New Results from a Terra-ific Decade in Orbit

December 18, 2009, marks the tenth year since the launch of Terra, one of NASA's "flagship" Earth observing satellites. But the decade is more than just a mechanical milestone. With each additional day and year that the satellite monitors Earth, scientists achieve a lengthened record of Earth's vital signs. It's that record that helps scientists assess the health of Earth's ocean, land, and atmosphere, and determine how these systems are changing.

"Earth system science is a relatively young science," said Marc Imhoff, project scientist for the mission and a researcher at NASA's Goddard Space Flight Center in Greenbelt, Md. "Terra's sensors have provided the first coordinated set of observations allowing us to link Earth system processes across space and time so we can better understand how they function together and how we interact with them."

Since Terra's five instruments officially saw "first light" on Feb 24, 2000, after a post-launch checkout, the data have continued to advance Earth system science. Here's a sample of the latest developments to be presented by Terra researchers at the Fall Meeting of the American Geophysical Union in San Francisco.

Droughts Slow Earth's Carbon Metabolism

Data from Terra's Moderate Resolution Imaging Spectroradiometer (MODIS) have turned up evidence that climate change may have negative effects for ecosystems earlier than we thought, according to Maosheng Zhao, an ecologist at the University of Montana in Missoula.

For the past several decades, photosynthesis by land plants and trees has absorbed, or acted as a "sink," for about one third of global carbon dioxide emissions, helping to slow the increase of the greenhouse gas in the atmosphere. But scientists have found that global carbon uptake by land plants is declining.

"This decreasing trend has very important implications for how much and how long humans should count on the carbon sink capacity of terrestrial ecosystems," Zhao said.

To arrive at their finding, Zhao and colleagues analyzed MODIS data from 2000 to 2008. Directly measuring carbon dioxide from space is difficult, so scientists rely on sensors to measure the photosynthetic activity of plants. That activity can then be translated to an estimate of how much carbon dioxide the plants are absorbing. "So far, MODIS is the best sensor we have for monitoring global vegetation dynamics," Zhao said.

A closer look reveals that carbon uptake is still on the rise in middle and high latitudes of the northern hemisphere. But that benefit is outweighed by changes in the tropics and southern hemisphere, where scientists observed less carbon being absorbed.

Zhao thinks that a major cause of the decrease is warming-related droughts, which impact crop yields, timber production, and expanses of natural vegetation.

Some computer models have predicted that by the middle of this century, carbon-climate feedbacks could cause terrestrial ecosystems to shift from being carbon sinks to sources, according to Zhao. "Our result is an early warning that we must take some actions to mitigate human-induced climate change."

Natural Hazards Tracked

There's no escaping the risk to human populations posed by natural hazards. But for almost 10 years, Terra has helped governments and local groups respond to and mitigate the consequences.

Just last month in El Salvador, Hurricane Ida brought heavy rains that triggered flooding and deadly mudslides. In another incident in November, a major algal bloom in Guatemala's Lake Atitlan had residents concerned about the lake's health and the safety of people who swim in and drink the water.

To help monitor these hazards, local governments and data processing groups turn to NASA for images from Terra's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER ). The instrument's spatial resolutions of about 15 to 90 meters produce detailed maps of land surface characteristics such as temperature, reflectance and elevation, which are key for helping decision-makers determine where and how to respond.

"The request for the mudslide and algal bloom images are typical of the types of requests we receive," said Michael Abrams, ASTER science team leader at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We also work with the U.S. Forest Service to image active wildfires for logistical support and often for post-fire damage assessment and mitigation."

Instrument operators can point ASTER -- an instrument provided by Japan's Ministry of Economy Trade and Industry -- at specific targets and acquire about 500 images per day. Each day about 3,000 requests are active in the request database, ranging from field work, global maps, and regional monitoring. To decide where to point the instrument, an algorithm was developed to automatically prioritize requests.

For example, immediate threats such as the requests from El Salvador's Civil Protection Agency to monitor the flooding and mudslides and Guatemala's Ministry of Agriculture to monitor the algal bloom, receive higher priority. Lower priority targets include a project to obtain complete global maps of ASTER imagery at least 3-5 times during mission.

As part of its monitoring of natural hazards, ASTER has been keeping a long-term eye on more than 1,000 active volcanoes around the world. The extended archive will be used by researchers to characterize the historical behavior for each volcano.

"To improve prediction, we need to know which signals are important," Abrams said.

Pollution Travels High and Far

The Station wildfire that burned southern California in late August 2009 was the largest fire in the recorded history of Los Angeles County and its Angeles National Forest, with more than 160,577 acres burned. Pollution created by the wildfire traveled even further. Rising more than 4 miles (7 kilometers) above Earth's surface, smoke from the fire was carried over Nevada, Utah, and Colorado, and carbon monoxide from the fire traveled at least as far as Louisiana.

The measurement of smoke height was possible with Terra's Multiangle Imaging SpectroRadiometer (MISR ), which can resolve atmospheric components -- such as, clouds, dust and smoke plumes -- in three dimensions. MISR can also measure horizontal winds.

Scientists have used the instrument to develop a multi-year "climatology" or statistical database of the heights to which wildfires inject smoke into the atmosphere. The database now contains observations from more than 7,000 smoke plumes in North America, Siberia, and Africa.

"We discovered that for about one-fifth of wildfires, the smoke particles escape the low, turbulent part of the atmosphere and rise to a higher altitude, where they can remain concentrated for long periods and also be transported great distances " said David Diner, MISR principal investigator at JPL.

Researchers studying the dispersal of particulates from wildfires, volcanoes, and dust storms also use the data to test theoretical simulations against observed behavior. These simulations will help researchers understand, for example, what the effect of more fires in a warmer climate might have on air quality.

Other scientists are watching pollution that travels even greater distances, across international boundaries. Measurements of carbon monoxide from the Measurements of Pollution in the Troposphere instrument MOPITT -- provided by the Canadian Space Agency -- and of aerosols from the MISR and MODIS instruments allow scientists to observe both the sources and transport of pollution on a global scale.

"The Terra satellite made it possible to track pollution plumes as they are transported across the ocean, allowing us to observe numerous plumes of Asian pollution transported to the United States," said Daniel Jacob, an atmospheric scientist at Harvard University in Cambridge, Mass. "The findings show that air pollution is a global issue, and thus that meeting air quality goals in the United States will increasingly require international cooperation."

Balancing the Energy Budget

As society considers carbon dioxide caps and geoengineering, open questions remain about exactly how, why, and where Earth is warming. Answering those questions requires a clear picture of how the Earth's energy budget is changing.

For a decade, researchers using the Clouds and the Earth's Radiant Energy System (CERES) experiment on Terra have been taking stock of how much solar energy is absorbed by the planet's atmosphere and surface, and how much infrared and heat energy is emitted back into space. CERES scientists also study how cloud properties influence the energy exchange from space to the atmosphere to the ground and back again.

"CERES has provided a decade of accurate observations that allow us to explore changes over time, to see how radiation at the top of the atmosphere varies seasonally and annually," said Kevin Trenberth, A CERES investigator from the National Center for Atmospheric Research in Boulder, Colo. "The longer the record, the more valuable it becomes."

The observations have shown that the world is cloudier than we thought, and changes in cloudiness can lead to regional and global fluctuations in the heat budget. For instance, albedo is decreasing in the Arctic as snow and sea ice melt, but there is also evidence of compensation from an increase in cloud cover.

Researchers including Norman Loeb of NASA's Langley Research Center, Hampton, Va., and principal investigator for the CERES instrument, have found that measurements of the energy budget from space correlate well with what is being observed by heat content observations in the ocean, where most solar heat retained by Earth is stored.

Most strikingly, the CERES science team has updated the numbers in the planetary budget ledger and found a gap between incoming and outgoing radiation. The Earth is estimated to be absorbing at a rate of about 0.9 Watts per square meter more than it is emitting -- large enough to provoke the question: what does it mean for climate change?

