Astronomers solve mystery of vanishing electrons in Earth's outer radiation belt

ScienceDaily (Jan. 29, 2012) ? UCLA researchers have explained the puzzling disappearing act of energetic electrons in Earth's outer radiation belt, using data collected from a fleet of orbiting spacecraft.

In a paper published Jan. 29 in the advance online edition of the journal Nature Physics, the team shows that the missing electrons are swept away from the planet by a tide of solar wind particles during periods of heightened solar activity.

"This is an important milestone in understanding Earth's space environment," said lead study author Drew Turner, an assistant researcher in the UCLA Department of Earth and Space Sciences and a member of UCLA's Institute for Geophysics and Planetary Physics (IGPP). "We are one step closer towards understanding and predicting space weather phenomena."

During powerful solar events such as coronal mass ejections, parts of the magnetized outer layers of sun's atmosphere crash onto Earth's magnetic field, triggering geomagnetic storms capable of damaging the electronics of orbiting spacecraft. These cosmic squalls have a peculiar effect on Earth's outer radiation belt, a doughnut-shaped region of space filled with electrons so energetic that they move at nearly the speed of light.

"During the onset of a geomagnetic storm, nearly all the electrons trapped within the radiation belt vanish, only to come back with a vengeance a few hours later," said Vassilis Angelopoulos, a UCLA professor of Earth and space sciences and IGPP researcher.

The missing electrons surprised scientists when the trend was first measured in the 1960s by instruments onboard the earliest spacecraft sent into orbit, said study co-author Yuri Shprits, a research geophysicist with the IGPP and the departments of Earth and space sciences, and atmospheric and oceanic sciences.

"It's a puzzling effect," he said. "Oceans on Earth do not suddenly lose most of their water, yet radiation belts filled with electrons can be rapidly depopulated."

Even stranger, the electrons go missing during the peak of a geomagnetic storm, a time when one might expect the radiation belt to be filled with energetic particles because of the extreme bombardment by the solar wind.

Where do the electrons go? This question has remained unresolved since the early 1960s. Some believed the electrons were lost to Earth's atmosphere, while others hypothesized that the electrons were not permanently lost at all but merely temporarily drained of energy so that they appeared absent.

"Our study in 2006 suggested that electrons may be, in fact, lost to the interplanetary medium and decelerated by moving outwards," Shprits said. "However, until recently, there was no definitive proof for this theory."

To resolve the mystery, Turner and his team used data from three networks of orbiting spacecraft positioned at different distances from Earth to catch the escaping electrons in the act. The data show that while a small amount of the missing energetic electrons did fall into the atmosphere, the vast majority were pushed away from the planet, stripped away from the radiation belt by the onslaught of solar wind particles during the heightened solar activity that generated the magnetic storm itself.

A greater understanding of Earth's radiation belts is vital for protecting the satellites we rely on for global positioning, communications and weather monitoring, Turner said. Earth's outer radiation belt is a harsh radiation environment for spacecraft and astronauts; the high-energy electrons can penetrate a spacecraft's shielding and wreak havoc on its delicate electronics. Geomagnetic storms triggered when the oncoming particles smash into Earth's magnetosphere can cause partial or total spacecraft failure.

"While most satellites are designed with some level of radiation protection in mind, spacecraft engineers must rely on approximations and statistics because they lack the data needed to model and predict the behavior of high-energy electrons in the outer radiation belt," Turner said.

During the 2003 "Halloween Storm," more than 30 satellites reported malfunctions, and one was a total loss, said Angelopoulos, a co-author of the current research. As the solar maximum approaches in 2013, marking the sun's peak activity over a roughly 11-year cycle, geomagnetic storms may occur as often as several times per month.

"High-energy electrons can cut down the lifetime of a spacecraft significantly," Turner said. "Satellites that spend a prolonged period within the active radiation belt might stop functioning years early."

While a mechanized spacecraft might include multiple redundant circuits to reduce the risk of total failure during a solar event, human explorers in orbit do not have the same luxury. High-energy electrons can punch through astronauts' spacesuits and pose serious health risks, Turner said.

"As a society, we've become incredibly dependent on space-based technology," he said. "Understanding this population of energetic electrons and their extreme variations will help create more accurate models to predict the effect of geomagnetic storms on the radiation belts."

Key observational data used in this study was collected by a network of NASA spacecraft known as THEMIS (Time History of Events and Macroscale Interactions during Substorms); Angelopoulos is the principal investigator of the THEMIS mission. Additional information was obtained from two groups of weather satellites called POES (Polar Operational Environmental Satellite) and GOES (Geostationary Operational Environmental Satellite).

