every year in spring. This will lead to somewhat lower ozone in spring and early summer this year, as the low ozone from the Arctic mixes with other stratospheric air throughout the northern hemisphere. This effect will be small, due to the large dilution of the ozone depleted air masses in background air.

As noted some weeks ago, the Arctic stratosphere has been unusually cold this winter, resulting in a transformation of chlorine supplied by industrial compounds into other forms that aggressively remove ozone. Since then the ozone removal process gained additional momentum by the return of sunlight to the Arctic, which is needed for the chemical processes to occur. The current amount of ozone depletion above the Arctic is far beyond that recorded for any other spring, over the time when ozone has been measured by modern instrumentation. These findings are based on an international network of 30 ozone sounding stations in the Arctic and Subarctic that is coordinated by the Alfred Wegener Institute.

Background

This year's Arctic ozone depletion is caused by industrial CFCs and related compounds. Production of these chemicals was banned by the Montreal Protocol. Ozone loss was particularly large this winter due to unusually low temperature, which results in the presence of clouds in the polar stratosphere. Reactions on the surface of these clouds transform chlorine containing breakdown products of CFCs into compounds that aggressively remove ozone. Even though the Montreal Protocol has successfully banned the production of CFCs and related compounds, chlorine levels in the Arctic stratosphere are only about 5% below the prior peak level, due to the long atmospheric lifetime of CFCs (removal takes 50 to 100 years). The Arctic ozone layer will remain vulnerable to depletion for the next several decades, particularly following unusually cold winters. In contrast, temperatures within the Antarctic stratosphere are cold enough, each winter, to lead to widespread occurrence of stratospheric clouds that are part of the chain of events that causes the Antarctic ozone hole that occurs each spring.

The stratosphere has been observed to cool, following the rise of greenhouse gases (GHGs), because heat that would otherwise reach the stratosphere is trapped below, warming the surface. The situation for the Polar Stratosphere is more complicated because of dynamical heating by waves generated in frontal systems. For several years, however, scientists have noted that the coldest winters in the Arctic stratosphere are getting colder, a development that enhances the ozone-destroying efficiency of the remaining CFCs and could be linked to rising levels of GHGs. "The current winter is a striking continuation of this tendency. Hence, we are not surprised by the fact that such massive ozone depletion has now occurred above the Arctic," says Rex. "Determining the role that GHG driven climate change might play for Arctic ozone loss is a great challenge and the subject of on-going research throughout the international atmospheric sciences community" states Ross Salawitch of the University of Maryland. The European Union contributes to financing this research in the RECONCILE project, a 3.5 million euro research programme in which 16 research institutions from eight European countries are working towards improved understanding of the Arctic ozone layer.

"On the basis of internationalagreements on protection of the ozone layer, the specifically the Montreal Protocol and its amendments, we expect, however, that ozone depletion due to CFCs will finally become passé towards the end of the century. This is an impressive success of international environmental policy under the umbrella of the United Nations. This success is only temporarily clouded by the record ozone loss above the Arctic this year," says Rex. For several decades, however, the fate of the Arctic ozone layer each spring will be closely linked to the evolution of temperatures in the polar stratosphere.

King Henry VIII's Madness Explained

Henry VIII may have had two rare medical conditions that could explain both his health issues later in life and the miscarriages of two of his wives.
An X-linked genetic disease might have caused Henry to become paranoid and anxious after his 40th birthday.
An unusual blood type might have caused the bodies of his wives to attack their fetuses.

Among a long list of personality quirks and historical drama, Henry VIII is known for the development of health problems in mid-life and a series of miscarriages for two of his wives. In a new study, researchers propose that Henry had an X-linked genetic disorder and a rare blood type that could explain many of his problems.

By suggesting biological causes for significant historical events, the study offers new ways to think about the infamous life of the notorious 16th-century British monarch, said Catarina Whitley, a bioarchaeologist who completed the research while at Southern Methodist University.

"What really made us look at Henry was that he had more than one wife that had obstetrical problems and a bad obstetrical history," said Whitley, now with the Museum of New Mexico. "We got to thinking: Could it be him?"

Plenty of historians have written about Henry's health problems. As a young man, he was fit and healthy. But by the time of his death, the King weighed close to 400 pounds. He had leg ulcers, muscle weakness, and, according to some accounts, a significant personality shift in middle age towards more paranoia, anxiety, depression and mental deterioration.

Among other theories, experts have proposed that Henry suffered from Type II diabetes, syphilis, an endocrine problem called Cushing's syndrome, or myxedema, which is a byproduct of hypothyroidism.

All of those theories have flaws, Whitley said, and none address the monarch's reproductive woes. Two of his six wives -- Ann Boleyn and Katherine of Aragon -- are thought to have suffered multiple miscarriages, often in the third trimester.

To explain those patterns, Whitley and colleague Kyra Kramer offer a new theory: Henry may have belonged to a rare blood group, called Kell positive. Only 9 percent of the Caucasian population belongs to this group.

When a Kell positive man impregnates a Kell negative woman, there is a 50 percent chance of provoking an immune response in the woman's body that attacks her developing fetus. The first baby of a Kell positive father and Kell negative mother is usually fine. But some of the baby's blood will inevitably get into the mother's body -- either during development or at birth, leading her to produce antibodies against the baby's Kell antigens.