"Terra has allowed us to observe cloud heights with MISR; cloud density and coverage, with MODIS, as well as sea ice, glaciers and surface temperatures; and incoming and outgoing radiation with CERES," said Marc Imhoff, project scientist for Terra. "That's a very powerful combo for understanding how the atmosphere, land, and oceans work together in balancing heat."

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Solar Storms and Radiation Exposure on Commercial Flights

Scientists at NASA’s Langley Research Center have completed a first attempt to accurately calculate the level of damaging radiation flight crews and passengers are exposed to on commercial airline flights. The work is an early step toward developing a model to observe radiation exposure for all commercial flights, particularly for pilots and crews who spend their careers airborne and who are at greater risk of developing certain cancers.

The study considered not only everyday radiation emanating from space, but also the additional energy unleashed during a solar storm, which can be profound. NASA scientists say not including geomagnetic effects on solar radiation in modeling radiation exposure could underestimate the dosage by 30 to 300 percent.

Researchers looked at passengers and crew on typical flights from Chicago to Beijing, Chicago to Stockholm and London to New York, during what is known as the Halloween 2003 Storm. These flights were chosen because of their long flight paths near the North Pole, where the Earth’s natural protection from radiation is weakest. Earth’s magnetic field approaches zero above the poles. The Halloween 2003 event was chosen because it was both a large and a complex storm, making it a good test for the model.

The study found that aircrew and passengers during the Chicago to Beijing flight, for example, would have been exposed to about 12 percent of the annual radiation limit recommended by the International Committee on Radiological Protection. But these exposures were greater than on typical flights at lower latitudes, and confirmed the concerns about commercial flights at high latitudes.

“The upshot is that these international flights were right there at that boundary where many of these events can take place, where radiation exposure can be much higher,” said Chris Mertens, senior research scientist at NASA’s Langley Research Center, who is leading the research effort. Mertens will present his latest results at the American Geophysical Union fall meeting in San Francisco on Dec. 16.

Piecing together the radiation exposure on these typical flights is the first step toward developing a real-time system that researchers hope will become a standard component of commercial airline cockpits. Radiation exposure could one day be taken into account in the same way weather conditions are considered before deciding to fly or deciding what exact route to fly and at what altitude.


Flying above and beyond Earth’s natural protection

The number of international flights that skirt the north pole are increasing. Airlines save massive amounts of fuel on flights such as Chicago-to-Shanghai by simply flying “over the top” – it is a far shorter route than following the latitude lines. But while saving fuel, these flight paths take planes and their passengers to the thinner layers of Earth’s magnetosphere, which shields potentially harmful solar and cosmic radiation.

On a typical day, the Sun is quiet and “background radiation,” the cumulative effect of radiation from cosmic sources reaching Earth, is the only other source. But when the Sun is not quiet, violent storms on the star’s surface eject powerful bursts of radiation to the Earth. It is these events that have never been truly accounted for in studies of how much radiation pilots and airline passengers are exposed to.


Pilots Await Results

While the flights studied appear to have not put passengers in danger of exceeding the safe radiation limit in an individual flight, concerns remain, Mertens said. Many workers whose jobs expose them to consistent radiation sources log that exposure to keep a record over one’s career. People who work on commercial airline flights are technically listed as “radiation workers” by the federal government – a classification that includes nuclear plant workers and X-ray technicians. But unlike some others in that category, flight crews do not quantify the radiation they are exposed to.

Mike Holland, an American Airlines captain and vice chairman for radiation and environmental issues with the Allied Pilots Association, said he is following Mertens’ research with interest. The pilots association has written a formal letter in support of the research. Holland cited studies that show pilots face a four-times greater risk of melanoma than the general population. But because pilots and flight crews do not wear radiation-measuring badges like other radiation workers, the only estimates about their career-long exposure come from models.

Up until now, most of those models only attempted to capture the amount of cosmic background radiation that reaches airliners in flight. Holland said he believes including solar radiation, especially during solar storms, is important. He looks forward to having answers for the pilots who contact him with questions about radiation and cancer risk.

“When I talk to epidemiologists, they have two questions for me: What is your exposure? And what is your health for 20 to 30 years after you retire?” Holland said. The second question he and other pilots can answer, in time. But as of now, they can’t measure their exposure.

“We’re excited that Chris is doing this,” Holland said, “and we hope it can answer the epidemiologists first question, which is, ‘What is your exposure?’”

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NASA Outlines Recent Greenhouse Gas Research

Researchers studying carbon dioxide, a leading greenhouse gas and a key driver of global climate change, now have a new tool at their disposal: daily global measurements of carbon dioxide in a key part of our atmosphere. The data are courtesy of the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft.

Moustafa Chahine, the instrument's science team leader at NASA's Jet Propulsion Laboratory, Pasadena, Calif., unveiled the new product at a briefing on recent breakthroughs in greenhouse gas, weather and climate research from AIRS at this week's American Geophysical Union meeting in San Francisco. The new data have been extensively validated against both aircraft and ground-based observations. They give users daily and monthly measurements of the concentration and distribution of carbon dioxide in the mid-troposphere--the region of the atmosphere located between 5 and 12 kilometers, or 3 to 7 miles, above Earth's surface, and track its global transport. Users can also access historical AIRS carbon dioxide data spanning the mission's entire seven-plus years in orbit. The product represents the first-ever release of global daily carbon dioxide data that are based solely on observations.

"AIRS provides the highest accuracy and yield of any global carbon dioxide data set available to the research community, now and for the immediate future," said Chahine. "It will help researchers understand how this elusive, long-lived greenhouse gas is distributed and transported, and can be used to develop better models to identify 'sinks,' regions of the Earth system that store carbon dioxide. It's important to study carbon dioxide in all levels of the troposphere."

Chahine said previous AIRS research data have led to some key findings about mid-tropospheric carbon dioxide. For example, the data have shown that, contrary to prior assumptions, carbon dioxide is not well mixed in the troposphere, but is rather "lumpy." Until now, models of carbon dioxide transport have assumed its distribution was uniform.

Carbon dioxide is transported in the mid-troposphere from its sources to its eventual sinks. More carbon dioxide is emitted in the heavily populated northern hemisphere than in its less populated southern counterpart. As a result, the southern hemisphere is a net recipient, or sink, for carbon dioxide from the north. AIRS data have previously shown the complexity of the southern hemisphere's carbon dioxide cycle, revealing a never-before-seen belt of carbon dioxide that circles the globe and is not reflected in transport models.

In another major finding, scientists using AIRS data have removed most of the uncertainty about the role of water vapor in atmospheric models. The data are the strongest observational evidence to date for how water vapor responds to a warming climate.

"AIRS temperature and water vapor observations have corroborated climate model predictions that the warming of our climate produced as carbon dioxide levels rise will be greatly exacerbated -- in fact, more than doubled -- by water vapor," said Andrew Dessler, a climate scientist at Texas A&M University, College Station, Texas.

Dessler explained that most of the warming caused by carbon dioxide does not come directly from carbon dioxide, but from effects known as feedbacks. Water vapor is a particularly important feedback. As the climate warms, the atmosphere becomes more humid. Since water is a greenhouse gas, it serves as a powerful positive feedback to the climate system, amplifying the initial warming. AIRS measurements of water vapor reveal that water greatly amplifies warming caused by increased levels of carbon dioxide. Comparisons of AIRS data with models and re-analyses are in excellent agreement.

"The implication of these studies is that, should greenhouse gas emissions continue on their current course of increase, we are virtually certain to see Earth's climate warm by several degrees Celsius in the next century, unless some strong negative feedback mechanism emerges elsewhere in Earth's climate system," Dessler said.

Originally designed to observe atmospheric temperature and water vapor, AIRS data are already responsible for the greatest improvement to five- to six-day weather forecasts than any other single instrument, said Chahine. JPL scientists have shown a major consequence of global warming will be an increase in the frequency and strength of severe storms. Earlier this year, a team of NASA researchers showed how AIRS can significantly improve tropical cyclone forecasting. The researchers studied deadly Typhoon Nargis in Burma in May 2008. They found the uncertainty in the cyclone's landfall position could have been reduced by a factor of six had more sophisticated AIRS temperature data been used in the forecasts.

