Posts Tagged ‘NASA’

Antarctic Ice Melting Faster Than Thought

Wednesday, May 16th, 2012

In a sign that global warming is a reality, a new study reveals that ice shelves in western Antarctica are melting at a faster pace than previously known. Data collected by a NASA ice-watching satellite show that the ice shelves are being eaten away from below by ocean currents, which have been growing warmer even faster than the air above.  Launched in January of 2003, NASA’s ICESat (Ice, Cloud and Land Elevation Satellite) studied the changing mass and thickness of Antarctica’s ice from polar orbit.  An international research team used more than 4.5 million surface height measurements collected by ICESat’s GLAS (Geoscience Laser Altimeter System) instrument between October of 2005 and 2008.  The conclusion was that 20 of the 54 shelves studied — nearly half — were losing thickness.

Melting of ice by ocean currents can take place when air temperature remains cold, maintaining a steady process of ice loss — and ultimately a rise in the sea level.  “We can lose an awful lot of ice to the sea without ever having summers warm enough to make the snow on top of the glaciers melt,” said Hamish Pritchard of the British Antarctic Survey and the study’s lead author.  “The oceans can do all the work from below.”  The study also found a shift in Antarctica’s winds as a result of climate change.  “This has affected the strength and direction of ocean currents,” Pritchard said.  “As a result warm water is funneled beneath the floating ice.  These studies and our new results suggest Antarctica’s glaciers are responding rapidly to a changing climate.  We’ve looked all around the Antarctic coast and we see a clear pattern: in all the cases where ice shelves are being melted by the ocean, the inland glaciers are speeding up.  It’s this glacier acceleration that’s responsible for most of the increase in ice loss from the continent and this is contributing to sea-level rise.”

Antarctica contains adequate ice to raise sea levels by approximately 187 feet, although it’s unlikely to melt for thousands of years, according to the United Nations.  Some ice shelves are thinning by a few meters a year, and glaciers in response are draining billions of tons of ice into the sea, Pritchard said.  “Most profound contemporary changes to the ice sheets and their contribution to sea level rise can be attributed to ocean thermal forcing that is sustained over decades and may already have triggered a period of unstable glacier retreat.”

Some ice shelves are thinning just a few feet a year, and glaciers drain billions of tons of ice into the sea as a result.  “This supports the idea that ice shelves are important in slowing down the glaciers that feed them, controlling the loss of ice from the Antarctic ice sheet,” Pritchard said.

While conducting the study, the researchers measured how ice shelf height changed, using computer models to check changes in ice thickness due to natural snow accumulation.  Additionally, they used a tide model that eliminated height changes due to rising tides.  “This study shows very clearly why the Antarctic ice sheet is currently losing ice, which is a major advance,” said Professor David Vaughan, the leader of ice2sea.  The study is significant because it shows the key to predicting how an ice sheet might change in the future.  “Perhaps we should not only be looking to the skies above Antarctica, but also into the surrounding oceans,” Vaughan added.

Tom Wagner, cryosphere program scientist at NASA, said that the study demonstrates how “space-based, laser altimetry” can expand scientists understand of the earth.  “Coupled with NASA’s portfolio of other ice sheet research using data from our GRACE mission, satellite radars and aircraft, we get a comprehensive view of ice sheet change that improves estimates of sea level rise.”

“When ice shelves completely collapse — and we’ve seen that before — the grounded glaciers behind them will speed up; we know that,” said co-author Helen Amanda Fricker of Scripps Institution of Oceanography at the University of California San Diego.  “But what this study is showing, which is very new, is that you don’t need to lose the shelf entirely for this to happen; just a reduction in the thickness of the ice shelf is enough to allow more of the grounded ice behind it to flow off the continent.”

Experts Agree (Sort of): 2011 Was One of the Warmest Years on Record

Monday, January 30th, 2012

Depending on who you listen to, 2011 was either the 11th warmest on record — that’s according to the National Oceanic and Atmospheric Administration (NOAA) or the 9th — according to the National Aeronautic and Space Administration — NASA.

According to scientists at NOAA, 2011 broke records for climate extremes, as much of the United States faced historic levels of heat, precipitation, flooding and severe weather.  This was driven in part by La Niña events at both ends of the year that impacted weather patterns in the United States and around the world.  NOAA’s annual analysis of U.S. and global conditions, conducted by scientists at NOAA’s National Climatic Data Center, reports that the average temperature for the contiguous 48 states was 53.8 degrees F, 1.0 degree F above the 20th century average, making it the 23rd warmest year on record.  Rain from coast to coast averaged near normal, despite record-breaking extremes in both drought and precipitation.