As a result, in subsequent pregnancies, babies may suffer from extra fluid in their tissues, anemia, jaundice, enlarged spleens, or heart failure, often leading to miscarriage between about 24 and 28 weeks of pregnancy.

Ann Boleyn is a classic example of this pattern, Whitley said. According to some accounts (and there is still much dispute about the details, including how many pregnancies there actually were), Elizabeth -- Anne's first daughter with Henry -- was born healthy and without complications. But her second and third pregnancies miscarried at about month six or seven.

Katherine of Aragon carried as many as six pregnancies. Only her fifth led to the birth of a live and health baby, a daughter named Mary.

In addition to Henry's problematic blood type, the researchers propose that he also had a rare genetic disorder called McLeod syndrome. Carried on the X-chromosome, the disease generally affects only men and usually sets in around age 40 with symptoms including heart disease, movement disorders and major psychological symptoms, including paranoia and mental decline.

The disease could explain many of Henry's physical ailments, the researchers propose. It could also explain why he may have become more despotic as he grew older and why he shifted from supporting Anne to having her beheaded.

"This gives us an alternative way of interpreting Henry and understanding his life," Whitley said. "It gives us a new way to look at the reasons he changed."

Without any genetic evidence, however, there's no way to know for sure whether the new theories are right, said Retha Warnicke, a historian at Arizona State University and author of The Rise and Fall of Anne Boleyn: Family Politics at the Court of Henry VIII.

Other conditions could explain the miscarriages, she said. Until the late 19th-century, midwives did not wash their hands. And in Henry's time, up to half of all children died before age 15.

As for Henry's woes, dementia could explain his personality shifts, she added. Lack of exercise -- after an active youth -- combined with a hearty appetite could have led to his obesity and related ills.

"Could is the big word," Warnicke said. "It's an interesting theory and it's possibly true, but it can't be proven without some clinical evidence, and there is none."

The Day the Earth Sped Up

The massive earthquake that hit Japan sped up Earth's spin by a microsecond and tilted the axis by several inches.
The shift happened when massive amounts of the planet's crust tumbled inside a 250-mile long crack that opened up six miles beneath the Pacific Ocean.
Changes in Earth's tilt are associated with ice ages.

This weekend, it wasn't just the shift to Daylight Saving's Time that reset our clocks. Mother Nature tweaked time by speeding up Earth's spin a bit in response to the killer earthquake that rocked Japan on Friday.

"There was a redistribution of an enormous amount of the Earth's crust," theoretical physicist Michio Kaku, with the City College of New York, told Discovery News. "It actually shortened the time of the day, and also shifted the axis of the Earth."

The 8.9-magnitude quake -- the fifth largest in recorded history -- shaved about one-millionth of second off our day and tilted the planet's axis by several inches.

Looking to help the victims of the disaster in Japan? Make your contribution to GlobalGiving's relief fund here.

Kaku says the phenomenon is similar to what happens when a dancer folds in his or her arms and speeds up in a spin.

The shifting of tectonic plates beneath the Pacific Ocean opened up a crack about 250 miles long, causing a good portion of Earth's crust to tumble inside.

"We know how much the Earth contracted as consequence of that, then you do the math," Kaku said.

While the speeding up of Earth isn't expected to have any immediate or long term impacts, the tilt of the axis might.

"There is still a scientific debate as to what causes ice ages," Kaku said. "The leading theory is that there are tiny perturbations in the axis of the Earth as it turns around the sun that accumulate with time. These small shifts, this wobbling of the axis of the Earth may in fact cause ice ages."

"Every century, we have several of these monster earthquakes so it's hard to estimate exactly how much of an impact this earthquake would have on an ice age, for example," Kaku added.

The earthquake was the most powerful to hit Japan since official record-keeping began in late 1800s, says the U.S. Geological Survey.

It struck about 80 miles off Japan's east coast, roughly 240 miles northeast of Tokyo, at a depth of six miles. The death toll from the earthquake, a massive tsunami that followed, and an ongoing serious of aftershocks is expected to reach in the thousands.

Alligator Gar

The prehistoric relatives of this megafish inhabited many parts of the world, but today gars live only in North and Central America.

Of the seven known gar species, the alligator is the largest, reaching up to ten feet (three meters) long and tipping the scales at up to 300 pounds (140 kilograms). These menacing-looking behemoths are generally olive green or yellow and have a heavily scaled body. A tooth-filled mouth and wide, alligator-like snout give the species its name.

These freshwater giants may look fierce, but attacks against people are unknown. They can pose a passive danger, though—the fish's eggs are poisonous to humans if ingested.

Adult gars have few natural predators, although alligators have been known to attack them. Young are preyed upon by larger fish. Alligator gars prey on fish, but they are opportunistic and have been known to feed on everything from waterfowl and small turtles to carrion.

Alligator gars are found throughout much of the coastal U.S. Southeast. They inhabit waters as far west as Texas and Oklahoma, as far north as the Mississippi River Basin and the lower Ohio and Missouri river systems, and southern drainages well into Mexico.

Gars inhabit lakes, bayous, and bays and are able to tolerate brackish and even salt water. But these toothy giants prefer large, slow-moving rivers, particularly those with wide floodplains, where shallow waters provide hatchlings with some protection from predators.

