Higher winter temperatures may partially offset heat-related deaths by cutting cold-related mortality-but even so, annual net temperature-related deaths might go up a third. The study, published this week in the journal Nature Climate Change, was done by a team at Columbia University's Earth Institute and the Mailman School of Public Health.

Studies of other cities have already projected adverse health effects from rising temperatures, but this is one of the most comprehensive so far. Unlike many others, it combines data from all seasons, and applies multiple scenarios to a local area-in this case, the most densely populated county in the United States.

"This serves as a reminder that heat events are one of the greatest hazards faced by urban populations around the globe," said coauthor Radley Horton, a climate scientist at the Earth Institute's Center for Climate Systems Research. Horton says that people need look no further for the potential dangers than the record 2010 heat wave that hit Russia, killing some 55,000 people, and the 2003 one that killed 70,000 in central and western Europe.

Daily records from Manhattan's Central Park show that average monthly temperatures already increased by 3.6 degrees Fahrenheit from 1901 to 2000-substantially more than the global and U.S. trends. Cities tend to concentrate heat; buildings and pavement soak it up during the day and give it off at night.

Many records have been set in Manhattan recently; 2012 was its warmest year on record, and in each of the past three years, it has seen temperatures at or above 100 degrees F. Projections for the future vary, but all foresee steep future average increases : 3.3 to 4.2 degrees F more by the 2050s, and 4.3 to 7.1 degrees by the 2080s.

To make mortality estimates, the researchers took temperature projections from 16 global climate models, downscaled these to Manhattan, and put them against two different backdrops: one assuming rapid global population growth and few efforts to limit emissions; the other, assuming slower growth, and technological changes that would decrease emissions by 2040. As a baseline for estimating temperature-related deaths, they used the 1980s, when an estimated 370 Manhattanites died from overheating, and 340 died from cold.

No matter what scenario they used, the projections suggested increased mortality. In the 2020s for instance, numbers produced from the various scenarios worked out to a mean increase of about 20 percent in deaths due to heat, set against a mean decrease of about 12 percent in deaths due to cold.

The net result: a 5 or 6 percent increase in overall temperature-related deaths. Due mainly to uncertainties in future greenhouse emissions, projections for the 2050s and 2080s diverge more-but in all scenarios mortality would rise steeply.

The best-case scenario projects a net 15 percent increase in temperature-related deaths; the worst, a rise of 30-some percent. Assuming Manhattan's current population of 1.6 million remains the same, the worst-case scenario translates to more than 1,000 annual deaths.

The study also found that the largest percentage increase in deaths would come not during the traditionally sweltering months of June through August, but rather in May and September-periods that are now generally pleasant, but which will probably increasingly become incorporated into the brutal dog days of summer.

Senior author Patrick Kinney, an environmental scientist at the Mailman School and Earth Institute faculty member, pointed out several uncertainties in the study.

For instance, he said, things could be made better or worse by demographic trends, and how well New York adapts its infrastructure and policies to a warmer world. On one hand, future Manhattanites may be on average older and thus more vulnerable; on the other, New York is already a leader in efforts to mitigate warming, planting trees, making surfaces such as roofs more reflective, and opening air-conditioned centers where people can come to cool off.

Kinney said there is already some evidence that even as city heat rose during the latter 20th century, heat-related deaths went down--probably due to the introduction of home air conditioning. "I think this points to the need for cities to look for ways to make themselves and their people more resilient to heat," he said.

The lead author of the study is Tiantian Li, an epidemiologist now at the Chinese Center for Disease Control and Prevention in Beijing, who did the work while serving as a postdoctoral researcher at the Columbia Climate and Health Program at Mailman, which Kinney directs.

The paper, "Projections of Seasonal Patterns in Temperature-Related Deaths for Manhattan, New York," is available from the authors or from Nature

]]> Thu, 23 MAY 2013 23:06:14 AEST Moore, Oklahoma (AFP) May 22, 2013 - Seventy-five percent of the world's tornadoes occur in the United States, yet few people who live in "Tornado Alley" bother with the trouble and expense of a proper shelter from the storms.

Mel Evridge, 69, a retired builder who experienced both Monday's twister in this Oklahoma City suburb that killed 24 and a still deadlier one in May 1999, is a proud member of that minority.