Kathryn Sullivan, assistant secretary of commerce for environmental observation and prediction and deputy NOAA administrator, described 2011 as an “extraordinary year.”  “It was extraordinary regarding major weather and climate disasters in particular in our country, from tornadoes to droughts to floods and extreme storms,” she said.  “America endured an unusually large number of extreme events causing damages totaling more than $55 billion dollars.”

By contrast, NASA research counters that 2011 was the 9th warmest year since records were first taken in 1880.  In fact, since that year, nine of the 10 warmest years on record have been in the decade since 2000, a rise in global temperature is evident. The only of the 10 warmest years that was not during the past decade was in 1998. Meanwhile, 2010 is still the warmest year on record overall.  The data was gathered from more than 1,000 meteorological stations across the globe.  NASA estimates that over the next few years we’ll see a year that will top 2010’s record breaking temperatures.  “It’s always dangerous to make predictions about El Niño, but it’s safe to say we’ll see one in the next three years,” James E. Hansen, director of NASA’s Goddard Institute for Space Studies, said. “It won’t take a very strong El Niño to push temperatures above 2010.”

According to NASA scientists, 2011 demonstrated a continuing strong trend linked to greenhouse gases.  NASA noted that the current warmer temperatures are primarily sustained by increased concentrations of greenhouse gases in the atmosphere, especially carbon dioxide. Carbon dioxide is created by a variety of human activities, such as coal-fired power plants to fossil-fueled vehicles to human breath.  At present, levels of carbon dioxide in the atmosphere exceed 390 parts per million (ppm), compared with 285 ppm in 1880 and 315 by 1960, according to NASA.

Writing in The Atlantic, Rebecca J. Rosen says that “In 1880, when the study’s temperature record-keeping begins, the concentration of carbon dioxide was 285 parts per million. Today it is more than 390 parts per million and rapidly rising. Many top climate scientists, including NASA’s James Hansen, have argued that a level not exceeding 350 parts per million is necessary ‘if humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted.’”

Temperatures Rising in America’s Freshwater Lakes

Wednesday, August 10th, 2011

The waters of the Great Lakes are warmer than usual this year, prompting scientists to worry that this may not be a good thing.  All five Great Lakes have been at or near record-high temperatures compared with the 30 years when such measurements have been taken.  The bad news is that there’s still a month remaining before the lakes typically reach their warmest temperatures.  Jay Austin, a physics professor at the Large Lakes Observatory in Duluth, MN, says the water is warmer because last winter there was little or no ice cover to reflect sunlight.   Scientists are unsure if it’s a blip or the new normal.  A warmer Lake Superior might be a plus for the tourism industry, but it might be bad for fishing, wildlife habitat and water levels.

“Swimmers are enjoying it,” said Al Oleksuik, who lives near the Welland River in Chippewa.  “I notice a difference here.  (The water is 24 C). It usually doesn’t hit that until mid-August. I have a feeling we’re headed towards (26 C), which is extremely warm.”  Austin said the lake is 5 to 7 C warmer than it usually is in mid-July, while the Great Lakes in general are running 2 to 7 C warmer.  “It’s going to set records, or come close, depending on where you are,” he said.

Writing in Chimes, a publication of Grand Rapids-based Calvin College, Geneva Langeland says that “Lake Michigan is warming up?  Swimmers who brave the lake’s often frigid waters might beg to differ.  But Lake Michigan’s waves aren’t alone in their slight temperature uptick; NASA satellite data suggest that lake temperatures worldwide have risen in the last 25 years, most likely as a result of global climate change.  Phillip Schneider and Simon Hook, researchers at NASA’s Jet Propulsion Laboratory in California, departed from the typical strategy of measuring global warming trends by gauging air temperatures near Earth’s surface.  Instead, the study, published in the 2010 issue of Geophysical Research Letters, used infrared satellite imagery to track changing surface temperatures in 167 large lakes splashed across the globe — including our very own Great Lakes.  The satellite data suggest that, over the past 25 years, water temperatures in large lakes have risen between .81 and 1.8 degrees Fahrenheit per decade.  These shifting temperatures varied widely among continents and hemispheres.”