AIRS observes and records the global daily distribution of temperature, water vapor, clouds and several atmospheric gases including ozone, methane and carbon monoxide. With the addition of the mid-tropospheric carbon dioxide data set this week, a seven-year digital record is now complete for use by the scientific community and the public.

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The Dark Side of Carbon

As interest in Earth's changing climate heats up, a tiny dark particle is stepping into the limelight: black carbon. Commonly known as soot, black carbon enters the air when fossil fuels and biofuels, such as coal, wood, and diesel are burned. Black carbon is found worldwide, but its presence and impact are particularly strong in Asia.

Black carbon, a short-lived particle, is in perpetual motion across the globe. The Tibetan Plateau's high levels of black carbon likely impact the region's temperature, clouds and monsoon season.

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Preparing for Lift

At NASA's Kennedy Space Center in Florida, workers prepare to attach a lifting sling on space shuttle Endeavour following its arrival in the Vehicle Assembly Building transfer aisle.

Endeavour was towed from the nearby Orbiter Processing Facility in preparation for launch of the STS-130 mission.

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Preps for the STS-130 Mission Continue

Technicians at NASA's Kennedy Space Center in Florida are testing the electrical connections on space shuttle Endeavour in the Vehicle Assembly Building.

The vehicle and its solid rocket boosters will be powered-up for the shuttle interface test and the twin boosters hydraulic systems will be tested for leaks today.

Meanwhile, at NASA's Johnson Space Center in Houston, the six STS-130 mission astronauts will conduct a deorbit preparation simulation attired in their orange launch-and-landing suits.

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Lifting Off to Study the Sky

NASA's Wide-field Infrared Survey Explorer, or WISE, launched aboard a United Launch Alliance Delta II rocket at 9:09 a.m. EST from Space Launch Complex-2 at Vandenberg Air Force Base. WISE will scan the entire sky in infrared light, picking up the glow of hundreds of millions of objects and producing millions of images.

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NASA Looks for Safer Icing Forecast For Pilots

Of the many dangers that plague commercial airplanes, icing stands out as one of the most treacherous. The threat of ice build-up on aircraft surfaces has been known and studied for decades, but now NASA is putting new effort into understanding a different kind of ice danger.

A well-known icing problem involves ice forming on wings and other surfaces that can cause drag and power loss on an aircraft. A different threat emerges when airplanes fly into clouds with high ice content found near thunderstorms in very high altitudes. Ice particles, once thought benign because they would simply bounce of airplane surfaces, can accrete deep inside jet engines and shut down the power. This is called “ice particle icing,” to distinguish it from icing caused by super-cooled liquid droplets, which typically occurs at lower altitudes.

There have been more than 240 icing-related incidents in commercial aviation since the 1990s, of which 62 resulted in power-loss likely due to ice particle icing, according to a study authored by Jeanne G. Mason, J. Walter Strapp and Phillip Chow. This condition is difficult for pilots to identify because in many cases the ice is forming only inside the engine, without any visible icing on the wings.

Researchers at NASA’s Langley Research Center are taking a closer look at the phenomenon, which is considered a significant threat to commercial airlines. NASA scientists are developing ways to identify the conditions that cause ice particle icing to better warn pilots about where this might occur.

“It’s something that hasn’t been explored much,” said Chris Yost, a NASA contractor and research scientist with Science Systems and Applications Inc. in Hampton, Va. Yost said his research is at a preliminary stage now, focused on pinpointing the types of clouds connected with ice particle icing. He will present his latest results at the American Geophysical Union fall meeting in San Francisco on Dec. 14.

“These are deep convection, thunderstorm-like clouds,” Yost said. “Thin, wispy cirrus stuff is not so much a problem.”

NASA research is aiming to improve weather forecasts that could steer pilots away from trouble. Building on tools developed to detect surface icing conditions, NASA scientists are using cloud observations from two satellites, CALIPSO and CloudSat.

CALIPSO and CloudSat fly only seconds apart on the same orbit. Together they provide never-before-seen 3-D perspectives of how clouds and aerosols form, evolve, and affect weather and climate. In preliminary research, CloudSat and CALIPSO have been used to build on previous methods of identifying the type of moisture particles that lead to ice particle icing problems. CALIPSO’s lidar is used to create a vertical profile of clouds to accurately measure cloud height while CloudSat provides the estimates of ice concentration in those clouds. Together the two instruments provide very detailed information about the vertical structure of clouds, and the ice particles within them.

Yost and other SSAI researchers have been working with Patrick Minnis, at NASA’s Langley Research Center, on incorporating CALIPSO and CloudSat data into forecast models with the goal of identifying potential ice particle icing conditions.

NASA’s research on ice particle icing began in 2005 with the integration of cloud data from the NOAA satellite GOES. This was followed on by a field experiment on NASA’s DC-8 in 2007 to compare ice particle measurements from GOES with actual aircraft measurements. While this data significantly increased researchers understanding of the icing process, the integration of CALIPSO and CloudSat data has vastly enhanced the ability to see what is within the clouds.

Yost is currently comparing satellite records of weather conditions with the coordinates and time and date of specific airplane power-loss incidents in recent years. The research could illuminate more specifically what type of weather leads to ice particle icing and whether ice particle icing was a factor in these accidents. Future plans include flights with NASA’s DC-8 to take on-board measurements as a comparison point for CALIPSO and CloudSat observations.

Minnis described the group’s ongoing work as a first cut, but envisions it leading to better forecasting of potential ice particle icing conditions in the future.

“The ultimate goal of the project is to be integrated into existing forecast models and eventually into the NextGen (Next Generation Air Transportation System) cockpit system,” Minnis said.

Aviation safety organizations around the world are presently working with the ultimate goal of being able to accurately forecast inflight icing conditions in real-time for pilots. The integration of NASA satellite data into forecasting models is bringing them closer than to that goal, step by step.

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Global Digital Elevation Model

This Global Digital Elevation Model, or GDEM, is a product of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), a joint program of NASA and Japan's Ministry of Economy, Trade and Industry. The image was released on June 29, 2009, and was created by processing and stereo-correlating the 1.3 million-scene ASTER archive of optical images, covering Earth's land surface between 83 degrees North and 83 degrees South latitudes. The GDEM is produced with 98-feet postings, and is formatted as 23,000 one-by-one-degree tiles. In this colorized version, low elevations are purple, medium elevations are greens and yellows, and high elevations are orange, red and white.

With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of 50 to 300 feet, ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on NASA's Terra satellite.

The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping and monitoring of dynamic conditions and temporal change.

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NASA Data Reveal Major Groundwater Loss in California's Heartland

New space observations reveal that since October 2003, the aquifers for California's primary agricultural region -- the Central Valley -- and its major mountain water source -- the Sierra Nevadas -- have lost nearly enough water combined to fill Lake Mead, America's largest reservoir. The findings, based on data from the NASA/German Aerospace Center Gravity Recovery and Climate Experiment (Grace), reflect California's extended drought and increased rates of groundwater being pumped for human uses, such as irrigation.

In research being presented this week at the American Geophysical Union meeting in San Francisco, scientists from NASA and the University of California, Irvine, detailed California's groundwater changes and outlined Grace-based research on other global aquifers. The twin Grace satellites monitor tiny month-to-month changes in Earth's gravity field primarily caused by the movement of water in Earth's land, ocean, ice and atmosphere reservoirs. Grace's ability to directly 'weigh' changes in water content provides new insights into how Earth's water cycle may be changing.

Combined, California's Sacramento and San Joaquin drainage basins have shed more than 30 cubic kilometers of water since late 2003, said professor Jay Famiglietti of the University of California, Irvine. A cubic kilometer is about 264.2 billion gallons, enough to fill 400,000 Olympic-size pools. The bulk of the loss occurred in California's agricultural Central Valley. The Central Valley receives its irrigation from a combination of groundwater pumped from wells and surface water diverted from elsewhere.