Unfortunately for the alligator gar, flood-control measures such as dams and dikes have dramatically altered their riverine ecosystems and largely eliminated their preferred spawning habitats across North America. These breeding challenges have contributed to significant population declines across much of the animal's range.

Alligator gars are also targeted by both commercial and sport fisheries and have frequently been overfished. They are now protected by law in parts of their range.

Lifelike "Wet Mummy" Found During Roadbuilding

With eyebrows, hair, and skin still intact after more than 600 years, a remarkably preserved Chinese "wet mummy" remains bundled in her quilt after centuries in a flooded coffin.

Removed from her wooden casket on March 1, the body had been found in a tomb accidentally uncovered by roadbuilders near the city of Taizhou (map).

"Wet mummies survive so well because of the anaerobic conditions of their burials," said archaeologist Victor Mair. That is, water unusually void of oxygen inhibits bacteria that would normally break down a body.

Unlike ancient Egyptian mummies, the corpse—likely from the Ming dynasty (1368 to 1644)—was probably preserved only accidentally, said Mair, of the University of Pennsylvania.

"I don't know of any evidence that Chinese ever intentionally mummified their deceased," he said. "Whoever happened to encounter the right environment might become a preserved corpse."



Red-Glove Service

Photograph by Gu Xiangzhong, Xinhua/Corbis

Staff members from China's Taizhou Museum carefully raise the mummy—one of three found during a road expansion—from her wooden coffin on March 1.

The fully dressed, 5-foot-long (1.5-meter-long) body was buried with luxury items, including a jade ring, a silver hairpin, and more than 20 pieces of Ming-dynasty clothing.

The lack of identifying insignia such as a phoenix or dragon, though, suggests the wet mummy wasn't royal, said Timothy Brook, a historian at the University of British Columbia's Institute of Asian Research.

"Her headgear is sort of ordinary," Brook said. "There's nothing that sets her apart from anyone else. ... She was probably just a well-off person."


You Can't Take It With You?

Photograph by Gu Xiangzhong, Xinhua/Corbis

A worker from the Taizhou Museum cleans the Chinese wet mummy's large jade ring on March 3.

Jade was associated with longevity in ancient China. But in this case, the jade ring was "probably a sign of her wealth instead of a sign of any concern about the afterlife," Brook said.


Good Hair Day

Photograph by Gu Xiangzhong, Xinhua/Corbis

A museum worker removes the female mummy's cap on March 3, revealing hair held in place by a still bright silver hairpin—a fairly standard example of the type worn by Ming-dynasty women, Brook said.

Neither Brook nor the University of Pennsylvania's Mair know why the wet mummy's head appears dyed purple beneath her cap, though Mair speculates it may have to do with natural minerals in the water.

The woman's age at death is unknown, but her unlined face suggests she was fairly young.

"She's certainly an adult," Brook said. "She's not an old woman."



Water Bed

Photograph from Barcroft/Fame Pictures

The newfound mummy rests on a plastic sheet after being removed from her flooded coffin on March 1.

In ancient China, it was believed that the newly dead would appear before supernatural judges.

"If you were found to be morally worthy," Brook explained, "you would be sent off for reincarnation—as a deity if you were fantastic, as a human being if you were good, as an animal if you were less good, and as a bug or a worm if you'd been really bad."


Submerged in the brownish liquid that likely preserved it, the Ming dynasty-era mummy lies in her wooden coffin prior to her removal on March 1.

The University of Pennsylvania's Mair thinks the liquid is oxygen-poor water that leaked into the coffin and not any type of special preservation fluid.



Exorcism Coin

Photograph by Gu Xiangzhong, Xinhua/Corbis

A so-called exorcism coin adorns the chest of the newfound Chinese "wet mummy."

"My guess would be that the coin was placed on the body as a kind of charm against malevolent influences," Brook said.

Still unknown is whether the woman was buried with any written documents or inscribed pottery—a common practice in Ming-dynasty China.

"If you were a person of any importance, you had someone write a [remembrance] or a brief biography," Brook said, "and that biography would often be posted at the burial site and a copy buried with you as well, to identify who you are" in the afterlife.

North America Safe From Radioactive Particles

Radioactive particles from the failing Fukushima Daiichi nuclear power station pose little immediate risk to North America, and should fall into the Pacific before reaching western shores.

Using a publicly available modeling system for airborne pollutants developed by the National Oceanic and Atmospheric Administration, Weather Underground’s Jeff Masters has modeled the spread of radioactive plumes. So far, the “great majority of these runs” have seen the plumes float over the Pacific, reaching eastern Siberia and the western coast of North America in about a week.

“Such a long time spent over water will mean that the vast majority of the radioactive particles will settle out of the atmosphere or get caught up in precipitation and rained out,” wrote Masters. “It is highly unlikely that any radiation capable of causing harm to people will be left in the atmosphere after seven days and 2000-plus miles of travel distance.”

A press release issued March 13 by the U.S. Nuclear Regulatory Commission echoed Masters’ speculation. “Given the thousands of miles between the two countries, Hawaii, Alaska, the U.S. Territories and the U.S. West Coast are not expected to experience any harmful levels of radioactivity,” (pdf) they announced.