Not only did he put a storm cellar in the smart single-level house he built for his family in the 1970s, but he also opted to use Arkansas Hackett stone tough enough to withstand the worst of Oklahoma's climatic extremes.

Even then, Evridge told AFP as he collected debris from his front lawn, "I was just about as scared (Monday) as I was the first time."

"Ever heard a jet throttle up when holding its brakes?" he asked in describing what a tornado feels like from inside a shelter. "That's what it sounded like. Just one big roar."

Yet few homes in the tornado-vulnerable Great Plains that stretch from Texas to the Canadian border are fitted with tornado shelters -- and public buildings even less so.

In the Oklahoma City area, perhaps 10 to 20 percent of homes have some kind of formal shelter, said John Snow, a professor of meteorology at the University of Oklahoma and an authority on the Great Plains' often unforgiving climate.

No state or local law in Oklahoma, the "bullseye" of Tornado Alley, mandates the installation of residential storm shelters -- and homeowners who do opt for them have to shell out upwards of $4,000 for the most basic option.

"Storm shelters are a good idea. That's a fundamental message," Snow told AFP in a telephone interview. "But there are awesome challenges to building them."

Besides the expense, the region's flat open terrain consists of clay, which expands when wet, contracts when dry and renders the kind of basements common in the eastern United States vulnerable to cracking and crumbling.

There's also the fact that tornadoes as potent as those seen in Moore, with winds of 200 miles (321 kilometers) per hour, are few and far between, compared to the far more common ones that are half as strong.

For those twisters at the low end of the five-step Enhanced Fujita scale, taking cover in the bathtub, under a staircase or inside a closet is typically good enough, Snow said.

Schools like Plaza Towers Elementary, in which at least seven children died Monday, also don't require underground shelters. Instead, teachers are trained to huddle their young charges in hallways and other places well away from windows.

In Oklahoma, only about 100 schools have safe rooms built with federal funding that is no longer available, The Wall Street Journal reported.

"Unfortunately, people prefer homes with swimming pools rather than storm shelters," said Oklahoma State Representative Joe Dorman, who is proposing a $500 million state bond issue to pay for more school shelters.

Public buildings like office and shopping complexes are subject to more stringent construction and engineering codes than homes, and so structurally have a better chance of standing up to a tornado, according to Snow.

"If you look closely, all the washrooms (in shopping malls) have little signs that say, 'This is a tornado shelter,'" he said.

Indeed, the Warren multiplex cinema -- part of a western US theater chain whose owner takes pride in the high quality of his real estate -- took the fury of the tornado so well that it was commandeered as a first aid center.

And there's the character of the people who chose to live in Oklahoma, a land of cowboys, oil workers, wide open skies and endless prairie that encapsulates the American ideal of rugged individualism.

"It traces back to the people who settled this part of the country" in the late 1800s, Snow said. "If you didn't like it here, you left. What you have is a pretty tough lot. Come back (to Moore) in 18 months. You'll see it rebuilt."

]]> Thu, 23 MAY 2013 23:06:14 AEST Moore, Oklahoma (AFP) May 22, 2013 - Facing an eye-popping scene of utter destruction, people in this US community turned Wednesday to the towering task of rebuilding their lives after a furious tornado killed at least 24 people.

Officials said most bodies had been recovered from the sprawling moonscape that was once an Oklahoma City suburb, where Monday afternoon's twister steamrolled entire neighborhoods and two schools. Nine children were among those who perished.

After wide fluctuations in the casualty estimates offered by officials, Oklahoma City police chief Bill Citty said 20 people had been killed in the suburb of Moore and four more elsewhere. He said the death toll could rise.

Some 237 people were injured by the hurricane-strength storm, Andy Oden, a spokesman for the Oklahoma Department of Emergency Management, told AFP.

The majority -- 148 -- suffered cuts or piercings while 85 were struck by debris and four by vehicles or other large objects.

As rescue efforts wound down, Homeland Security Secretary Janet Napolitano was headed to Moore Wednesday to "ensure that first responders are receiving the assistance they need," said a statement from her office.

For residents whose lives were turned upside down, relief about having survived turned to heartbreak as the extent of the disaster slowly sunk in.

"It's unreal. It's so visceral," said 32-year-old accountant Roger Graham as he combed through the ruins of the three-bedroom home he shared with his wife Kalissa, a schoolteacher, recovering what he could.

