NASA’s Van Allen Probes reveal a new radiation belt around Earth

Two giant swaths of radiation, known as the Van Allen Belts, surrounding Earth were discovered in 1958. In 2012, observations from the Van Allen Probes showed that a third belt can sometimes appear. The radiation is shown here in yellow, with green representing the spaces between the belts. (Credit: NASA/Van Allen Probes/Goddard Space Flight Center)

Feb. 28, 2013 — NASA’s Van Allen Probes mission has discovered a previously unknown third radiation belt around Earth, revealing the existence of unexpected structures and processes within these hazardous regions of space.

Previous observations of Earth’s Van Allen belts have long documented two distinct regions of trapped radiation surrounding our planet. Particle detection instruments aboard the twin Van Allen Probes, launched Aug. 30, quickly revealed to scientists the existence of this new, transient, third radiation belt.

The belts, named for their discoverer, James Van Allen, are critical regions for modern society, which is dependent on many space-based technologies. The Van Allen belts are affected by solar storms and space weather and can swell dramatically. When this occurs, they can pose dangers to communications and GPS satellites, as well as humans in space.

“The fantastic new capabilities and advances in technology in the Van Allen Probes have allowed scientists to see in unprecedented detail how the radiation belts are populated with charged particles and will provide insight on what causes them to change, and how these processes affect the upper reaches of Earth’s atmosphere,” said John Grunsfeld, NASA’s associate administrator for science in Washington.

This discovery shows the dynamic and variable nature of the radiation belts and improves our understanding of how they respond to solar activity. The findings, published February 28 in the journal Science, are the result of data gathered by the first dual-spacecraft mission to fly through our planet’s radiation belts.

The new high-resolution observations by the Relativistic Electron Proton Telescope (REPT) instrument, part of the Energetic Particle, Composition, and Thermal Plasma Suite (ECT) aboard the Van Allen Probes, revealed there can be three distinct, long-lasting belt structures with the emergence of a second empty slot region, or space, in between.

“This is the first time we have had such high-resolution instruments look at time, space and energy together in the outer belt,” said Daniel Baker, lead author of the study and REPT instrument lead at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado in Boulder. “Previous observations of the outer radiation belt only resolved it as a single blurry element. When we turned REPT on just two days after launch, a powerful electron acceleration event was already in progress, and we clearly saw the new belt and new slot between it and the outer belt.”

Scientists observed the third belt for four weeks before a powerful interplanetary shock wave from the sun annihilated it. Observations were made by scientists from institutions including LASP; NASA’s Goddard Space Flight Center in Greenbelt, Md.; Los Alamos National Laboratory in Los Alamos, N.M.; and the Institute for the Study of Earth, Oceans, and Space at the University of New Hampshire in Durham.

Each Van Allen Probe carries an identical set of five instrument suites that allow scientists to gather data on the belts in unprecedented detail. The data are important for the study of the effect of space weather on Earth, as well as fundamental physical processes observed around other objects, such as planets in our solar system and distant nebulae.

“Even 55 years after their discovery, the Earth’s radiation belts still are capable of surprising us and still have mysteries to discover and explain,” said Nicky Fox, Van Allen Probes deputy project scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. “We thought we knew the radiation belts, but we don’t. The advances in technology and detection made by NASA in this mission already have had an almost immediate impact on basic science.”

The Van Allen Probes are the second mission in NASA’s Living With a Star Program to explore aspects of the connected sun-Earth system that directly affect life and society. Goddard manages the program. The Applied Physics Laboratory built the spacecraft and manages the mission for NASA.

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Independent, skeptic-funded study confirms Global Warming is real

The Berkeley Earth Surface Temperature study has just released a summary of a recently completed global land warming analysis showing “reliable evidence of a rise in average world land temperature by approximately one degree Celsius since the mid-1950s.” Yeah, we’ve heard that before, but this is one study that even skeptics may have to believe.

Here’s why the Berkeley Earth Project is different from all previous studies on global warming:

  • It’s independent. No government sponsored or directed the Berkeley Earth Project, so none of the researchers involved had to deal with the same kind of political pressure as previous studies.
  • It’s non-profit, supported by donations. The private sector is almost entirely responsible for funding the Berkeley Earth Project, and the largest single donation ($150,000) came from the Charles G. Koch Charitable Foundation, noted multi-million dollar supporter of climate change skepticism.
  • It’s open source. Got a problem with the results? The entire data set along with the programs used to analyze said data set are all online, ready for anyone to explore.
  • It uses more data than any other study. The Berkeley Earth Project’s temperature database consists of records from 39,000 temperature stations around the world, amounting to 1.6 billion individual measurements. This is about five times the amount of data used in most previous climate change studies.
  • It directly addresses the concerns that skeptics raised about previous studies. This includes the potential effect of urban heat islands, the quality of temperature monitoring stations, and selection bias risk.