A new collaboration between UCLA and Russia's Moscow State University promises to paint an even clearer picture of these vanishing electrons. Slated for launch in the spring of 2012, the Lomonosov spacecraft will fly in low Earth orbit to measure highly energetic particles with unprecedented accuracy, said Shprits, the principal investigator of the project. Several key instruments for the mission are being developed and assembled at UCLA.

Earth's radiation belts were discovered in 1958 by Explorer I, the first U.S. satellite that traveled to space.

"What we are studying was the first discovery of the space age," Shprits said. "People realized that launches of spacecraft didn't only make the news, they could also make scientific discoveries that were completely unexpected."

This project received federal funding from NASA and the National Science Foundation. Other co-authors include Michael Hartinger, a UCLA graduate student in Earth and space sciences.

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Story Source:

The above story is reprinted from materials provided by University of California - Los Angeles. The original article was written by Kim DeRose.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Drew L. Turner, Yuri Shprits, Michael Hartinger, Vassilis Angelopoulos. Explaining sudden losses of outer radiation belt electrons during geomagnetic storms. Nature Physics, 2012; DOI: 10.1038/nphys2185

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Source: http://www.sciencedaily.com/releases/2012/01/120129150958.htm

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HBT: Oswalt reportedly to sign with Cardinals

UPDATE: Hold your horses, everyone. When most of us went to bed, it appeared as though Roy Oswalt was St. Louis-bound. That may still be the case, but Gordon Edes of ESPNBoston.com has backtracked a bit from his previous report. He calls a deal likely to happen ?soon? and was told by a source that it?s ?not 100 percent? yet.

Meanwhile, Joe Strauss of the St. Louis Post-Dispatch reports?that the Cardinals are insisting that no deal is in place with Oswalt.?Any deal would be contingent upon a physical and the veteran right-hander has a history of back problems, so it?s possible some formalities are standing in the way of an official agreement.

1:09 AM: Gordon Edes of ESPNBoston.com reports that Roy Oswalt is headed to the Cardinals. No word yet on the terms of the contract.

8:36 PM, Friday: Jim Duquette of MLB Network Radio on Sirius XM reports that the Cardinals and Roy Oswalt are close to agreeing on a contract. Michael Silverman of the Boston Herald?confirms Duquette?s report, but adds that the process may take ?another day or two.?

No word on the specific terms being discussed, but Joe Strauss of the St. Louis Post-Dispatch reported earlier this week that the Cardinals made an offer to Oswalt a few weeks ago ?approaching $5 million.? Strauss didn?t think that would be enough to get it done and even pegged the Rangers as the favorites.

As for Duquette, he hears that the Red Sox, Astros and Rangers remain in the mix. The Astros are a bit of a head-scratcher given that they haven?t been mentioned until this point and aren?t anywhere close to contending, but perhaps Oswalt gave some thought to going back to where it all started.

Of course, the interesting part of a potential match with the Cardinals is that they already have five starters and Kyle Lohse and Jake Westbrook have full no-trade clauses in their respective contracts. By the way, Lohse will make $11.57 million in 2012 while Westbrook is owed $8.5 million this season and a $1 million buyout on his $8.5 million mutual option for 2013. Oswalt has the potential to make them better, obviously, but that could be a messy situation.

Source: http://hardballtalk.nbcsports.com/2012/01/28/report-cardinals-and-roy-oswalt-close-to-agreement/related/

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Private investors near deal on Greek debt (AP)

ATHENS, Greece ? A disorderly and potentially devastating Greek debt default is looking much less likely.

Greece and investors who own its bonds have reached a tentative deal to significantly reduce the country's debt and pave the way for it to receive a much-needed euro130 billion bailout.

Negotiators for the investors announced the agreement Saturday and said it could become final next week. If the agreement works as planned, it will help Greece remain solvent and help Europe avoid a blow to its already weak financial system, even though banks and other bond investors will have to accept multibillion-dollar losses.

Still, it doesn't resolve the weakening economic conditions in Greece and other European nations as they rein in spending to get their debts under control.

Under the agreement, investors holding euro206 billion in Greek bonds would exchange them for new bonds worth 60 percent less.

The new bonds' face value is half of the existing bonds. They would have a longer maturity and pay an average interest rate of slightly less than 4 percent. The existing bonds pay an average interest rate of 5 percent, according to the think tank Re-Define.

The deal would reduce Greece's annual interest expense on the bonds from about euro10 billion to about euro4 billion. And when the bonds mature, instead of paying bondholders euro206 billion, Greece will have to pay only euro103 billion.