"Grace data reveal groundwater in these basins is being pumped for irrigation at rates that are not sustainable if current trends continue," Famiglietti said. "This is leading to declining water tables, water shortages, decreasing crop sizes and continued land subsidence. The findings have major implications for the U.S. economy, as California's Central Valley is home to one sixth of all U.S. irrigated land, and the state leads the nation in agricultural production and exports."

"By providing data on large-scale groundwater depletion rates, Grace can help California water managers make informed decisions about allocating water resources," said Grace Project Scientist Michael Watkins of NASA's Jet Propulsion Laboratory, Pasadena, Calif., which manages the mission for NASA's Science Mission Directorate, Washington.

Preliminary studies show most of the water loss is coming from the more southerly located San Joaquin basin, which gets less precipitation than the Sacramento River basin farther north. Initial results suggest the Sacramento River basin is losing about 2 cubic kilometers of water a year. Surface water losses account for half of this, while groundwater losses in the northern Central Valley add another 0.6 cubic kilometers annually. The San Joaquin Basin is losing 3.5 cubic kilometers a year. Of this, more than 75 percent is the result of groundwater pumping in the southern Central Valley, primarily to irrigate crops.

Famiglietti said recent California legislation decreasing the allocation of surface waters to the San Joaquin Basin is likely to further increase the region's reliance on groundwater for irrigation. "This suggests the decreasing groundwater storage trends seen by Grace will continue for the foreseeable future," he said.

The California results come just months after a team of hydrologists led by Matt Rodell of NASA's Goddard Space Flight Center, Greenbelt, Md., found groundwater levels in northwest India have declined by 17.7 cubic kilometers per year over the past decade, a loss due almost entirely to pumping and consumption of groundwater by humans.

"California and India are just two of many regions around the world where Grace data are being used to study droughts, which can have devastating impacts on societies and cost the U.S. economy $6 to $8 billion annually," said Rodell. Other regions under study include Australia, the Middle East – North Africa region and the southeastern United States, where Grace clearly captured the evolution of an extended drought that ended this spring. In the Middle East – North Africa region, Rodell is leading an effort to use Grace and other data to systematically map water- and weather-related variables to help assess regional water resources. Rodell added Grace may also help predict droughts, since it can identify pre-existing conditions favorable to the start of a drought, such as a deficit of water deep below the ground.

NASA is working with the National Oceanic and Atmospheric Administration and the University of Nebraska-Lincoln to incorporate Grace data into NOAA's U.S. and North American Drought Monitors, premier tools used to minimize drought impacts. The tools rely heavily on precipitation observations, but are limited by inadequate large-scale observations of soil moisture and groundwater levels. "Grace is the only satellite system that provides information on these deeper stores of water that are key indicators of long-term drought," Rodell said.

Grace is a partnership of NASA and the German Aerospace Center (DLR). The University of Texas Center for Space Research, Austin, has overall mission responsibility. JPL developed the satellites. DLR provided the launch, and GeoForschungsZentrum Potsdam, Germany, operates the mission. For more on Grace, see http://www.csr.utexas.edu/grace/ and http://grace.jpl.nasa.gov/ . Other media contacts: Margaret Baguio, University of Texas Center for Space Research, 512-471-6922; Jennifer Fitzenberger, University of California, Irvine, 949-824-3969.

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New Study Turns Up the Heat on Soot's Role in Himalayan Warming

Soot from fire in an unventilated fireplace wafts into a home and settles on the surfaces of floors and furniture. But with a quick fix to the chimney flue and some dusting, it bears no impact on a home’s long-term environment.

A new modeling study from NASA confirms that when tiny air pollution particles we commonly call soot – also known as black carbon – travel along wind currents from densely populated south Asian cities and accumulate over a climate hotspot called the Tibetan Plateau, the result may be anything but inconsequential.

In fact, the new research, by NASA’s William Lau and collaborators, reinforces with detailed numerical analysis what earlier studies suggest: that soot and dust contribute as much (or more) to atmospheric warming in the Himalayas as greenhouse gases. This warming fuels the melting of glaciers and could threaten fresh water resources in a region that is home to more than a billion people.

Lau explored the causes of rapid melting, which occurs primarily in the western Tibetan Plateau, beginning each year in April and extending through early fall. The brisk melting coincides with the time when concentrations of aerosols like soot and dust transported from places like India and Nepal are most dense in the atmosphere.

"Over areas of the Himalayas, the rate of warming is more than five times faster than warming globally," said William Lau, head of atmospheric sciences at NASA’s Goddard Space Flight Center in Greenbelt, Md. "Based on the differences it’s not difficult to conclude that greenhouse gases are not the sole agents of change in this region. There’s a localized phenomenon at play."

Nicknamed the “Third Pole”, the region in fact holds the third largest amount of stored water on the planet beyond the North and South Poles. But since the early 1960s, the acreage covered by Himalayan glaciers has declined by over 20 percent. Some Himalayan glaciers are melting so rapidly, some scientists postulate, that they may vanish by mid-century if trends persist. Climatologists have generally blamed the build-up of greenhouse gases for the retreat, but Lau’s work suggests that may not be the complete story.

He has produced new evidence suggesting that an “elevated heat pump” process is fueling the loss of ice, driven by airborne dust and soot particles absorbing the sun’s heat and warming the local atmosphere and land surface. A related modeling study by Lau and colleagues has been submitted to Environmental Research Letters for publication.

A unique landscape plays supporting actor in the melting drama. The Himalayas, which dominate the plateau region, are the source of meltwater for many of Asia’s most important rivers—the Ganges and Indus in India, the Brahmaputra in Bangladesh, the Salween through China, Thailand and Burma, the Mekong across Laos, Cambodia and Vietnam, and the Yellow and Yangtze rivers in China. When fossil fuels are burned without enough oxygen to complete combustion, one of the byproducts is black carbon, an aerosol that absorbs solar radiation (Most classes of aerosols typically reflect incoming sunlight, causing a cooling effect). Rising populations in Asia, industrial and agricultural burning, and vehicle exhaust have thickened concentrations of black carbon in the air.

Sooty black carbon travels east along wind currents latched to dust – its agent of transport – and become trapped in the air against Himalayan foothills. The particles’ dark color absorbs solar radiation, creating a layer of warm air from the surface that rises to higher altitudes above the mountain ranges to become a major catalyst of glacier and snow melt.

Building on work by Veerabhardran Ramanathan of the Scripps Institution of Oceanography, San Diego, Calif., Lau and colleagues conducted modeling experiments that simulated the movement of air masses in the region from 2000 to 2007. They also made detailed numerical analyses of how soot particles and other aerosols absorb heat from the sun.

"Field campaigns with ground observations are already underway with more planned to test Lau’s modeling results," said Hal Maring who manages the Radiation Sciences program at NASA Headquarters in Washington. "But even at this stage we should be compelled to take notice."

“Airborne particles have a much shorter atmospheric lifespan than greenhouse gases,” continued Maring. “So reducing particle emissions can have much more rapid impact on warming.”

"The science suggests that we’ve got to better monitor the flue on our 'rooftop to the world," said Lau. "We need to add another topic to the climate dialogue."

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A Unique Geography -- and Soot and Dust -- Conspire Against Himalayan Glaciers

"So many disparate elements, both natural and man-made, converge in the Himalayas," said William Lau, a climatologist from NASA’s Goddard Space Flight Center in Greenbelt, Md. "There’s no other place in the world that could produce such a powerful atmospheric heat pump," referring to a new hypothesis he’s put forward to explain the rapid retreat of Himalayan glaciers in recent decades.

The Himalayas, home to the tallest mountains on Earth, include more than 110 peaks and stretch 2,500 kilometers (1,550 miles). Bounded to the north by the Tibetan Plateau, to the west by deserts, and to the south by a bowl-like basin teeming with people, the mountains hold 10,000 glaciers.

These massive rivers of ice spill off mountain sides and grind down through creviced valleys. In the spring, when the monsoon carries moist air from the Indian Ocean, the glaciers begin to thaw, replenishing lakes, streams, and some of Asia's mightiest rivers, on which more than a billion people depend.