Curtis Carver, a 20-year veteran of the US Marine Corps who served two years in Iraq, described his hometown as a "war zone" as he waited at a police checkpoint for permission to recover keepsakes from the ruins of his house.

"It was my home, my kids' home," said the 38-year-old father of two, both of whom escaped harm. Carver was not allowed past because his house was in an area still deemed too dangerous.

"Now it's gone. There's nothing left. It's a pile of sticks.... and they're keeping me away," he said.

The tornado was the strongest possible category, EF5, packing winds of more than 200 miles per hour (320 kilometers per hour), Kelly Pirtle of the US weather agency's Severe Storms Laboratory in nearby Norman told AFP.

The epic twister, two miles (three kilometers) across, flattened block after block of homes as it struck mid-afternoon Monday, hurling cars through the air, downing power lines and setting off localized fires in a 45-minute rampage.

The epicenter of the tragedy was the Plaza Towers Elementary School, where frightened teachers and students huddled in hallways and bathrooms as the twister barreled through, and where some of the children died.

"I couldn't hear anything but people screaming and crying," Claire Gossett, 11, told The New York Times. "It felt like the school was just flying."

In televised remarks from the White House, US President Barack Obama made special mention of the young victims as he mourned those lost and promised to provide survivors with the help they need to find their footing.

"There are empty spaces where there used to be living rooms and bedrooms and classrooms, and in time we're going to need to refill those spaces with love and laughter and community," Obama said.

Most of the widely scattered debris consisted of splinters of wood no more than a foot (30 centimeters) long and other building debris. Bigger objects were few and far between.

Here and there were touchingly personal items: a bicycle wheel, a baseball mitt, a golf ball, a red Christmas stocking, a black wig.

Volunteers helped residents unearth official paperwork like passports and tax declarations, but also collectibles such as Star Wars memorabilia and part of a coin collection, said Michael Albrecht, who was in town for a company meeting when the tornado struck and decided to help the recovery.

Monday's tornado followed roughly the same track as a May 1999 twister that killed 44 people, injured hundreds more and destroyed thousands of homes.

Tornadoes often stalk Oklahoma's wide open plains, but Monday's twister struck a populated urban area. Because of the hard ground, few homes here are built with basements or storm shelters in which residents can take cover.

But that could change going forward, with Moore Mayor Glenn Lewis telling CNN he would push for an ordinance mandating storm shelters or safe rooms in new single and multi-family homes.

Oklahoma City lies inside the so-called "Tornado Alley" stretching from South Dakota to central Texas, an area particularly vulnerable to tornadoes.

]]> Thu, 23 MAY 2013 23:06:14 AEST Moore, Oklahoma (AFP) May 22, 2013 - Two babies are among the 24 people killed by a tornado that tore through this US community, officials said Wednesday, as residents began the daunting task of rebuilding their lives.

Ten children -- including a pair of infants four and seven months old -- perished in Monday's fierce twister that steamrolled entire neighborhoods and two schools in the Oklahoma City suburb of Moore.

"Our hearts go out to all the people affected by this tragedy," Amy Elliott of the state medical examiner's office said in an email detailing the revised breakdown of the official death toll. Previously, authorities had put the number of child fatalities at nine.

President Barack Obama will visit the ravaged region on Sunday to meet with victims and get a firsthand look at the stunning, widespread damage of an area that was previously razed by a still deadlier tornado in May 1999.

The preliminary causes of death for the two dozen casualties included blunt force traumas, as well as asphyxiation, according to the Oklahoma Medical Examiner's Office, which also released some of their names. Both babies died of head trauma.

Some 237 people were injured by the hurricane-strength storm, Oklahoma Department of Emergency Management spokesman Andy Oden told AFP.

It was not immediately clear if anyone remains unaccounted for, with Governor Mary Fallin urging everyone affected to come forward.

"We need to know where you're at. We need to know if you need assistance," she said.

During a visit to tour the damage, Homeland Security Secretary Janet Napolitano pledged government support for those struggling to piece their lives back together.

"At some point the cameras will leave, the national ones will leave first, then the local ones," she said. "But on behalf of President Obama and on behalf of (the Federal Emergency Management Agency), we will be here to stay until this recovery is complete."