According to Langeland, “Schneider and Hook noted the greatest change in northern Europe; in general, the loftier latitudes of the Northern Hemisphere consistently reported the largest temperature upticks.  The Great Lakes land squarely in that northern region.  Huron, Superior, Michigan, Erie and Ontario together comprise the world’s largest freshwater lake system.  It should come as no surprise that the ‘Big Five’ were valuable players in this study.  In fact, the Great Lakes host nine temperature-gauging buoys that were vital in verifying NASA’s satellite temperature readings.  As Schneider said, ‘The results have implications for lake ecosystems, which can be adversely affected by even small water temperature changes.’  A degree or two might be imperceptible to us, but this tiny change can have surprising repercussions.  Every organism thrives within a particular temperature range.  Altering a habitat’s air and water temperatures even slightly will kill off some creatures while allowing others to unexpectedly thrive.”

Lakes in the American West are experiencing similarly increasing temperatures.  Warming that meets statistical significance was found in Lake Tahoe along the California-Nevada border; Pyramid Lake in Nevada; and the Great Salt Lake in Utah, which were warming at a rate of more than one degree Fahrenheit per decade.  “One of the things we want to do in the future is compare these results with what the climate models predict in the region,” Hook said.  “Measuring a model’s performance in replicating changes of the recent past gives scientists a way to test the accuracy of the models being used to project future conditions.”

“Our analysis provides a new, independent data source for assessing the impact of climate change over land around the world,” Schneider said. “The results have implications for lake ecosystems, which can be adversely affected by even small water temperature changes.”

Atlantis Landing Marks the End of the Legendary Space Shuttle Program

Monday, August 1st, 2011

With the safe landing in Florida of Atlantis, NASA’s ambitious 30-year space shuttle program has officially come to an end.  Immediately after landing, Chris Ferguson,  the Atlantis commander, lauded the shuttle program and the rest of the spacecraft fleet.  “The space shuttle has changed the way we view the world and it’s changed the way we view our universe,” he said.  “There are a lot of emotions today, but one thing is indisputable. America’s not going to stop exploring. Thank you Columbia, Challenger, Discovery, Endeavour and our ship, Atlantis. Thank you for protecting us and bringing this program to such a fitting end.”

Charles Bolden, a former astronaut who currently is the NASA administrator, preferred to look ahead.  “At today’s final landing of the space shuttle, we had the rare opportunity to witness history,” he said.  “We turned the page on a remarkable era and began the next chapter in our nation’s extraordinary story of exploration.  This final shuttle flight marks the end of an era, but today we recommit ourselves to continuing human spaceflight and taking the necessary and difficult steps to ensure America’s leadership in human spaceflight for years to come.”

The United States ended the space shuttle program once the International Space Station, which was half-built at the time, was finished, a goal that was achieved this year.

“Every vehicle has its life,” said Atlantis astronaut Sandy Magnus.  “We’ve known the shuttle is going to retire for a very long time. Knowing this was the normal plan, you want to celebrate the shuttle. You want to acknowledge all the hard work that people have done for 30 years because it is an important part of our country.  It’s hard to say goodbye,” she added. “It’s like saying goodbye to an old friend.”  The space station, an orbital research outpost, is a $100 billion project of 16 nations that was finished this year after more than 10 years of construction.

Writing in the Las Vegas News-Sun, Steve Sebelius says that “On paper, NASA’s next goal is to land astronauts on an asteroid by 2025, and then Mars in the middle of the 2030s.  That’s a long time, by any calculation.  Yes, we’re facing the worst deficits and debt in the nation’s history.  And yes, space exploration is expensive.  (Although perhaps not as much as you think: The Associated Press recently reported that the entire 30-year shuttle program — all 135 missions — cost $196 billion, or about $1.45 billion per mission.  By contrast, a recent Pentagon spending bill approved by the House for a single year was $649 billion, or more than three times as much.)”

Unfortunately, the end of the space shuttle program does not come without some layoffs at the Kennedy Space Center at Cape Canaveral. Approximately 9,000 people who work for NASA contractors will lose their jobs, said Denise Beasley, a spokeswoman for Brevard Workforce, a county agency that helps space employees find new positions.  Five graduates of the class of 1975 at Astronaut High School in Titusville, 12 miles from the space center, have few prospects.  “We’re all 54 years old, and we should be able to relax, and instead we’re all starting over,” said Tish Lawing, whose husband works for a firm that helps remove shuttle waste; her father worked in the space center’s launch-control center.  “This is going to be a ghost town.”  Titusville, a city of 43,761 and neighboring Melbourne promote themselves as located on the 72- mile “Space Coast.”  Home prices, already falling with the national housing bubble, will be “exacerbated” by the shuttle’s end, Moody’s Investors Service said.