South of the Himalayas -- which forms the east-west edge of the table-like Tibetan Plateau -- the mountains give way to the Indo-Gangetic plain, one of the most fertile and densely populated areas on Earth. The plain has become a megalopolis of cities including Delhi, Dhaka, Kanpur, and Karachi, as well as a hotspot for air pollution, with a steady supply of industrial soot mixing with ash and other particles in the air.

To the west, in the northwestern part of the Indian subcontinent, the Thar Desert stretches across 200,000 square kilometers (77,000 square miles) of arid, dusty land. During the spring, westerly winds pluck dust and sand from the Thar and blow it toward the Indo-Gangetic plain.

The dust joins a mash of industrial pollutants to create a massive brown cloud visible from space. Underneath the brown cloud, some solar radiation is blocked from reaching the surface, causing the under-lying land surface to cool.

"Surprisingly, these brown aerosol clouds seem to have potent climate consequences that affect the entire region," Lau said.

The thick soot and dust layer absorbs solar radiation, and heats up the air around the Himalayan foothills. The warm, rising air enhances the seasonal northward flow of humid monsoon winds, forcing moisture and hot air up the slopes of the Himalayas.

As the aerosol particles rise on the warm, convecting air, they produce more rain over northern India and the Himalayan foothill, which further warms the atmosphere and fuels a "heat pump" that draws yet more warm air to the region.

"The phenomenon changes the timing and intensity of the monsoon, effectively transferring heat from the low-lying lands over the subcontinent to the atmosphere over the Tibetan Plateau, which in turn warms the high-altitude land surface and hastens glacial retreat," Lau said. His modeling shows that aerosols -- particularly black carbon and dust -- likely cause as much of the glacial retreat in the region as greenhouse gases via this "heat pump" effect.

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Endeavour Awaits Move to Pad

At NASA's Kennedy Space Center in Florida, space shuttle Endeavour now is attached to its twin solid rocket boosters and external fuel tank atop the mobile launcher platform.

Rollout from the Vehicle Assembly Building to Launch Pad 39A is slated for early January 2010.

The six STS-130 astronauts are practicing with some of the tools they'll be using on their spacewalks in addition to rehearsing thermal protection system repair techniques at NASA's Johnson Space Center in Houston.

Shuttle Endeavour, with its payload of the Tranquility node and the seven-windowed Cupola module, is targeted to launch Feb. 4, 2010.

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NASA's WISE Eye on the Universe Begins All-Sky Survey Mission

NASA's Wide-field Infrared Survey Explorer, or WISE, lifted off over the Pacific Ocean this morning on its way to map the entire sky in infrared light.

A Delta II rocket carrying the spacecraft launched at 6:09 a.m. PST (9:09 a.m. EST) from Vandenberg Air Force Base in California. The rocket deposited WISE into a polar orbit 326 miles above Earth.

"WISE thundered overhead, lighting up the pre-dawn skies," said William Irace, the mission's project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "All systems are looking good, and we are on our way to seeing the entire infrared sky better than ever before."

Engineers acquired a signal from the spacecraft via NASA's Tracking and Data Relay Satellite System just 10 seconds after the spacecraft separated from the rocket. Approximately three minutes later, WISE re-oriented itself with its solar panels facing the sun to generate its own power. The next major event occurred about 17 minutes later. Valves on the cryostat, a chamber of super-cold hydrogen ice that cools the WISE instrument, opened. Because the instrument sees the infrared, or heat, signatures of objects, it must be kept at chilly temperatures. Its coldest detectors are less than minus 447 degrees Fahrenheit.

"WISE needs to be colder than the objects it's observing," said Ned Wright of UCLA, the mission's principal investigator. "Now we're ready to see the infrared glow from hundreds of thousands of asteroids, and hundreds of millions of stars and galaxies."

With the spacecraft stable, cold and communicating with mission controllers at JPL, a month-long checkout and calibration is underway.

WISE will see the infrared colors of the whole sky with sensitivity and resolution far better than the last infrared sky survey, performed 26 years ago. The space telescope will spend nine months scanning the sky once, then one-half the sky a second time. The primary mission will end when WISE's frozen hydrogen runs out, about 10 months after launch.

Just about everything in the universe glows in infrared, which means the mission will catalog a variety of astronomical targets. Near-Earth asteroids, stars, planet-forming disks and distant galaxies all will be easy for the mission to see. Hundreds of millions of objects will populate the WISE atlas, providing astronomers and other space missions, such as NASA's planned James Webb Space Telescope, with a long-lasting infrared roadmap.

JPL manages the Wide-field Infrared Survey Explorer for NASA's Science Mission Directorate in Washington. The mission was competitively selected under the Explorers Program, managed by NASA's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. NASA's Launch Services Program at NASA's Kennedy Space Center, Fla., managed the payload integration and the launch service.

More information about the WISE mission is available online at: http://www.nasa.gov/wise, http://wise.astro.ucla.edu and http://www.jpl.nasa.gov/wise.

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Now Online: Aeronautics Goes E-Book

E-book readers are expected to be among the hottest holiday gifts this year and their growing popularity has stirred NASA to begin reformatting its most popular aviation books to be compatible with the digital devices.

Available on the NASA aeronautics research Web site, the e-books can be downloaded at no charge for use with the Kindle™, SONY® Reader and, eventually, the nook™. Other formats for those without an e-book reader will be available as well.

The first NASA book to be made available is X-15: Extending the Frontiers of Flight by Dennis R. Jenkins. The book tells the story of the pioneering rocketplane that tested the limits of aviation during the 1960s and directly influenced the design and operation of the space shuttle.

"NASA's contributions to aviation affect everyone who has ever stepped foot inside an airplane. Now anyone can read about this historic aeronautical research with the convenience of a hand-held device," said Jaiwon Shin, associate administrator for NASA's Aeronautics Research Mission Directorate.

Next up on the list of books offered is Apollo of Aeronautics: NASA's Aircraft Energy Efficiency Program, 1973-1987 by Mark D. Bowles. This award-winning publication details the innovative research to improve aircraft and jet engine design in order to reduce fuel consumption by 50 percent.

And even as all archived NASA aeronautics books are being reformatted for use with the various e-book readers, plans are set for all future government-published books covering NASA's aeronautics research to be made available in e-book format.

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Freezing WISE's Hydrogen

A scaffolding structure built around NASA's Wide-field Infrared Survey Explorer, or WISE, allows engineers to freeze its hydrogen coolant. The WISE infrared instrument is kept extremely cold by a bottle-like tank filled with frozen hydrogen, called the cryostat. The cryostat can be seen at the top of the spacecraft.

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NASA's WISE Eye on the Universe Begins All-Sky Survey Mission

NASA's Wide-field Infrared Survey Explorer, or WISE, lifted off over the Pacific Ocean this morning on its way to map the entire sky in infrared light.

A Delta II rocket carrying the spacecraft launched at 9:09 a.m. EST from Vandenberg Air Force Base in California. The rocket deposited WISE into a polar orbit 326 miles above Earth.

"WISE thundered overhead, lighting up the pre-dawn skies," said William Irace, the mission's project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "All systems are looking good, and we are on our way to seeing the entire infrared sky better than ever before."

Engineers acquired a signal from the spacecraft via NASA's Tracking and Data Relay Satellite System just 10 seconds after the spacecraft separated from the rocket. Approximately three minutes later, WISE re-oriented itself with its solar panels facing the sun to generate its own power. The next major event occurred about 17 minutes later. Valves on the cryostat, a chamber of super-cold hydrogen ice that cools the WISE instrument, opened. Because the instrument sees the infrared, or heat, signatures of objects, it must be kept at chilly temperatures -- its coldest detectors are less than minus 447 degrees Fahrenheit.

"WISE needs to be colder than the objects it's observing," said Ned Wright of UCLA, the mission's principal investigator. "Now we're ready to see the infrared glow from hundreds of thousands of asteroids, and hundreds of millions of stars and galaxies."