Moore Mayor Glenn Lewis vowed to propose an ordinance in the coming days at the local city council to require the construction of tornado shelters in new homes, and expressed confidence he would get the necessary votes for the measure.

Fallin, the governor, agreed on CNN that it was "certainly wise" to install safe rooms, particularly in schools.

No state or local law in Oklahoma, the "bullseye" of Tornado Alley, mandates the installation of residential storm shelters -- and homeowners who do opt for them have to shell out upwards of $4,000 for the most basic option.

As a result, few people who live in "Tornado Alley" bother with the trouble and expense of a proper shelter from the storms.

For residents whose lives were turned upside down, relief about having survived turned to heartbreak as the extent of the disaster slowly sunk in.

Curtis Carver, a 20-year veteran of the US Marine Corps who served two years in Iraq, described his hometown as a "war zone" as he waited at a police checkpoint for permission to recover keepsakes from the ruins of his house.

"It was my home, my kids' home," said the 38-year-old father of two, both of whom escaped harm. Carver was not allowed past because his house was in an area still deemed too dangerous.

"Now it's gone. There's nothing left. It's a pile of sticks... and they're keeping me away," he said.

The tornado was the strongest possible category, EF5, packing winds of more than 200 miles (320 kilometers) per hour, Kelly Pirtle of the National Weather Service's Severe Storms Laboratory in nearby Norman told AFP.

The epic twister, two miles across, flattened block after block of homes as it struck, hurling cars through the air, downing power lines and setting off localized fires in a 45-minute rampage.

The epicenter of the tragedy was the Plaza Towers Elementary School, where frightened teachers and students huddled in hallways and bathrooms as the twister barreled through, and where some of the children died.

]]> Thu, 23 MAY 2013 23:06:14 AEST Moore, Oklahoma (AFP) May 21, 2013 - For years Anita Zhang's neighbors joked that if a tornado ever bore down on her Chinese restaurant, folks could take refuge in its roomy walk-in freezer.

On Monday, Zhang got the chance to test their idea -- and to live to tell the tale -- when one of the most powerful and destructive twisters to hit the United States in recent years ripped through this Oklahoma City suburb.

"I'm so lucky," she said, over and over, as she told her story to AFP through an interpreter Tuesday in the driveway of her home in another section of Moore that escaped the tornado's raw fury.

A native of Guangdong, the southern Chinese province that's no stranger to merciless typhoons, 57-year-old Zhang emigrated to the United States 10 years ago with other members of her family.

She opened the Hong Kong Chinese Restaurant on Southwest 19th Street seven years ago in a commercial strip mall that catered to Moore's many handsome middle-class residential developments.

It had a good reputation for such dishes as spicy fried General Tso chicken. "Great food at a great price," wrote one Google reviewer. "Very nice family-owned restaurant. The food is excellent. Service is quick."

Monday's tornado -- which police say killed at least 24 people with its 200 mile (320 kilometer) per hour winds cutting a 17 mile (27 kilometer) swath through Moore -- was quick, too.

She was watching live storm coverage on local TV in the restaurant with her brother Michael Zhang, 50, when suddenly the power went off, the neighborhood disaster sirens wailed and the dark funnel of fury drew near.

Into the freezer the siblings went -- with a blanket, thoughtfully -- to sit out the twister as it passed literally on top of them, pulverizing everything in its path.

"I thought it was an earthquake," recalled the Cantonese-speaking Zhang, whose Mandarin Chinese name is Zhang Jianci.

"I felt the building was shaking and moving. There were loud noises and banging and wind blowing... I thought only the glass door of the restaurant would be broken, but when we crawled out, everything was gone."

Initially, the Zhangs struggled to open the freezer door against the debris.

Michael was first to wiggle out; Anita was too scared to follow, until her brother announced that nearby buildings were on fire.

Once out of the freezer, Anita Zhang heard people shouting: "Anyone there?" Later, she learned from her daughter that it was the neighbors, coming to check on their safety.

Zhang's misfortune was for the business her immigrant family had toiled so hard to build to be literally on the wrong side of Southwest 19th Street, which turned out to be the southern edge of the tornado's scalpel-like track.

On the north side of the street, besides the restaurant, the tornado smashed the entire Camden Village strip mall, including a liquor store that Tuesday reeked of broken bottles of booze, as well as a Walgreen's drug store.