Speed Demon Star Creates a Shock

Just as some drivers obey the speed limit while others treat every road as if it were the Autobahn, some stars move through space faster than others. NASA's Wide-field Infrared Survey Explorer, or WISE, captured this image of the star Alpha Camelopardalis, or Alpha Cam, in astronomer-speak, speeding through the sky like a motorcyclist zipping through rush-hour traffic. The supergiant star Alpha Cam is the bright star in the middle of this image, surrounded on one side by an arc-shaped cloud of dust and gas -- a bow shock -- which is colored red in this infrared view.
Such fast-moving stars are called runaway stars. The distance and speed of Alpha Cam is somewhat uncertain. It is probably somewhere between 1,600 and 6,900 light-years away and moving at an astonishing rate of somewhere between 680 and 4,200 kilometers per second (between 1.5 and 9.4 million mph). It turns out that WISE is particularly adept at imaging bow shocks from runaway stars. Previous examples can be seen around Zeta Ophiuchi , AE Aurigae, and Menkhib. But Alpha Cam revs things up into a different gear. To put its speed into perspective, if Alpha Cam were a car driving across the United States at 4,200 kilometers per second, it would take less than one second to travel from San Francisco to New York City!

Astronomers believe runaway stars are set into motion either through the supernova explosion of a companion star or through gravitational interactions with other stars in a cluster. Because Alpha Cam is a supergiant star, it gives off a very strong wind. The speed of the wind is boosted in the forward direction the star is moving in space. When this fast-moving wind slams into the slower-moving interstellar material, a bow shock is created, similar to the wake in front of the bow of a ship in water. The stellar wind compresses the interstellar gas and dust, causing it to heat up and glow in infrared. Alpha Cam's bow shock cannot be seen in visible light, but WISE's infrared detectors show us the graceful arc of heated gas and dust around the star.http://www.blogger.com/img/blank.gifhttp://www.blogger.com/img/blank.gif

JPL manages and operates the Wide-field Infrared Survey Explorer fohttp://www.blogger.com/img/blank.gifr NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu and http://jpl.nasa.gov/wise .

The Most Distant Mature Galaxy Cluster: Young, but Surprisingly Grown-Up

"We have measured the distance to the most distant mature cluster of galaxies ever found," says the lead author of the study in which the observations from ESO's VLT have been used, Raphael Gobat (CEA, Paris). "The surprising thing is that when we look closely at this galaxy cluster it doesn't look young -- many of the galaxies have settled down and don't resemble the usual star-forming galaxies seen in the early Universe."
Clusters of galaxies are the largest structures in the Universe that are held together by gravity. Astronomers expect these clusters to grow through time and hence that massive clusters would be rare in the early Universe. Although even more distant clusters have been seen, they appear to be young clusters in the process of formation and are not settled mature systems.

The international team of astronomers used the powerful VIMOS and FORS2 instruments on ESO's Very Large Telescope (VLT) to measure the distances to some of the blobs in a curious patch of very faint red objects first observed with the Spitzer space telescope. This grouping, named CL J1449+0856 [1], had all the hallmarks of being a very remote cluster of galaxies [2]. The results showed that we are indeed seeing a galaxy cluster as it was when the Universe was about three billion years old -- less than one quarter of its current age [3].

Once the team knew the distance to this very rare object they looked carefully at the component galaxies using both the NASA/ESA Hubble Space Telescope and ground-based telescopes, including the VLT. They found evidence suggesting that most of the galaxies in the cluster were not forming stars, but were composed of stars that were already about one billion years old. This makes the cluster a mature object, similar in mass to the Virgo Cluster, the nearest rich galaxy cluster to the Milky Way.

Further evidence that this is a mature cluster comes from observations of X-rays coming from CL J1449+0856 made with ESA's XMM-Newton space observatory. The cluster is giving off X-rays that must be coming from a very hot cloud of tenuous gas filling the space between the galaxies and concentrated towards the centre of the cluster. This is another sign of a mature galaxy cluster, held firmly together by its own gravity, as very young clusters have not had time to trap hot gas in this way.

As Gobat concludes: "These new results support the idea that mature clusters existed when the Universe was less than one quarter of its current age. Such clusters are expected to be very rare according to current theory, and we have been very lucky to spot one. But if further observations find many more then this may mean that our understanding of the early Universe needs to be revised."

Notes

[1] The strange name refers to the object's position in the sky.

[2] The galaxies appear red in the picture partly because they are thought to be mainly composed of cool, red stars. In addition the expansion of the Universe since the light left these remote systems has increased the wavelength of the light further so that it is mostly seen as infrared radiation when it gets to Earth.

[3] The astronomers measured the distance to the cluster by splitting the light up into its component colours in a spectrograph. They then compared this spectrum with one of a similar object in the nearby Universe. This allowed them to measure the redshift of the remote galaxies -- how much the Universe has expanded since the light left the galaxies. The redshift was found to be 2.07, which means that the cluster is seen about three billion years after the Big Bang.