With the spacecraft stable, cold and communicating with mission controllers at JPL, a month-long checkout and calibration is underway.

WISE will see the infrared colors of the whole sky with sensitivity and resolution far better than the last infrared sky survey, performed 26 years ago. The space telescope will spend nine months scanning the sky once, then one-half the sky a second time. The primary mission will end when WISE's frozen hydrogen runs out, about 10 months after launch.

Just about everything in the universe glows in infrared, which means the mission will catalog a variety of astronomical targets. Near-Earth asteroids, stars, planet-forming disks and distant galaxies all will be easy for the mission to see. Hundreds of millions of objects will populate the WISE atlas, providing astronomers and other space missions, such as NASA's planned James Webb Space Telescope, with a long-lasting infrared roadmap.

JPL manages the Wide-field Infrared Survey Explorer for NASA's Science Mission Directorate in Washington. The mission was competitively selected under the Explorers Program, managed by NASA's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. NASA's Launch Services Program at NASA's Kennedy Space Center, Fla., managed the payload integration and the launch service.

More information about the WISE mission is available online at:

http://www.nasa.gov/wise

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Challenges of Living and Working Aboard the Space Station: NASA Astronaut Nicole Stott Available for TV Interviews

After three months living aboard the International Space Station, NASA astronaut Nicole Stott will be available for satellite interviews from Houston between 6 a.m. and 7:45 a.m. CST on Thursday, Dec. 17.

To arrange an interview via NASA Television, journalists should contact Derek Sollosi at 281-792-7515 or by e-mail to derek.sollosi-1@nasa.gov by 1 p.m. on Wednesday, Dec. 16. B-roll of Stott's flight will air from 5:30 a.m. to 6 a.m. Dec. 17.

Stott, of Clearwater, Fla., served as a flight engineer for Expeditions 20 and 21 aboard the station and joined five other crew members living on the orbiting complex. She was the chief robotics operator, responsible for capturing, berthing and later releasing the first Japanese cargo ship flown to the station. In addition to working on multiple scientific studies, she also conducted a 6-and-a-half-hour spacewalk in September to continue station assembly.

Stott was the final station resident to fly to and from the complex on the space shuttle. She launched on space shuttle Discovery in August and returned to Earth aboard shuttle Atlantis in November. Stott spent a total of 91 days in space, 87 of them aboard the station. Stott has been assigned to fly on the STS-133 mission in September 2010, currently the final scheduled flight of the Space Shuttle Program.

The NASA Live Interview Media Outlet channel will be used for the interviews. The channel is a digital satellite C-band downlink by uplink provider Americom. It is on satellite AMC 6, transponder 5C, located at 72 degrees west, downlink frequency 3785.5 Mhz based on a standard C-band 5150 Mhz L.O., vertical polarity, FEC is 3/4, data rate is 6.00 Mhz, symbol rate is 4.3404 Mbaud, transmission DVB, minimum Eb/N0 is 6.0 dB.

The interviews also will be broadcast live on NASA TV. For streaming video, downlink and scheduling information, visit:

http://www.nasa.gov/ntv

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Tropical Cyclone 05B Forms Southeast of Chennai, India

Tropical Cyclone 05B has formed out of "System 96B" in the Northern Indian Ocean and is forecast to approach southeastern India by Sunday, December 13 and make landfall on Monday.

On Friday, December 11 at 15:00 UTC (10 a.m. ET or 8 p.m. local Asia/ Kolkata time in Chennai, India), Tropical Storm 05B had maximum sustained winds near 40 mph. It was located about 370 nautical miles southeast of Chennai, India, near 9.3 North latitude and 85.1 East longitude. It was moving north-northeast near 7mph, but is expected to gradually turn west and head for landfall.

Today, the Tropical Storm 05B is in an area of low wind shear, so it can continue to intensify. The only thing currently in 05B's path is a strong zonal jet stream over central India, but forecasters expect that to lift north in the next two days, and that means 05B can strengthen. Tropical Storm 05B is projected to turn west in the Bay of Bengal and make landfall in the state of Tamil Nadu by December 14.

The Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite captured Tropical Storm 05B on Dec. 10 southeast of the Indian state of Tamil Nadu. Infrared imagery shows temperatures and the colder the cloud tops of thunderstorms in a tropical cyclone are the higher they are, and the stronger they are. The imagery from AIRS indicated some strong thunderstorms in Tropical Storm 05B.

Residents along the coast of southeastern India in the Tamil Nadu state should make preparations. Some cities that may be affected by heavy rains and gusty winds include: Chennai, Thanjavur, Mahabalipuram, Chengalpattu, Maraimalai Nagar, Mudichur, Madhurantakam and others in that region.

The Joint Typhoon Warning Center forecasts Tropical Storm 05B to make landfall south of Chennai before 12:00 UTC or 5 p.m. local Asia/Kolkata time on Monday, December 14.

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Endeavour on the Move Today

Space shuttle Endeavour is ready to leave its hangar and be transported to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. Rollover is a major milestone to get a shuttle ready for its next mission.

Managers are meeting this morning to confirm everything is on track for Endeavour's move from Orbiter Processing Facility-2 to the VAB starting at 1 p.m. EST.

NASA TV will air live video coverage of rollover, which also is available online at www.nasa.gov/ntv.

The team will spend the rest of the afternoon and this weekend attaching Endeavour to its two solid rocket boosters and external fuel tank on the mobile launcher platform.

Training for the STS-130 crew members at NASA's Johnson Space Center in Houston focuses on practicing robotics techniques in the fixed-based simulator today.

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Robert Behnken

STS-130 Mission Specialist Robert Behnken, attired in a training version of his Extravehicular Mobility Unit spacesuit, awaits the start of a spacewalk training session in the waters of the Neutral Buoyancy Laboratory near NASA's Johnson Space Center.

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Color Dichotomy on Iapetus

Three different false-color views of Saturn's moon Iapetus show the boundary of the global "color dichotomy" on the hemisphere of this moon facing away from Saturn. The "color dichotomy," which has been detected in images from the Cassini imaging team, is a second global pattern found on Iapetus besides the well-known global brightness dichotomy.

This image consists of three panels, each of which was contrast-enhanced in different ways to bring out surface features. Minimal enhancement was applied to the image on the left panel while those on the middle and right panels were enhanced more (with contrast increased by factors of two and four, respectively), making them appear brighter and overexposed.

In the case of Iapetus' brightness dichotomy, the dark terrain extends towards the satellite's trailing side at equatorial regions, and the bright terrain extends towards the satellite's leading side in the polar regions (see PIA11116). In the case of the color dichotomy seen here, its boundary is quite well correlated with the boundary between the moon's leading and the trailing hemispheres. At near-infrared wavelengths, the bright terrain on the leading side is redder than on the trailing side. This pattern is visible in the panel on the left, which uses normal contrast enhancement. The characteristic reddish distribution also appears on the dark material, as seen in the middle and right-hand panels that have been adjusted with even higher contrast. Indeed, the otherwise uniformly dark material shows different color hues, depending on whether the viewer looks at the leading vs. the trailing side. Cassini scientists think this effect is caused by material falling onto Iapetus from the outer irregular moons of Saturn. See PIA06145 to learn more.

Images obtained with infrared, green and ultraviolet spectral filters (centered at 953, 563 and 338 nanometers, respectively) were combined to create these false color views. The color seen here is similar to that produced in (red, green and blue) natural color views.

North on Iapetus is approximately up in these images. The images were taken with the Cassini spacecraft narrow-angle camera on Oct. 15, 2004. The view was obtained at a distance of approximately 1.2 million kilometers (746,000 miles) from Iapetus and at a Sun-Iapetus-spacecraft, or phase, angle of 88 degrees. Image scale is 7 kilometers (4 miles) per pixel. The diameter of Iapetus is 1,471 kilometers (914 miles).