On the opposite side, however, a rival CVS pharmacy got off unscathed -- so much so that it re-opened for business. An adjacent low-rise apartment complex likewise sustained no serious damage.

"We stood in the windows and watched it (the tornado) coming in," recounted Karen Smith, who works at the apartment complex. She and daughter Elizabeth then rode out the storm under a staircase, snuggling up with their dachshund Lucy.

Police denied access to non-residents Tuesday to the worst-hit residential streets in Moore, but the startling scale of the destruction was all too visible from the sidelines.

Zhang's family returned to the restaurant Tuesday to recover whatever they could salvage -- sacks of white rice, cans of vegetables, a barrel of MSG -- for safekeeping in the two-car garage back at home.

Longer term, Zhang would like the Hong Kong Chinese Restaurant to reopen.

It was insured, she said, although 24 hours after disaster struck, the family is still coming to grips with everything that's happened so suddenly.

For now, she's more than content that her two granddaughters are unhurt. Their mother, who is Zhang's daughter, took them out of school before the tornado got too close and drove off with them to safety.

"They are back now," she said with a sigh of relief. "They are alive."

]]> Thu, 23 MAY 2013 23:06:14 AEST Washington (AFP) May 21, 2013 - The massive tornado that cut a wide and deadly swath through a suburban Oklahoma City town was a top category EF5 system with winds over 200 mph (321 kmh), a weather official told AFP Tuesday.

"It's an EF5," the most powerful tornado classification, said Kelly Pirtle of the NOAA national Severe Storms Laboratory in Norman, Oklahoma, of the wedge tornado that struck Moore, Oklahoma on Monday.

"We have looked at the damage, and estimated windspeeds, and they've determined that the damage is EF5," she added by phone from Norman.

That means the system, which blew homes off their foundations and sent debis flying almost 100 miles away, had "maximum winds over 200 miles per hour," Pirtle explained.

Rescue teams were still combing through a blasted moonscape that had been Moore after the monstrous tornado struck south of Oklahoma City, killing at least 24 people.

Passengers flying into Oklahoma City could see the track left nature's fury as it played out Monday: the spot where the tornado touched down then chewed through the suburb of Moore like a lawnmower for 45 terrifying minutes.

Nine children were among the dead and entire neighborhoods were obliterated.

Moore tornado a rarity: experts
Paris (AFP) May 21, 2013 - Tornados, among the most violent of atmospheric storms, rarely reach the size and brutality of the twister that swept through an Oklahoma City suburb on Monday, experts say.

And seldom do they hit built-up areas.

"Typically, they could be about 100 metres (110 yards) across, and they last maybe five to ten minutes on the ground," according to University of Reading meteorologist Ross Reynolds -- who said the people of Moore were in many ways unlucky.

They were confronted by a two-mile- (three-kilometre) wide storm that lasted about 45 minutes and was of a similar strength to the worst-ever tornado that hit the area 14 years ago but claimed fewer lives.

"It is bad luck that a tornado goes in a populated area, normally it is agriculture land... crops or farm buildings," said Reynolds.

"It is a horrible thing when they go through the cities -- the chances of that happening are very small" -- especially in such a sparsely populated region.

Revising a previous higher toll, officials said Tuesday that at least 24 people, including nine children, had died in the Oklahoma storm that packed winds of 166 to 200 miles per hour (267-322 kilometres per hour).

Tornados are spinning columns of air that touch the ground from massive cumulonimbus thunderstorm clouds.

They occur in regions of most continents except for the very coldest areas, and are also common in Argentina and Bangladesh.

The UK is said to get more tornadoes per square kilometre than the United States, but the central and southern American states of Texas, Oklahoma and Kansas get the most violent ones due to unique geographical and meteorological conditions.

Dubbed "Tornado Alley", this is where winds of widely varying temperatures -- warm and moist from the Gulf of Mexico, hot and dry from the desert and cool and dry from the Rocky Mountains and northern plains -- meet in volatile, potent storm clouds called "supercells" that can explode as tornadoes within half an hour from birth.

Most storms occur from May to June, and mainly between 4 pm and 9 pm, according to the US National Oceanic and Atmospheric Administration.