Let’s just assume, for a moment, that the Berkeley Earth Surface Temperature study is legit. What exactly did they find? Well, in a nutshell, global warming is definitely real. Since the mid-1950s, average global land temperatures have risen by nearly two degrees Fahrenheit. For what it’s worth, this agrees very closely with previous global warming studies that were dismissed by skeptics for one reason or another. The Berkeley study also found that pretty much everything that climate change skeptics used to discredit previous studies ultimately made no statistically significant differences to the overall result.

So at this point, what’s obviously going to happen is that global warming skeptics and deniers will get together and say, “okay, you’ve convinced us, we’re sorry for all that merciless slandering and we should get together and talk about what climate change means for the future of our planet.” Right?

Yeah, probably not. What’s probably going to happen is that deniers will continue to deny the science without much of a foundation just because they can, or they’ll shift the topic from whether global warming exists to whether humans are causing it. What it really comes down to, though, is that the Earth’s climate is changing, and those changes are starting to have a direct impact on our lives. That impact is only going to increase, and whatever the cause is, if there are things we can do to help keep this planet stable, it just seems like a no-brainer to try our best to make that happen.

Berkeley Earth, via Discover

Independent, skeptic-funded study confirms Global Warming is real

China''''s Rare-Earth Monopoly

An attractive material: Neodymium (shown here) is one of the rare-earth elements that are key to making very strong magnets for compact electric motors.  Credit: Hi-Res Images of Chemical Elements

The rest of the world is trying to find alternatives to these crucial materials.

By Adam Aston

For three weeks, China has blocked shipments of rare-earth minerals to Japan, a move that has boosted the urgency of efforts to break Beijing””s control of these minerals. China now produces nearly all of the world””s supply of rare earths, which are crucial for a wide range of technologies, including hard drives, solar panels, and motors for hybrid vehicles.

In response to China””s dominance in rare-earths production, researchers are developing new materials that could either replace rare-earth minerals or decrease the need for them. But materials and technologies will likely take years to develop, and existing alternatives come with trade-offs.

China apparently blocked the Japan shipments in response to a territorial squabble in the South China Sea. Beijing has denied the embargo, yet the lack of supply may soon disrupt manufacturing in Japan, trade and industry minister Akihiro Ohata told reporters Tuesday.

Rare earths are comprised of 17 elements, such as terbium, which is used to make green phosphors for flat-panel TVs, lasers, and high-efficiency fluorescent lamps. Neodymium is key to the permanent magnets used to make high-efficiency electric motors. Although well over 90 percent of the minerals are produced in China, they are found in many places around the world, and, in spite of their name, are actually abundant in the earth””s crust (the name is a hold-over from a 19th-century convention). In recent years, low-cost Chinese production and environmental concerns have caused suppliers outside of China to shut down operations.

Alternatives to rare earths exist for some technologies. One example is the induction motor used by Palo Alto, California-based Tesla Motors in its all-electric Roadster. It uses electromagnets rather than permanent rare-earth magnets. But such motors are larger and heavier than ones that use rare-earth magnets. As a rule of thumb, in small- and mid-sized motors, an electromagnetic coil can be replaced with a rare-earth permanent magnet of just 10 percent the size, which has helped make permanent magnet motors the preferred option for Toyota and other hybrid vehicle makers. In Tesla””s case, the induction motor technology was worth the trade-off, giving the car higher maximum power in more conditions, a top priority for a vehicle that can rocket from zero to 60 mph in 3.7 seconds. “The cost volatility going into the rare-earth permanent magnets was a concern,” says JB Straubel, Tesla””s chief technology officer. “We couldn””t have predicted the geopolitical tensions.”

More manufacturers are following Tesla””s lead to shun the rare-earth materials, although the move means sacrificing space and adding weight to vehicles. A week after the China dust-up began, a research team in Japan announced they had made a hybrid vehicle motor free of rare-earth materials, and Hitachi has announced similar efforts. BMW””s Mini E electric vehicle uses induction motors, and Tesla is supplying its drive trains to Toyota””s upcoming electric RAV 4. Given the volatility of rare-earth supplies, and the advantages induction motors offer in high performance applications, “It makes sense for car companies to give serious thought to using induction motors,” says Wally Rippel, senior scientist at AC Propulsion. Rippel previously worked on induction motor designs at Tesla and GM, where he helped to develop the seminal EV1.