NASA Study Goes to Earth's Core for Climate Insights

The latest evidence of the dominant role humans play in changing Earth's climate comes not from observations of Earth's ocean, atmosphere or land surface, but from deep within its molten core.
Scientists have long known that the length of an Earth day -- the time it takes for Earth to make one full rotation -- fluctuates around a 24-hour average. Over the course of a year, the length of a day varies by about 1 millisecond, getting longer in the winter and shorter in the summer. These seasonal changes in Earth's length of day are driven by exchanges of energy between the solid Earth and fluid motions of Earth's atmosphere (blowing winds and changes in atmospheric pressure) and its ocean. Scientists can measure these small changes in Earth's rotation using astronomical observations and very precise geodetic techniques.

But the length of an Earth day also fluctuates over much longer timescales, such as interannual (two to 10 years), decadal (approximately 10 years), or those lasting multiple decades or even longer. A dominant longer timescale mode that ranges from 65 to 80 years was observed to change the length of day by approximately 4 milliseconds at the beginning of the 20th century.

These longer fluctuations are too large to be explained by the motions of Earth's atmosphere and ocean. Instead, they're due to the flow of liquid iron within Earth's outer core, where Earth's magnetic field originates. This fluid interacts with Earth's mantle to affect Earth's rotation. While scientists cannot observe these flows directly, they can deduce their movements by observing Earth's magnetic field at the surface. Previous studies have shown that this flow of liquid iron in Earth's outer core oscillates, in waves of motion that last for decades with timescales that correspond closely to long-duration variations in Earth's length of day.

Still other studies have observed a link between the long-duration variations in Earth's length of day and fluctuations of up to 0.2 degrees Celsius (0.4 degree Fahrenheit) in Earth's long-term global average surface air temperature.

So how might all three of these variables -- Earth's rotation, movements in Earth's core (formally known as the core angular momentum) and global surface air temperature -- be related? That's what researchers Jean Dickey and Steven Marcus of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and colleague Olivier de Viron of the Universite Paris Diderot and Institut de Physique du Globe de Paris in France, set out to discover in a first-of-its-kind study.

The scientists mapped existing data from a model of fluid movements within Earth's core and data on yearly averaged length-of-day observations against two time series of observed annual global average surface temperature: one from NASA's Goddard Institute of Space Studies in New York that extends back to 1880, and another from the United Kingdom's Met Office that extends back to 1860. Since total air temperature is composed of two components -- temperature changes that occur naturally and those caused by human activities -- the researchers used results from computer climate models of Earth's atmosphere and ocean to account for temperature changes due to human activities. These human-produced temperature changes were then subtracted from the total observed temperature records to generate corrected temperature records.

The researchers found that the uncorrected temperature data correlated strongly with data on movements of Earth's core and Earth's length of day until about 1930. They then began to diverge substantially: that is, global surface air temperatures continued to increase, but without corresponding changes in Earth's length of day or movements of Earth's core. This divergence corresponds with a well-documented, robust global warming trend that has been widely attributed to increased levels of human-produced greenhouse gases.

But an examination of the corrected temperature record yielded a different result: the corrected temperature record remained strongly correlated with both Earth's length of day and movements of Earth's core throughout the entire temperature data series. The researchers performed robust tests to confirm the statistical significance of their results.

"Our research demonstrates that, for the past 160 years, decadal and longer-period changes in atmospheric temperature correspond to changes in Earth's length of day if we remove the very significant effect of atmospheric warming attributed to the buildup of greenhouse gases due to mankind's enterprise," said Dickey. "Our study implies that human influences on climate during the past 80 years mask the natural balance that exists among Earth's rotation, the core angular momentum and the temperature at Earth's surface."

So what mechanism is driving these correlations? Dickey said scientists aren't sure yet, but she offered some hypotheses.

Since scientists know air temperature can't affect movements of Earth's core or Earth's length of day to the extent observed, one possibility is the movements of Earth's core might disturb Earth's magnetic shielding of charged-particle (i.e., cosmic ray) fluxes that have been hypothesized to affect the formation of clouds. This could affect how much of the sun's energy is reflected back to space and how much is absorbed by our planet. Other possibilities are that some other core process could be having a more indirect effect on climate, or that an external (e.g. solar) process affects the core and climate simultaneously.

Regardless of the eventual connections to be established between the solid Earth and climate, Dickey said the solid Earth's impacts on climate are still dwarfed by the much larger effects of human-produced greenhouse gases. "The solid Earth plays a role, but the ultimate solution to addressing climate change remains in our hands," she concluded.

Study results were published recently in the Journal of Climate.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by NASA's Jet Propulsion Laboratory.

Chilly Times for Chinese Dinosaurs: Abundance of Feathered Dinosaurs During Temperate Climate With Harsh Winters

Dinosaurs did not always enjoy mild climates. New findings show that during part of the Early Cretaceous, north-east China had a temperate climate with harsh winters. They explain the abundance of feathered dinosaurs in fossil deposits of that period.
The discovery was made by an international collaboration coordinated by Romain Amiot of the Laboratoire de géologie de Lyon: terre, planètes et environnement (CNRS/ENS de Lyon/Université Lyon 1).

Their work is published in the Proceedings of the National Academy of Sciences.

It has long been thought that the climate of the Mesozoic, the age of the dinosaurs, was generally warm across the planet. However, a recent study challenges this theory. The work focuses on a region of north-east China where the Jehol fauna developed during part of the Early Cretaceous (between 125 and 110 million years ago). The fossils found in this deposit include many dinosaurs covered with filamentous structures similar to bird feathers (such structures can take on various forms, ranging from filaments, down and 'protofeathers' to true feathers). But is this feature due simply to excellent conditions of preservation or to the adaptation of such species to environmental conditions? Since these dinosaurs were unable to fly, several scientists have suggested that their feathers acted as thermal insulation.