Tornado Alley can see three or four tornados per day in the high season, or about 1,200 for the entire country per year, but only about two percent reach dangerous levels with winds exceeding 265 kph and most of these hit land in rural areas.

According to Reynolds, weather conducive to tornado formation can be predicted a day in advance.

Local forecasters can then keep a careful eye on satellite and radar pictures of cloud- and rain-formation -- send out tornado-spotters to find the storms and estimate their speed and destination.

This allows officials to issue a 15-20-minute warning, hopefully enough time to dive into a tornado centre.

Experts say accurate records are too young and tornadoes too small and sporadic to predict whether they are likely to be impacted by climate change.

There was no proof that they were becoming more frequent or severe, said Reynolds.

"Climate models are currently unable to resolve small-scale phenomena such as tornadoes, and no models exist which can use climate model data to predict future tornado activity," said the UK Met Office.

But Andrew Barrett, also from the University of Reading, said warmer, moister conditions should "provide more energy for the types of storms that produce tornadoes in a warmer climate."

]]> Thu, 23 MAY 2013 23:06:14 AEST Washington (AFP) May 21, 2013 - A powerful tornado swept through an Oklahoma City suburb on Monday, tearing down blocks of homes, two schools and leaving up to 91 people dead, including 20 children, local officials said.

US President Barack Obama declared a "major disaster" as rescuers combed through smashed homes and the collapsed remains of an elementary school in Moore, where twister-seasoned residents were shocked by the devastation.

Stunned weather forecasters reported a two-mile (three-kilometer) wide swath of vicious winds, and news helicopters tracked a dark funnel plowing through densely packed suburbs near the capital of the Midwestern state of Oklahoma.

"We've had a massive tornado, a huge one that has passed through this community," Oklahoma Governor Mary Fallin told a news conference shortly after the mid-afternoon storm, which struck near the end of the school day.

"We know there are a lot of injuries. We know we've lost a tremendous amount of structures throughout this community and throughout the state," she said, as the Moore police chief urged people to leave the area.

The dead included at least 20 children, most of them under the age of 12, Amy Elliott, of the state medical examiner's office, told AFP.

She later said she could not confirm a rise from an earlier official toll of 51 but that she had been told to prepare for 40 more bodies.

CNN reported that at least 145 people had been hospitalized.

Reporters for local broadcaster KFOR-TV saw children as young as nine being pulled out of the Plaza Towers Elementary School in Moore, a residential community of 55,000 just south of Oklahoma's state capital.

Anxious parents were being kept at a distance while search-and-rescue workers scrambled to free the students.

A second elementary school, Briarwood, was also hit but did not appear to have suffered casualties.

From its news helicopter, KFOR's cameras captured scenes of widespread destruction, with street after street of single-story homes in Moore stripped of their roofs and cars piled atop each other like toys.

Utility lines were down and gas lines exposed, triggering localized fires. The Moore Medical Center was evacuated after it sustained damage, and state authorities called out the National Guard to help rescue efforts.

Obama ordered federal aid to supplement local recovery efforts.

On Twitter, the National Weather Service gave the tornado a preliminary rating of EF-4, indicating that it packed winds of 166 to 200 miles per hour (267-322 km/h) -- more severe than a category five hurricane.

In downtown Oklahoma City, tornado sirens went off at least three times and the Interstate 35 highway -- a busy north-south artery through the American heartland -- was closed to all but emergency vehicles.

In Moore, live images from KFOR showed people wandering among the debris and even a couple of untethered horses from a local stable that somehow managed to survive the punishing storm.

"I had no idea it was coming," said a stable worker, who told how he survived the "unbearably loud" twister by taking cover in one of the stalls.

Monday's tornado followed roughly the same track as a May 1999 twister that killed 44 people, injured hundreds more and destroyed thousands of homes.

Tornadoes frequently touch down on Oklahoma's wide open plains, but Monday's twister struck a populated urban area and raised fears of a high casualty toll.

Because of the hard ground, few homes are built with basements or storm shelters in which residents can take cover.

Oklahoma City lies inside the so-called "Tornado Alley" stretching from South Dakota to central Texas, an area particularly vulnerable to tornadoes.

But Moore's residents were shocked at the sprawling moon-like landscape left behind by the massive twister.

"There's nothing left of my house," an unidentified woman told CNN.