Without the deal, which would reduce Greece's debt load by at least euro120 billion, the bonds held by banks, insurance companies and hedge funds would likely become worthless. Many of these investors also hold debt from other countries that use the euro, which could also lose value in the event of a full-fledged Greek default. This is the scenario analysts fear most and why they hope investors will voluntarily accept a partial loss on their Greek bonds.

The agreement taking shape is a key step before Greece can get a second, euro130 billion bailout from its European Union partners and the International Monetary Fund. Besides restructuring its debt with private investors, Greece must also take other steps before getting aid. It must cut its deficit and boost the competitiveness of its economy through layoffs of government employees and the sale of several state companies, among other moves.

Greece faces a euro14.5 billion bond repayment on March 20, which it cannot afford without additional help.

The country got its first bailout in May 2010 when the EU and the IMF signed off on a euro110 billion aid package, most of which has already been disbursed.

Private investors hold roughly two-thirds of Greece's debt, which has reached an unsustainable level ? nearly 160 percent of the country's annual economic output. By restructuring the debt held by private investors, Greece and its EU partners are hoping to bring that ratio closer to 120 percent by the end of this decade. Without a deal, analysts forecast that ratio ballooning to 200 percent by the end of this year as the Greek economy falters.

Meanwhile, Greece's public creditors ? the IMF, the EU and the European Central Bank ? are baffled by the government's repeated failure to meet deficit targets. They want more government wage cuts. That is meeting resistance by Greek politicians afraid of losing an election tentatively scheduled for the spring. But those same politicians also worry that the nation will be denied a second bailout if doesn't reduce its deficit.

Greek Finance Minister Evangelos Venizelos on Saturday night asked those who oppose structural changes to reconsider their stance.

"The coming days will be decisive for the next decade ... We must answer to tough dilemmas and we must do so with foresight and a sense of responsibility and not hide behind each other," he told reporters after meeting with the public creditors.

In return for the first bailout, Greece's public creditors have unprecedented powers over Greek spending. However, Greece's problems will not be fixed simply by cutting government spending. In order to bring its debts to a more manageable level, the country must also find ways boost economic output, which would enable it to collect more taxes.

If no debt-exchange deal is reached with private creditors and Greece is forced to default, it would very likely spook Europe's ? and possibly the world's ? financial markets. It could even lead Greece to withdraw from the euro.

Sarah Ketterer, co-manager of Causeway International Value Fund, a $1.4 billion mutual fund that invests in European stocks, said the region's markets have rebounded this month largely on expectations that negotiators would reach a deal along the lines of the one being finalized now.

Any last-minute breakdown in the talks could trigger a sharp decline in European markets, she said. But a rally is unlikely if negotiations succeed.

"The equity markets have ... largely already discounted this, and you can see that in the confidence that has returned in European equities since the end of December, and especially for financial stocks," Ketterer said.

She said there "really was no other option" than reaching a deal for bondholders to take a haircut of 50 percent or more.

Ketterer said a Greek deal could help restore bond market confidence. That would help Italy manage its own debt crisis ? one that Ketterer views as more critical than Greece's because of Italy's greater size.

The investors who own Greek bonds are being represented by Charles Dallara, managing director of the Washington-based Institute of International Finance, and Jean Lemierre, senior adviser to the chairman of the French bank BNP Paribas.

___

AP personal finance writer Mark Jewell in Boston, Elena Becatoros in Athens and Gabriele Steinhauser in Brussels contributed to this report.

Source: http://us.rd.yahoo.com/dailynews/rss/business/*http%3A//news.yahoo.com/s/ap/20120129/ap_on_bi_ge/eu_greece_financial_crisis

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How states fared on unemployment aid, at a glance (AP)

More people sought unemployment benefits last week, though the increase comes one week after applications fell to their lowest level in four years. Layoffs have fallen in recent months and fewer people are seeking benefits, signs of a healthier job market.

States with the biggest decreases:

New York: Down 27,713, due to fewer layoffs in the transportation, education and construction industries

Pennsylvania: Down 11,687, no reason given

North Carolina: Down 9,516 due to fewer layoffs in the textile, furniture and fixtures, services, construction and manufacturing industries

Georgia: Down 9,496, due to fewer layoffs in the service, construction, trade and manufacturing industries

Alabama: Down 7,639, due to fewer layoffs in the transportation, construction and apparel industries

Texas: Down 6,880, no reason given

States with the largest increases:

Florida: Up 2,711, due to layoffs in services, agriculture, construction and retail

California: Up 1,682, due to layoffs in services

Source: http://us.rd.yahoo.com/dailynews/rss/economy/*http%3A//news.yahoo.com/s/ap/20120126/ap_on_bi_ge/us_unemployment_benefits_glance

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Video: Can Gingrich take the GOP down?