A team of paleontologists from France, China, Japan and Thailand examined the issue and tried to determine the temperatures at that time. Teeth and bones from dinosaurs, mammalian reptiles, crocodiles, turtles and freshwater fish from fossil deposits containing the Jehol fauna were collected. This selection of samples was then completed by fossil remains from contemporary deposits in other regions of China, Japan and Thailand. The scientists analyzed the oxygen isotopic composition of each sample. They based their analysis on the principle that the average local air temperature determines the relative quantity of oxygen isotopes contained in the rainwater drunk by the animals. This isotope record is passed on and stored within the bones and teeth of animals as they grow. Since the oxygen contained in the mineralized tissue is preserved during fossilization, the researchers were able to reconstruct the prevailing air temperatures in the environment of Asian dinosaurs during the Early Cretaceous.

The results show that average temperatures in this period of the Early Cretaceous were very similar to those of today at equivalent latitudes (such as the climate in Beijing today). The Jehol fauna therefore lived in a cool temperate climate characterized by harsh winters during which cold-blooded reptiles (turtles and lizards) had to hibernate, whereas the down, feathers and fur of warm-blooded animals (mammals, birds and dinosaurs) enabled them to maintain sustained activity in winter. "These results do not prove in any way that feathers appeared because of their insulating characteristics. They show that feathers would have given the dinosaurs of the Jehol fauna a physiological advantage over their fellow animals with scales," points out Amiot, lead author of the paper and currently a CNRS researcher at the Laboratoire de géologie de Lyon (ENS de Lyon/Université de Lyon 1/CNRS).

This work helps us to better understand the Early Cretaceous period, of which there are few geological records, and sheds new light on existing theories about Earth at the time of the dinosaurs.

The laboratories involved are: Laboratoire de géologie de Lyon: terre, planètes et environnement (CNRS/Université Lyon 1/ENS de Lyon); Laboratoire de géologie de l'École normale supérieure (CNRS/ENS Paris); Institut de physique du globe de Paris (CNRS/UPMC/Université Paris Diderot); and the Institute of Vertebrate Paleontology and Paleoanthropology , Beijing, China.

Non-Native Snakes Are Taking a Toll on Native Birds, Scientists Find

The Everglades National Park in Florida is home to hundreds of species of native wildlife. It has also become the well-established home of the non-native Burmese python -- known to be a predator of native species. Now scientists, for the first time, have conducted a detailed analysis of the avian component of the python's diet and the negative impact the snakes may have on Florida's native birds, including some endangered species.
The Burmese python (Python molurus bivittatus), native to Southeast Asia, was first recorded in the Everglades in 1979 -- thought to be escaped or discarded pets. Their numbers have since grown, with an estimated breeding population in Florida in the tens of thousands. As researchers investigate the impact of this snake in the Everglades, scientists from the Smithsonian Institution, South Florida Natural Resources Center and the University of Florida examined the snake's predation of the area's birds. They found that birds, including endangered species, accounted for 25 percent of the python's diet in the Everglades.

"These invasive Burmese pythons are particularly hazardous to native bird populations in North America because the birds didn't evolve with this large reptile as a predator," said Carla Dove, ornithologist at the Smithsonian's Feather Identification Lab in the National Museum of Natural History. "Conversely, the python is able to thrive here partly because it has no natural predator to keep its numbers in check."

The scientists collected 343 Burmese pythons in Everglades National Park as part of their study between 2003 and 2008. Eighty-five of these snakes had bird remains in their intestinal tract. From these remains the team identified 25 species of birds by comparing feathers and bone fragments with specimens in the Smithsonian's collection. The results reflected a wide variety of species, from the 5-inch-long house wren to the 4-foot-long great blue heron. Four of the species identified (snowy egret, little blue heron, white ibis and limpkin) are listed as "species of special concern" by the Florida Fish and Wildlife Conservation Commission. The team also identified the remains of a wood stork, which is a federally endangered species.

"These pythons can also inhabit a wide variety of habitats, so their impact is not restricted to just the native species within the Everglades," Dove said. "The python's high reproductive rate, longevity, ability to consume large prey and consumption of bird species are causes for serious conservation and control measures."

The team's findings are published in the scientific journal BioOne, March 2011.

Egypt's Archaeological Sites Stand Unguarded

Concerned archaeologists called today on Egypt’s Prime Minister Essam Sharaf to return police to archaeological sites. The move is required to put an end to illegal excavations and wild looting of storehouses and tombs.

“The desecration of archaeological sites and monuments is not only a huge loss for the people of Egypt on a national, economic, and human level, but is also a loss to all of humanity and to science,” Tarek El Awadi, director of the National Egyptian museum, said in an open letter to Sharaf.

Following the revolution that toppled President Hosni Mubarak last month, a new unprecedented wave of looting and vandalism took place at various sites in Egypt.