"The front is still standing but the back is gone. My bathroom honestly is untouched. We've lost animals. We've lost everything," she said.

Some 35,000 people remained without power early Tuesday, according to OG&E, the local utility.

On Sunday, a powerful storm system churning through the US Midwest spawned tornadoes in Iowa, Kansas and Oklahoma, destroying homes and killing at least two people, US media reported.

Fallin had already declared a state of emergency for 16 Oklahoma counties due to the tornado threat on Sunday, and added five more on Monday after the storms hit her capital.

]]> Thu, 23 MAY 2013 23:06:14 AEST Washington (AFP) May 16, 2013 - Ten tornadoes tore through the US state of Texas overnight, killing at least six people and injuring dozens as they leveled homes and downed power lines, local authorities said Thursday.

As day broke, first responders were still searching for survivors in the north of the state, in particular in the small town of Granbury in Hood County, Sergeant Nathan Stringer, a North Texas public information officer, told AFP.

"There were an estimated 10 tornadoes which occurred over North Texas last night," Stringer said in an email. "It is still unknown how many total communities were affected however, there was a large portion of Hood County and the City of Granbury affected."

About 53 people were injured and roughly seven are still unaccounted for, he added.

Hood County Sheriff Roger Deeds stressed that finding survivors was a top priority.

"The main concern is life safety and finding victims that still need our help," Deeds told reporters.

The Rancho Brazos subdivision was especially hard hit and it was there that all the deaths occurred, he said.

"That whole subdivision was affected. All the streets out there."

Pastor Dean Porter of the Lake Granbury Christian Temple watched one of the twisters take shape.

A "funnel cloud began to form, and ... the debris was being pulled up into a rotation," he told CNN. "Power lines were pulled down into the road. It was amazing. It was devastating."

The Dallas Morning News ran photos overnight of swirling dark blue masses in the sky, homes damaged by fallen trees and an 18-wheel truck tipped over onto a compact car.

As the sun came up Thursday, aerial video showed scenes of devastation, including demolished houses.

Hood County is southwest of Dallas.

The National Weather Service warned that more tornadoes were possible Thursday afternoon and evening across parts of the United States, including northeastern Texas.

]]> Thu, 23 MAY 2013 23:06:14 AEST Berkeley CA (SPX) Apr 17, 2013 - NASA has awarded the University of California, Berkeley, up to $200 million to build a satellite to determine how Earth's weather affects weather at the edge of space, in hopes of improving forecasts of extreme "space weather" that can disrupt global positioning satellites (GPS) and radio communications.

The satellite mission, called the Ionospheric Connection Explorer (ICON), will be designed, built and operated by scientists at UC Berkeley's Space Sciences Laboratory. Scheduled for launch in 2017, ICON will orbit 550 kilometers (345 miles) above Earth in the ionosphere: the edge of space where the sun ionizes the air to create constantly shifting streams and sheets of charged particles. These charged particles can interfere with GPS signals and radio signals that bounce off the ionosphere.

ICON will collect data needed to establish the connection between storms that occur near Earth's surface and space-weather storms, allowing scientists to better predict space weather. These results could help airliners, for example, which today cannot rely solely on GPS satellites to fly and land because signals from these satellites can be distorted by charged-particle storms in the ionosphere.

"Ten years ago, we had no idea that the ionosphere was affected and structured by storms in the lower atmosphere," said the project's principal investigator, Thomas Immel, a senior fellow at the Space Sciences Laboratory. "We proposed ICON in response to this new realization."

NASA announced the award last week, along with another mission called the Global-scale Observations of the Limb and Disk (GOLD), which will image Earth's thermosphere and ionosphere from a commercial geosynchronous satellite.

"One of the frontier areas of heliophysics is the study of the interface between outer space and the upper reaches of Earth's atmosphere," said John Grunsfeld, NASA associate administrator for science at NASA Headquarters in Washington, D.C. "These selected projects use innovative solutions to advance our knowledge of this relatively unexplored region. The two missions together will result in significantly more advances in our understanding of Earth's atmosphere and ionosphere than either would alone."

Until recently, Immel said, the ionosphere was thought to be affected primarily by solar wind - particles emitted from the sun - that scours the upper atmosphere. When the sun is active and firing bursts of charged particles toward Earth, the ionosphere erupts in chaotic storms. But a slew of satellites orbiting Earth to study the sun, solar wind and Earth's magnetic field have now shown that Earth's space environment, specifically activity in the ionosphere, can't be explained solely by particles streaming from the sun.