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for the Science Mission Directorate at NASA Headquarters in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

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Global View of Iapetus' Dichotomy

These two global images of Iapetus show the extreme brightness dichotomy on the surface of this peculiar Saturnian moon. The left-hand panel shows the moon's leading hemisphere and the right-hand panel shows the moon's trailing side. While low and mid latitudes of the leading side exhibit a surface almost as dark as charcoal, broad tracts of the trailing side are almost as bright as snow. The dark terrain covers about 40 percent of the surface and is named Cassini Regio. The names of the bright terrain are Roncevaux Terra (north) and Saragossa Terra (south).

On both hemispheres, the dominant landforms are impact craters. The largest known well-preserved basin on Iapetus, called Turgis, has a diameter of about 580 kilometers (360 miles). It lies at 17 degrees north latitude, 28 degrees west longitude at the eastern edge of the dark Cassini Regio and is visible on the right side of the left-hand panel. The prominent basin on the southern trailing side (at the lower left of the right-hand panel) is Engelier. Engelier is located at 41 degrees south latitude, 265 degrees west longitude, and has a diameter of about 504 kilometers (313 miles). Its formation destroyed about half of Gerin, another large basin on Iapetus. Gerin is located at 46 degrees south latitude, 233 degrees west longitude, and has a diameter of about 445 kilometers (276 miles). Tortelosa Montes, a part of the giant equatorial ridge that was discovered in Cassini images on December 25, 2004, is visible in the left panel as a thin line within Cassini Regio, and as a tall prominence at the western limb. It continues onto the trailing side (right side of right panel), where the bright western flanks of the Carcassone Montes appear as dominant bright spots within the western edge of Cassini Regio.

The cause of the extreme brightness dichotomy on Iapetus is likely to be thermal segregation of water ice on a global scale. Thermal effects are usually expected to act latitudinally. That is, polar areas are colder than equatorial terrain in most cases due to the more oblique angle of the solar irradiation. Therefore, an additional process is required to explain the longitudinal difference as well. In one model, dark, reddish dust coming in from space and preferentially deposited on the leading side forms a small, but crucial difference between the leading and trailing hemispheres, which is sufficient to allow the thermal effect to evaporate the water ice on the leading side completely, but only marginally on the trailing side. See PIA11689 to learn more. Iapetus' extremely slow rotation rate (1,904 hours), its distance from the sun, its relatively small size and surface gravity, and its outer position within the regular satellite system of Saturn are also crucial contributing conditions for this mechanism to work as observed.

North on Iapetus is approximately up in the images. Iapetus has a diameter of 1471 kilometers (914 miles).

The right-hand panel, released previously as PIA08384, shows a mosaic of 60 different images, obtained on September 10, 2007.

The left-hand panel is a color composite of three images obtained through infrared, green and ultraviolet spectral filters (centered at 752, 568 and 338 nanometers, respectively) by Cassini's narrow-angle camera on Dec. 27, 2004. The view was acquired at a distance of approximately 717,000 kilometers (446,000 miles) from Iapetus and at a sun-Iapetus-spacecraft, or phase, angle of 22 degrees.

Scale in the original image on the left was about 4 kilometers (2.5 miles) per pixel. For ease of comparison, the scales in both the left and right images were set to 1,400 meters (4,600 feet) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for the Science Mission Directorate at NASA Headquarters in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

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Rear Wheel Trouble Continues

Results of diagnostic tests on Spirit's right-rear wheel on Sol 2109 (Dec. 8, 2009) continue to indicate a troubled wheel, which may leave the rover with only four operable wheels.

The Sol 2109 plan included a check of the grind motor of Spirit's rock abrasion tool (RAT) because it shares the same motor controller as the right-rear wheel. It also included rotor resistance tests on the right-rear motor at three temperatures using opposite voltage polarity from earlier tests, backward and forward commanded motion of the right-rear wheel, and a check of rotor resistance on all other operating wheels. The RAT motor appears okay, although a more exhaustive test will be tried later. The right-rear wheel rotor resistance tests continue to show very elevated resistance, although not as high as in previous tests, and exhibiting a curious voltage-dependent effect. No motion of the right-rear wheel occurred during the backward commanded motion. The forward motion was not executed since the initial backward motion did not occur. The rotor resistances on all the other operating wheels are nominal.

The plan ahead, still being developed, will likely include more rotor resistance tests, an attempt to apply higher voltage to the right-rear wheel to see if any movement will occur, and a check of the right-front wheel to confirm its status and to see if it may offer insight into the right-rear wheel's condition. Further ahead, steering tests will be considered to explore an external jam as a possible explanation.

Concurrent with this, the project is exploring whether any meaningful rover motion would be possible with only four operable wheels. Spirit lost the use of its right front wheel in 2006.

Because of the current rover tilt, the environmental conditions and dust accumulation on the solar arrays, Spirit is at risk of inadequate power for surviving through the next southern Mars winter, which reaches solstice on May 13, 2009. Even if extrication is not possible, some limited rover motion may be able to improve rover tilt and increase the chance of winter survival.

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Endeavour's Move to VAB Set for Tomorrow

Technicians at NASA's Kennedy Space Center in Florida will hook up space shuttle Endeavour to the Orbiter Transporter System, or OTS, today. The transporter system will move the shuttle from its hangar in Orbiter Processing Facility-2 to the Vehicle Assembly Building, scheduled for 1 p.m. EST Friday.

The move, or rollover, is pending a review meeting tomorrow morning along with good weather.

The STS-130 astronauts are in the neutral buoyancy lab near NASA's Johnson Space Center in Houston today training for the second of three scheduled spacewalks.

Meanwhile, Commander George Zamka and Pilot Terry Virts will practice landing techniques in the T-38 and Shuttle Training Aircraft jets.

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New Date for Endeavour's Rollover

Space shuttle Endeavour will be moved from its hangar to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida a day earlier than planned.

First motion from Orbiter Processing Facility-2 to the VAB, is targeted for 1 p.m. EST on Dec. 11, pending good weather and approval from a review meeting scheduled for Friday morning.

Managers moved up the rollover after evaluating Endeavour's processing progress and confirming the change wouldn't adversely affect the team.

Forecasters are calling for possible bad weather on Saturday, so targeting rollover for Friday gives the team additional flexibility to make the move this week.

Once in the VAB, Endeavour will be attached to the waiting solid rocket boosters and external fuel tank for its STS-130 mission to the International Space Station, currently targeted to launch in early February.

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Spring Reveals Saturn's Hexagon Jet Stream

This movie from Cassini, made possible only as Saturn's north pole emerged from winter darkness, shows new details of a jet stream that follows a hexagon-shaped path and has long puzzled scientists.

The hexagon was hidden in darkness during the winter of Saturn's long year, a year that is equal to about 29 Earth years. But as the planet approached its August 2009 equinox and signaled the start of northern spring, the hexagon was revealed to Cassini's cameras. This is the first time the whole hexagonal shape has been mapped out in visible light by Cassini, and these images show unprecedented details of Saturn's high northern latitudes. The hexagon was originally discovered in images taken by Voyager spacecraft in the early 1980s. Since 2006, the Cassini Visual and Infrared Mapping Spectrometer (VIMS) instrument has been observing the hexagon at infrared wavelengths, but at lower spatial resolution than these visible light images.

Three large mosaics were used to create this three-frame movie. The mosaics used dozens of images and the constituent images were projected into polar projections to provide a complete view of the hexagon. The mosaics used in this movie do not show the region directly around the north pole because it had not yet fully emerged from the polar winter night. Seams between the images are visible in the third frame of the movie because the observation geometry in those images made removal of the seams difficult.

The six-sided shape remains a mystery. Scientists think the hexagon is a meandering jet stream at 77 degrees north latitude, but they don't know what controls the path the stream takes. These images also show new phenomena for scientists to decipher, such as waves that can now be seen radiating from the corners of the hexagon where the jet takes its hardest turns. These images confirm the presence of a multi-walled structure in each of the hexagon's six sides, and the structure now can be seen extending to the top of Saturn's cloud layer. The images show that the inside of the hexagon is darker than the outside. The new images also show a large spot inside the hexagon that could be related to a dark spot seen inside the hexagon in 2006 in an image taken by Cassini's VIMS instrument. An earlier Voyager mosaic showed a large spot outside the hexagon. That spot existed at least until 1991 before disappearing into the long winter polar night.