“During the revolution of January 25th, the Egyptian Army protected our heritage sites and the Egyptian Museum in Cairo. However, in the last 10 days the army has left these posts because it has other tasks to do,” said Zahi Hawass, who resigned this week as minister of antiquities in protest at the lack of proper action on the looting.

“The group now in charge of the protection of these sites is the Tourist Police, but there are no Tourist Police to do this either,” Hawass said.

In the past few weeks, looters have removed inscribed blocks from tombs at Saqqara, Giza and Abusir, and even tried to cut into pieces a colossal red granite statue of the 19th Dynasty king Ramesses II at the southern quarry of Aswan.

One of the biggest losses is the tomb of the royal scribe Ken Amun in Tell el-Maskhuta, near Ismailia. Dating to the 19th Dynasty B.C (1315-1201 B.C.), the burial is the first ever Ramesside-period tomb uncovered in Lower Egypt.

Discovered last year, the burial featured beautifully decorated walls which are now a lost memory. Sadly, the site has been completely destroyed.

“Everyday, in the morning, I am waiting for news. What has been robbed today? What has been stolen today?” Hawass said. He will remain in his office until the government announce his successor.

Meanwhile, holding together on social networks, Egyptologists and archaeologists have started an international petition campaign to call for the restoration of adequate security to the sites, storehouses, monuments and antiquities of Egypt.

"The situation is certainly quite dire indeed," Andrew Bayuk, who started the petition, told Discovery News.

"This petition is an opportunity for the field of Egyptology to unite for a single purpose, and invite the support of other concerned people throughout the world to make a strong global statement," Bayuk, who created Guardian's Egypt, one of the oldest ancient Egypt website, said.

Photo: Statue of Ramesses II with visible cut marks on the front of the crown. Courtesy of SCA

'Very Cold' Brown Dwarf Discovered

A brown dwarf, about 75 light-years from Earth, has hit a new low. In fact, its temperature is so low that it is about the same temperature as the cup of tea sitting at my desk. Ladies and gentlemen, meet "CFBDSIR J1458+1013B," the sub-100 degree Celsius (212 F) failed star.*

A group of astronomers headed by Michael Liu, of the University of Hawaii, used the awesome power of adaptive optics on the 10-meter Keck II Telescope on Mauna Kea to probe the very faint infrared signature of this brown dwarf -- which exists as a brown dwarf binary, orbiting with its partner, CFBDSIR J1458+1013A -- revealing that the object may belong to a notoriously rare type of brown dwarf. This object is the faintest brown dwarf spotted by far and it is estimated to be only 6-15 times the mass of Jupiter.

You may have heard brown dwarfs being referred to as "failed stars" as they are not massive enough to support nuclear fusion in their cores, and yet they can't be called "planets" as they don't exhibit chemical differentiation with depth and have convective flows -- a very star-like quality. Therefore, they exist in a stellar hinterland, where they are neither a star or a planet, and yet exhibit characteristics of both.

But astronomers still classify brown dwarfs by their spectral type (a scale of letters assigned to the luminosity of stars), which relates to their temperature. At the lowest, coolest end of the scale, radiating in infrared wavelengths, are the oddball brown dwarfs.

So far, the coolest brown dwarfs observed exist at the lowest end of the scale, with a spectral class of "T." However, there is a theoretical class "Y" that is even cooler than the T-class brown dwarfs -- they are predicted to have a temperature less than 225 degrees Celsius (440 F).

More Like a Planet? More Like a Star?

Although Y-class candidates have been spotted by other instruments, the Keck telescope has put a very tight constraint on the temperature of CFBDSIR J1458+1013B and it looks as if this brown dwarf has more "planet-like" qualities than "star-like" qualities, with a temperature of 97 degrees Celsius (give or take 40 degrees C).

Could CFBDSIR J1458+1013B be the missing link between stars and planets? How can we work out if this object is more like Jupiter, say, or more like the sun?

Usually, water will exist in a gaseous state in brown dwarf atmospheres. But at such low temperatures, it is expected that water in the brown dwarf's atmosphere will condense to form clouds. Although it is hard to detect condensing water in this brown dwarf's atmosphere, it is certainly a prime "Y" class candidate.

Regardless, CFBDSIR J1458+1013B is the coolest brown dwarf in the cosmic neighborhood and it could help us understand the point at which a star becomes a star and a planet becomes a planet.

*Although brown dwarfs are known as "failed stars," I like to refer to them as "overachieving planets." Whoever said that becoming a star was the pinnacle of stellar living anyway?

Image credit: NASA, ESA and G. Bacon (STScI)

Huge Impact Crater Found in Remote Congo

A circular depression deep in the Democratic Republic of the Congo (DRC) has been confirmed as the first known impact crater in central Africa, a new study says. The find brings the number of known meteor craters on Earth to 182.

The so-called Luizi structure was first described in a German geological report from 1919. But without further fieldwork, it was impossible to say for sure that the 10.5-mile-wide (17-kilometer-wide) feature had been made by a meteor impact.

On other planets, such as Mercury and Mars, it's easier to identify impact craters based only on their shapes, since these worlds no longer have geologic forces making major changes to their surfaces.

But on Earth, many older craters have likely been erased by tectonic activity or erosion, while others are so covered with dense vegetation or sediments, like Luizi, that they're almost impossible to spot without satellites.