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Carbon Dioxide Controls Earth''s Temperature, New Modeling Study Shows

Various atmospheric components differ in their contributions to the greenhouse effect, some through feedbacks and some through forcings. Without carbon dioxide and other non-condensing greenhouse gases, water vapor and clouds would be unable to provide the feedback mechanisms that amplify the greenhouse effect. (Credit: NASA GISS)

Water vapor and clouds are the major contributors to Earth”s greenhouse effect, but a new atmosphere-ocean climate modeling study shows that the planet”s temperature ultimately depends on the atmospheric level of carbon dioxide.

The study, conducted by Andrew Lacis and colleagues at NASA”s Goddard Institute for Space Studies (GISS) in New York, examined the nature of Earth”s greenhouse effect and clarified the role that greenhouse gases and clouds play in absorbing outgoing infrared radiation. Notably, the team identified non-condensing greenhouse gases — such as carbon dioxide, methane, nitrous oxide, ozone, and chlorofluorocarbons — as providing the core support for the terrestrial greenhouse effect.

Without non-condensing greenhouse gases, water vapor and clouds would be unable to provide the feedback mechanisms that amplify the greenhouse effect. The study”s results are published Oct. 15 in Science.

A companion study led by GISS co-author Gavin Schmidt that has been accepted for publication in the Journal of Geophysical Research shows that carbon dioxide accounts for about 20 percent of the greenhouse effect, water vapor and clouds together account for 75 percent, and minor gases and aerosols make up the remaining five percent. However, it is the 25 percent non-condensing greenhouse gas component, which includes carbon dioxide, that is the key factor in sustaining Earth”s greenhouse effect. By this accounting, carbon dioxide is responsible for 80 percent of the radiative forcing that sustains the Earth”s greenhouse effect.

The climate forcing experiment described in Science was simple in design and concept — all of the non-condensing greenhouse gases and aerosols were zeroed out, and the global climate model was run forward in time to see what would happen to the greenhouse effect.

Without the sustaining support by the non-condensing greenhouse gases, Earth”s greenhouse effect collapsed as water vapor quickly precipitated from the atmosphere, plunging the model Earth into an icebound state — a clear demonstration that water vapor, although contributing 50 percent of the total greenhouse warming, acts as a feedback process, and as such, cannot by itself uphold the Earth”s greenhouse effect.

“Our climate modeling simulation should be viewed as an experiment in atmospheric physics, illustrating a cause and effect problem which allowed us to gain a better understanding of the working mechanics of Earth”s greenhouse effect, and enabled us to demonstrate the direct relationship that exists between rising atmospheric carbon dioxide and rising global temperature,” Lacis said.

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Rare Melt Key to ‘Ring of Fire’

Scientists investigated why the world”s explosive volcanoes are confined to bands only a few tens of kilometres wide. (Credit: iStockphoto/James Steidl)

Oxford University scientists have discovered the explanation for why the world”s explosive volcanoes are confined to bands only a few tens of kilometres wide, such as those along the Pacific ”Ring of Fire”. Most of the molten rock that comes out of these volcanoes is rich in water, but the Oxford team has shown that the volcanoes are aligned above narrow regions in the mantle where water-free melting can take place. They publish a report of their research in the journal Nature.

These volcanic chains have been responsible for the most devastating eruptions in history, such as that of Krakatoa in 1883, and the huge eruption of Toba about 74,000 years ago, whose aftermath may have come close to extinguishing the human race.

”It has been recognised for almost 50 years that the volcanic arcs form where one oceanic plate sinks beneath another,” said Professor Philip England of Oxford University”s Department of Earth Sciences, an author of the report, ”but while many models of this process have been put forward, none has been able to explain the location, and narrowness, of the volcanic arcs.”

The eruptions of volcanoes in the Ring of Fire are extremely violent (in contrast with the relatively gentle eruption in Iceland that paralysed European air travel in April) because the molten rock contains a high proportion of water which, as superheated gas, provides the power for the explosive eruptions. This water is liberated from the plates descending beneath the volcanoes and lowers the melting point of rocks in the mantle.

”Most previous explanations for the origins of volcanoes suggested that this kind of ”wet” melting is responsible for getting a volcano started,” said Dr Richard Katz of Oxford University”s Department of Earth Sciences, an author of the report. The difficulty with such explanations is that wet melting occurs over very broad regions of the mantle, inconsistent with the narrowness of the volcanic chains. ”However, we noticed that there is a very simple geometrical pattern in the distribution of the volcanoes which provides a powerful clue as to what is going on,” added Dr Katz.