NASA intends to use private companies to replace some of the functions of the shuttle program.  A launch under that system is unlikely before 2015, William H. Gerstenmaier, Associate Administrator for Space Operations, said.

Writing on the DVice website, Raymond Wong says that “Never one to miss the chance to boast about its own space achievements, Russia officially sounded off the sirens with a declaration that human space travel is now in the “era of the Soyuz.”  The official statement put out by Russia’s space agency Roskosmos said, ‘From today, the era of the Soyuz has started in manned space flight, the era of reliability.’  Is that a dig at the Shuttle program?

It sure sounds like one.  For those who don’t know much about Russia’s Soyuz rockets, here’s the quick low-down: they’re basically vertical rocket and capsule systems that have been around since the early 1960s, parachuting back to safety upon returning to Earth instead of landing on a runway, like the shuttle.  Of course, The Soyuz capsule isn’t the same one from the ’60s — Russia has made improvements.  Without a means to transport humans back into space (until 2016, at least), the U.S.’s only solution will be to piggyback on a Russian Soyuz rocket, wait to see how that modified Atlas V rocket works or how the private sector will step in.”

There is significant disagreement over the decision to end the space shuttle program.  In an Op-Ed piece in the Chicago Tribune, Storer H. Rowley writes that “English poet Robert Browning wrote that a person’s ‘reach should exceed his grasp.’  That’s always been the story of America, from our pioneers to our astronauts.  Exploration is in our DNA.  We have been reaching for the stars for more than half a century in space-faring alone, limited only by our collective imagination, the dangers of highly experimental space missions and the constraints of earthbound budgets.  Yet, with space shuttle Atlantis returning from its final 13-day mission to the International Space Station, there is no specific national plan to launch Americans back into space from U.S. soil — no plan to head back to the moon, no urgent strategy or timetable to head to Mars or even an asteroid — for the foreseeable future.

“That is not A-OK.  It’s unfortunate for a nation that led the way in space exploration and dominated science and technology with its innovation and inspiration.  The space program led to a generation of students inspired to pursue technology and science.  It helped lead to inventions like GPS in our cell phones, global satellite communications and medical imaging.  It spurred private industry and job growth, and the kind of discovery and inspiration so vitally needed now as American students try to catch up on science and math skills in an increasingly competitive and globalizing world.  Atlantis sped homeward on the 135th and final voyage of the 30-year space shuttle program.  When it returns to Earth, heaven can wait for now, it seems, or at least the final frontier and the future of manned spaceflight in America.  U.S. astronauts are stuck with only one near-term option, hitching expensive rides on Russian rockets, to get back to the space station.  Without a clear U.S. goal and a timetable to achieve it, many Americans worry about the future of the U.S. space program.  America is hardly at square one, but in the race for space, it has led the way, so this hiatus of five or 10 years, maybe more, is deeply troubling,” Rowley concluded.

The End of CO2?

Monday, June 14th, 2010

The end of CO2 emissions is getting closer.  The end may be in sight to phase out CO2-emitting coal by 2030, according to Architecture 2030 a non-profit, non-partisan and independent organization established in response to the global-warming crisis.  That conclusion comes from researchers at leading institutions such as NASA, NREL, Architecture 2030 and Columbia University.

The paper issued by the institutions – titled “Options for Near-Term Phaseout of CO2 Emissions from Coal Use in the United States” – will be published in the June edition of Environmental Science & Technology, the official publication of the American Chemical Society.  According to the article, “The only practical way to preserve a planet resembling that of the Holocene (i.e., the world as we know it)…is to rapidly phase out coal emissions.”

Architecture 2030 notes that “This sets up an immediate choice.  We can phase out coal CO2 emissions by 2030 and keep the planet we have or we can continue with ‘business as usual’ and hope for the best in one of the craziest games of risk the world has ever known.  Which ending will we choose?”

Architecture 2030 is advocating to phase out coal CO2 emissions by the target year because they think “the game of risk” isn’t worthwhile and because the United States already has all the tools it needs to achieve that goal.  “We don’t have to wait on ‘clean coal’ technology, technically known as carbon capture and sequestration (CSS), which is decades away and may not be proven economically or technologically feasible.  We can phase out coal emissions with existing know-how and off-the shelf technologies.”