Surprising 30 percent rise in home births

A small, but growing trend of women in the US are choosing home births, a new government report finds. These mostly over 35, non-Hispanic white women are "consciously rejecting the system" of hospital deliveries, says the researcher.

Source: http://www.msnbc.msn.com/id/3036697/vp/46154554#46154554

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Car bomb targeting NATO aid team kills 4 Afghans (AP)

KABUL, Afghanistan ? A suicide car bomber targeting a NATO-sponsored reconstruction team killed four Afghan civilians, including a child, and wounded 31 on Thursday in southern Afghanistan, officials said.

Three civilian international members of the aid team ? two men and one woman ? were among the wounded, said Daud Ahmadi, a spokesman for the provincial governor. He said their injuries were not life threatening and did not know their nationalities.

The bomber detonated his explosives-laden vehicle Thursday morning as a convoy of a NATO Provincial Reconstruction Team passed by in Lashkar Gah, capital of Helmand province, Ahmadi said.

The blast ripped through the convoy of armored vehicles, knocking at least one over and charring others. The explosion also shredded nearby storefronts and damaged at least 17 civilian cars nearby, a provincial statement said.

Provincial Reconstruction Teams are joint international military-civilian units dedicated to aid projects to boost support for the Afghan government of President Hamid Karzai. They are sponsored by the NATO military coalition and there are 27 now operating in Afghanistan.

Afghan National Army soldier Dad Mohammad witnessed the attack while on patrol in the town.

"A car passed our vehicle and parked down the road," he said. "When the foreigners' vehicle was passing this road, it was targeted and there was an explosion."

A spokesman for NATO declined to comment on the attack, referring all questions to the Afghan provincial government.

A statement from the Ministry of Interior said the attack took place near an Education Department building, though Ahmadi initially described it as an aid office. The Ministry said the vehicles in the convoy were about 70 percent destroyed.

No one claimed responsibility for the car bomb, but Helmand has been one of the most volatile areas in the Taliban insurgency's pushback against a U.S.-led initiative to bring southern Afghanistan under greater control of the central Afghan government.

Karzai, who is on a trip meeting European leaders, condemned the attack. A statement from his office Thursday blamed "the enemy of the Afghan people" for the violence, which it called "un-Islamic and against humanity."

Elsewhere, officials said a rocket fired by Taliban insurgents killed a woman and her child in eastern Afghanistan.

Insurgents fired the mortar round during a battle Wednesday with Afghan army soldiers trying to clear militants from a stronghold in Kapisa province's Alasay district, said the provincial governor's chief of staff, Abdul Sabor Wafa.

___

Associated Press reporter Mirwais Khan in Kandahar contributed to this report.

Source: http://us.rd.yahoo.com/dailynews/rss/asia/*http%3A//news.yahoo.com/s/ap/20120126/ap_on_re_as/as_afghanistan

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Conoco says reaches China spill compensation deal (AP)

BEIJING ? ConocoPhillips said Wednesday that it and China National Offshore Oil Corp. reached a $160 million agreement to settle compensation claims from oil spills off northeastern China.

The Houston-based company said in a statement that the two had reached an agreement with China's Ministry of Agriculture over the oil spills last June in the Bohai Sea.

The spills were considered small, especially compared with the Gulf of Mexico spills in 2010, but Conoco, the operator of the Bohai field, still came under intense media criticism in China.

Conoco said the money, 1 billion yuan, would be used "to settle public and private claims of potentially affected fishermen in relevant Bohai Bay communities."

It said 10 percent of the money would go to the company's previously announced fund to improve fishery resources.

The agreement will likely stop a lawsuit that a group of more than 100 Chinese fishermen filed last year seeking compensation from ConocoPhillips China for damage to their sea cucumber catches.

In September, ConocoPhillips announced plans to set up two funds to pay compensation and address environmental problems resulting from the spills.

The government has already ordered the company to stop all production pending a full cleanup and a review to ensure no more oil seeps into the sea.

The oil spill covered about 2,500 square miles (6,200 sq. kilometers) of water surface. It drew attention to pollution in the Bohai region due to industrialization, oil drilling and fast population growth that has decimated sea food and fish stocks and caused frequent red tides.

Sea cucumbers, one of many types of sea product harvested in the Bohai, are sausage-shaped, often spiky marine animals that are viewed as a delicacy by many in Asia.

Source: http://us.rd.yahoo.com/dailynews/rss/science/*http%3A//news.yahoo.com/s/ap/20120125/ap_on_bi_ge/as_china_oil_spill

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