Using a mathematical model of heat transport in the regions where two plates collide, the Oxford team showed that the observed geometrical pattern can only be explained if the volcanoes are localized above the narrow regions in which mantle melts in the absence of water. Melt rising from this region blazes a trail for more water-rich magma to follow all the way to the surface where it erupts to form volcanoes.

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Plants Kick-Started Evolutionary Drama of Earth''''s Oxygenation

A panser shark (predatory fish greater than 30 feet long) is a consequence of the Earth””s oxygenation event of 400 million years ago. (Credit: Staffan Waerndt / Swedish Museum of Natural History)

An international team of scientists, exploiting pioneering techniques at Arizona State University, has taken a significant step toward unlocking the secrets of oxygenation of the Earth””s oceans and atmosphere.

Evolution of the Earth””s multitude of organisms is intimately linked to the rise of oxygen in the oceans and atmosphere. The new research indicates that the appearance of large predatory fish as well as vascular plants approximately 400 million years ago coincided with an increase in oxygen, to levels comparable to those we experience today. If so, then animals from before that time appeared and evolved under markedly lower oxygen conditions than previously thought.

The researchers, including collaborators from Harvard, Denmark, Sweden and the United Kingdom, made use of a method developed at ASU by Ariel Anbar, a professor in the department of chemistry and biochemistry and the School of Earth and Space Exploration in the College of Liberal Arts and Sciences, and his research group. The method can be used to estimate global oxygen levels in ancient oceans from the chemical composition of ancient seafloor sediments.

Their important findings are presented in a paper published in the Proceedings of the National Academy of Sciences (PNAS), titled “Devonian rise in atmospheric oxygen correlated to radiations of terrestrial plants and large predatory fish.”

“There has been a lot of speculation over the years about whether or not oxygen in the atmosphere was steady or variable over the last 500 million years,” explained Anbar, who leads ASU””s Astrobiology Program. “This is the era during which animals and land plants emerged and flourished. So it””s a profound question in understanding the history of life. These new findings not only suggest that oxygen levels varied, but also that the variation had direct consequences for the evolution of complex life.”

The Earth is 4,500 million years old. Microbial life has probably thrived in the oceans for most of that time. However, until about 2,300 million years ago, the atmosphere contained only traces of oxygen. During that time, some microbes in the oceans likely produced oxygen as a byproduct of photosynthesis. But the quantities they produced were insufficient to accumulate much in the atmosphere and oceans. The situation changed with the “Great Oxidation Event,” 2,300 million years ago. Oxygen levels rose again around 550 million years ago. The first animals appear in the fossil record at this time, marking the beginning of an era that geologists call the “Phanerozoic” — a Greek word meaning “evident animals.” This new work explores how oxygen levels changed during the Phanerozoic.

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Population Change: Another Big Influence on Climate Change

Changes in population, including aging and urbanization, could significantly affect global emissions of carbon dioxide over the next 40 years, according to a new study. (Credit: iStockphoto)

Changes in population, including aging and urbanization, could significantly affect global emissions of carbon dioxide over the next 40 years, according to a new study.

The study, published in the Proceedings of the National Academy of Sciences (PNAS), was conducted by researchers from the National Center for Atmospheric Research (NCAR), the International Institute for Applied Systems Analysis (IIASA), and the National Oceanographic and Atmospheric Administration. It was funded by a European Young Investigator””s Award*, the Hewlett Foundation, and the US National Science Foundation.

By mid-century it is estimated that global population could rise by more than three billion people, with most of that increase occurring in urban areas. The study showed that a slowing of that population growth could contribute to significantly reducing greenhouse gas emissions. By 2050, the researchers found that if population followed one of the slower growth paths foreseen as plausible by demographers at the United Nations, it could provide 16 to 29 percent of the emission reductions thought necessary to keep global temperatures from causing serious impacts. The effect of slower population growth on greenhouse gas emissions would be even larger by the end of the century.

“If global population growth slows down, it is not going to solve the climate problem, but it can make a contribution, especially in the long term,” says the study””s lead author and NCAR scientist Brian O””Neill.

Study co-author and IIASA scientist Shonali Pachauri says that slower population growth will have different influences, depending on where it occurs. “A slowing of population growth in developing countries today will have a large impact on future global population size. However, slower population growth in developed countries will matter to emissions too because of higher per capita energy use,” says Dr Pachauri.

Scientists have long known that changes in population will have some effect on greenhouse gas emissions, but there has been debate on how large that effect might be.

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