What's more, the crater-like structures we do see may have been made by volcanoes, collapsed underground chambers, and other forces that have nothing to do with impacts, said study leader Ludovic Ferrière, curator of the rock collection at the Natural History Museum of Vienna in Austria.

"On Earth, to confirm it's an impact, you have to go in the field because you need evidence of high pressures and temperatures," Ferrière said.

Crater Expedition Had Brushes With Snakes, Poachers

The researcher first became interested in the Luizi structure after seeing satellite pictures published in the 1990s.

By studying the available satellite data, Ferrière and colleagues estimated that the structure has an elevated rim about 1,148 feet (350 meters) high, as well as an interior ring and a central depression.

But to truly confirm Luizi as an impact crater, the researchers had to mount an expedition to the politically tumultuous DRC.

"I was working for a year just to find a contact there, because you need a local person to help you find your way around," Ferrière said.

With funding from the National Geographic Society/Waitt Foundation program, Ferrière—then a postdoc at the University of Western Ontario in Canada—visited the crater site in June 2010 with colleagues from the University of Lubumbashi.

"I flew direct to Lubumbashi, the second largest city in the DRC. From there we had to drive from the city to the crater," he said.

"I had looked at maps and planned a route before I left. But when I got there, my contact told me there is no bridge across part of my intended path. We had to take some crazy gravel roads with big potholes inside. These are not good roads to drive on, even with a four-wheel-drive car."

The team set up camp in a small village about 8 miles (13 kilometers) from the crater rim, recruiting two local guides/porters and a soldier to help them safely navigate the wild terrain.

"The crater is in a national park, and I thought it would be like the jungles of South America," Ferrière said. "Instead it was a tree savanna—a big plataeu with dry grass. The grass was sometimes more than a meter [3.2 feet] high."

Standing on the rim of the Luizi structure, Ferrière could see skinny trees that seemed to fill the depression, with the crater's distant edge rising like small hills.

Despite the remote, wooded terrain, "we saw no large animals, only snakes. But we did see a lot of remnants of poachers. Sometimes we'd come to a site and the doused fires were still hot."

Congo Rocks Had a Shock

Ferrière's team spent about a week at the crater collecting samples, which were sent back to the lab in Canada for analysis.

"I found so-called shatter cones, which are features in the rock only found in impact structures," he said. The nested, conical shapes in such features are evidence that the bedrock has been exposed to extreme pressure from a shock wave.

The crater rocks also contained an abundance of shocked quartz, a version of the mineral known to form only from impacts or nuclear blasts, Ferrière said.

"Everybody will believe me now, I think, that this is an impact site."

The scientists think the Luizi crater was made by a meteor more than 0.6 mile (a kilometer) wide that slammed into what is now the DRC at about 45,000 miles (72,000 kilometers) an hour.

For now it's unclear how old the crater is—the scientists can say only that the affected rocks are about 575 million years old, "but we know it's younger than that, because the rocks have been excavated," Ferrière said.

"It would be nice to do more fieldwork, because the shape of the structure with this inner ring can tell us about the exact formation process involved," he added. In the meantime, the researcher will continue to study the rock samples, now housed at the Vienna museum.

"There is still a lot to discover" about Luizi, he said.

Experts Push NASA to Focus on Search for Life

The search for life in the solar system, whether in rocks from Mars or on a Jovian moon, tops the wish list of a panel of space scientists convened by the National Research Council. Mindful of shrinking budgets, the panel has issued hard-nosed recommendations that identify which planetary science missions NASA should fly in the decade beginning 2013. Even some top-rated missions should be either deferred or outright canceled if their estimated costs can’t be significantly cut, the panel says in a report released March 7.

Among its big missions, the panel says, NASA should give highest priority to the Mars Astrobiology Explorer-Cacher. This project would be the first of three missions designed to collect Martian samples and bring them to Earth for analysis of any evidence of life forms. But the panel of space scientists recommends that the mission should go forward only if NASA’s cost can be limited to $2.5 billion; $1 billion less than the project’s estimated price tag in fiscal year 2015 dollars (adjusted for inflation). The European Space Agency and NASA, which will jointly run the mission, should work together to reduce the high cost, the report suggests. One possibility is to include one large robot instead of two.

“I’m ready to hit the ground running with Europe to see if we can do something with that first priority,” says Ed Weiler, NASA’s associate administrator for science in Washington, D.C.

NASA’s Jupiter Europa Orbiter also received a nod from the panel, which ranked the mission as the second-highest priority among large projects. The craft would carry a suite of instruments to determine if Jupiter’s moon Europa has an ocean — a possible haven for life — buried beneath its icy surface, as many scientists suspect. But the panel says the mission should fly only if the project’s current estimated cost of $4.7 billion is reduced and if NASA increases its planetary science budget. The panel did not say specifically how much to cut from the Europa mission in order to maintain funding of other projects, but did spell out a 5 percent boost to NASA’s planetary science research funding compared with fiscal year 2011. The panel also recommends that the planetary science budget should remain 1.5 percent above inflation for the remainder of the decade.

Exploring the structure, composition and atmosphere of Uranus with an orbiter and probe also earned a high mark from the panel, which rated the project third among NASA’s large missions. But the panel recommends the mission be reduced in scope or canceled if it rises above its estimated $2.7 billion cost.