"We know that the solar wind plays a big role in the ionosphere, but most of the time the sun is relatively quiet, and our space environment still varies quite a bit," he said. "We think that variability is coming from weather on our own planet, which can be very powerful."

This can happen, Immel said, when surface storms compress and heat the atmosphere, driving huge waves upward into space and causing charged particles to move across magnetic fields in unpredictable ways. This can also lead to extreme fluctuations of temperature in the ionosphere.

"There are huge waves at an altitude above 100 kilometers (63 miles), with amplitudes as large as 50 degrees Kelvin, where the average temperature is about 300 degrees Kelvin (77 degrees Fahrenheit) - a 20-30 percent variation," he said. "That may sound small, but imagine a wave rolling through your neighborhood with a temperature swing of 100 degrees Kelvin, or 180 degrees Fahrenheit - from freezing to boiling! These waves can change the composition of the upper atmosphere and how the ionosphere grows during the day."

ICON will explore these and other processes that control the dynamics and chemistry of the upper atmosphere and ionosphere. One issue, for example, is why "North America is, in a way, like tornado alley for space," Immel said, where huge masses of ionized plasma roll over the country and disrupt GPS and other communications.

"We want to understand where this plasma comes from - Is it generated in situ? Does it grow in outer space? Or are we pulling plasma up from lower latitudes like the Caribbean?" he said.

The satellite will operate in a circular orbit tilted 27 degrees from the equator and simultaneously map winds in the upper atmosphere and charged particle currents, called plasmas, in the ionosphere, a region that stretches from an altitude of about 85 to 600 kilometers (50 to 370 miles).

The instrument called MIGHTI (Michelson Interferometer for Global High-resolution Thermospheric Imaging), which will be built by scientists at the Naval Research Laboratory, will detect the aurora-like glow of air molecules and measure their temperature and speed via Doppler imaging. These winds routinely blow at 200 miles per hour in a part of the upper atmosphere called the thermosphere.

Two other instruments built at UC Berkeley's Space Sciences Laboratory will simultaneously image the upper atmosphere in the far and extreme ultraviolet, while a fourth instrument from the University of Texas, Dallas, will measure the charged particles and flowing plasma at the location of the satellite.

"ICON's imaging capability, combined with its in situ measurements on the same spacecraft, gives a perspective of the coupled system that would otherwise require two or more orbiting observatories," he said.

UC Berkeley will control the spacecraft from its Mission Operations Center at the Space Sciences Laboratory, which currently operates the satellite missions THEMIS, ARTEMIS, RHESSI and NuSTAR, all NASA Explorer missions, and recently operated the FAST Explorer.

NASA is funding ICON through the Explorer program, the agency's oldest continuous program, designed to provide frequent, low-cost access to space for principal investigator-led space science investigations relevant to the heliophysics and astrophysics programs in NASA's Science Mission Directorate in Washington.

]]> Thu, 23 MAY 2013 23:06:14 AEST Buenos Aires (AFP) April 2, 2013 - At least eight people died after torrential rain and strong winds battered Buenos Aires and its suburbs, knocking out power, downing trees and affecting 350,000 residents, officials said Tuesday.

More than six inches (155 mm) of rain fell between midnight Monday and 7 am Tuesday, the city weather service said, setting an April record for the Argentine capital.

One of the dead was a subway worker electrocuted while trying to pump water out of a flooded station, union official Enrique Rosito said.

Other victims included three men and two women killed in flooding and other damage caused by the storm, said Alberto Crescenti of the emergency medical service SAME.

Federal police reported two more fatalities.

Some 350,000 people were impacted by the deluge, Mayor Mauricio Macri told a televised news conference.

Flash flooding was worst in northern parts of the city, where widespread construction over the past decade has not been matched by upgrades to the drainage system, environmentalists said.

It was here that about 300 people were evacuated from a slum, Macri said.

The storm and flooding knocked out electricity, sent cars floating down streets, damaged poorly built homes, knocked out power and forced suspension of train service.

About 14 million people live in Buenos Aires and surrounding areas.

A weather alert remains in effect for the metropolitan area through Thursday.

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