Images from Voyager and from ground-based telescopes suffered from poor viewing perspectives. In late 2006, Cassini's VIMS camera imaged the region in the thermal infrared wavelength, showing the hexagon in false color. Multiple images acquired by the VIMS instrument over a 12-day period showed that the feature is nearly stationary and is likely an unusually strong pole-encircling planetary wave that extends deep into the atmosphere. Scientists had speculated that a large vortex seen outside the hexagon during the Voyager observations exerted forces on the jet stream making it adopt a hexagonal pattern in a manner similar to how jet streams on Earth divert around high-pressure systems. However, in these new images, the vortex is notably absent while the hexagon persists almost 30 years after it was first seen.

The images were taken in visible light with the Cassini spacecraft wide-angle camera on Jan. 3, 2009. The images were obtained at a distance of approximately 764,000 kilometers (475,000 miles) from Saturn. The smallest resolved features at the latitude of the hexagon have a horizontal scale of approximately 100 kilometers.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for the Science Mission Directorate at NASA Headquarters in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

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Magnetic Power Revealed in Gamma-Ray Burst Jet

A specialized camera on a telescope operated by U.K. astronomers from Liverpool has made the first measurement of magnetic fields in the afterglow of a gamma-ray burst (GRB). The result is reported in the Dec.10 issue of Nature magazine by the team of Liverpool John Moores University (LJMU) astronomers who built and operate the telescope and its unique scientific camera, named RINGO.

The burst occurred January 2, 2009. NASA’s Swift satellite observed its position and immediately notified telescopes all over the world via the Internet. When it received the trigger from Swift, the robotic Liverpool Telescope on the island of La Palma in the Canary Islands automatically swung to observe the burst. Its special camera employs a spinning disk of Polaroid -- similar to the material used in sunglasses.

"By observing how the brightness of the GRB varied as we spun the Polaroid, we could measure the magnetic field in the burst," explained Iain Steele, Director of the Liverpool Telescope.

"This important result gives us new insight into the physics of these remarkable objects and is a testament to the close collaboration between observers, theoreticians and technologists in the Liverpool and NASA Swift teams," added LMJU team leader Carole Mundell. "It's incredible to think that the GRB discovery and our measurement process – from first detection and notification by NASA's Swift satellite to the polarization measurement using RINGO on the Liverpool Telescope – took place completely automatically within less than three minutes and with no human intervention!"

"This breakthrough observation gives us the first measurement of magnetic fields in the afterglow of a GRB," said Swift lead scientist Neil Gehrels, Swift lead scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

Gamma Ray Bursts form when the core of a massive star collapses or when two neutron stars merge together. The resulting explosions are the brightest events in the universe and vastly outshine entire galaxies containing hundreds of billions of stars. NASA’s Swift satellite sees about 100 of these events each year, triggering ground-based follow-up by observations across the globe.

Polarization is one of the least-observed properties in astronomy. This finding opens the door to understanding the role of magnetic fields in some of the most powerful events in the universe.

"These very interesting observations raise the possibility that gamma-ray bursts are not fireballs as usually presumed but are powered and collimated by an organized electromagnetic field," said Roger Blandford, Director of the Kavli Institute of Particle Astrophysics and Cosmology at Stanford University, California, commenting on the result's importance. "It will be very interesting to see if there are similarities in observations of other kinds of cosmic jets."

Funding for the operation of the Liverpool Telescope and GRB research at Liverpool JMU is provided by the U.K. Science and Technology Facilities Council. Swift is managed by NASA Goddard. It was built and is being operated in collaboration with Pennsylvania State University, the Los Alamos National Laboratory in New Mexico, and General Dynamics of Gilbert, Ariz., in the United States. International collaborators include the University of Leicester and Mullard Space Sciences Laboratory in the United Kingdom, Brera Observatory and the Italian Space Agency in Italy, and additional partners in Germany and Japan.

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SOFIA Aloft

An F/A-18 mission support aircraft shadows NASA's Stratospheric Observatory for Infrared Astronomy, or SOFIA, 747SP during a functional check flight Dec. 9, 2009. The flight included an evaluation of the aircraft's systems, including engines, flight controls and communication.

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Administrator Bolden Speaks at AAIA-WIA Luncheon

NASA Administrator Charles Bolden speaks during a luncheon co-hosted by the American Institute of Aeronautics and Astronautics (AIAA) and Women In Aerospace (WIA), Wednesday, Dec., 9, 2009 at the Ritz-Carlton in Arlington, Va.

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Garver Honors Four for Saving the Life of a Fifth at NASA Langley

Four men stood in an upstairs conference room Wednesday, each getting a medal from Lori Garver, NASA's deputy administrator.

A fifth told the gathering in the headquarters building at NASA's Langley Research Center that he had already gotten his award.

"Thanks guys," said Paul Roberts, 50, looking at his NASA Engineering and Safety co-workers, "for giving me back my life."

Garver gave Exceptional Bravery Medals to Jeff Stewart and Perry Wagner of Goddard Space Flight Center, Chip McCann of Johnson Space Center and Mike Kirsch, a Langley engineer and lead of the Composite Crew Module team.

She reminded everyone that NASA's products were produced by NASA's people.

"I am just so thrilled that you all were there," she told the foursome getting the awards.

"There" was a November 4 meeting in Langley's Building 1256, where the team was getting ready for a module test.

"We were sort of sitting back, looking at data, and suddenly he had his head back and it sounded like he was snoring," Wagner remembered of Roberts. "We were sort of kidding him that it looked like the meeting was boring him, but he didn't respond."

Stewart shook Roberts, and finding no response, laid him on the floor.

Wagner, McCann and Stewart immediately began administering CPR, as best they could remember how.

"I think I'd had the training most recently," McCann said, "and that was about six years ago."

Said Wagner: "I remember, like all of us, that we breathed on a mannequin in grade school. That was the last time."

Stewart was more specific. "About 34 years ago, when I was in the Boy Scouts."

But each took a role: Stewart working on Roberts' chest, Wagner doing mouth-to-mouth resuscitation when Roberts began to turn blue and McCann monitoring Roberts for a pulse rate.

"As soon as we put him down and tried to find a pulse on his wrist -- and actually I thought I felt a faint pulse there -- Jeff put his hand on Paul's chest and said 'I don't feel his heart beating here,' " McCann said. "By then, I didn't feel anything on his wrist, and that was the time Jeff started doing the compression."

The years since CPR training fostered uncertainty.

"It was a struggle for all of us," said McCann. "None of us were too sure what we were supposed to be doing. We were trying to do the basics."

Kirsch was organizing everyone else, creating an impromptu emergency center, calling 911, getting furniture out of the way for the arrival of paramedics and trying to reach NESC Director Ralph Roe by Instant Messenger to find the number of Roberts' wife, Ellen.

Stewart remembered an e-mail from his father-in-law a week earlier advising that the old "five compressions" method of CPR had been superseded by a recommended "30 compressions."

Wagner asked Stewart whether mouth-to-mouth was required, and finally Stewart said OK. "It's better to do it than not to do it," Wagner said. "I think I remember his color getting better."

Said Stewart: "Two to three minutes after we started to work on him, it looked like he was trying to come around. It kind of gave us impetus to keep going. It was, 'Wow, he's trying. We've got to keep going.'

"I had been taught that you had to press hard, almost to break his ribs, but I didn't want to break his ribs. That was why our communication was so important. As long as I got feedback from Chip that we were giving enough blood to him, I could keep going the way we were."

Within 7-10 minutes, Emergency Medical Treatment personnel came in to take over.

First, they told Stewart to continue chest compression. "But they told him to do it faster and harder," McCann said. "The first thing they said was 'Are you tired? Can you keep going?' "

Then the paramedics used a defibrillator to shock Roberts' heart.

"By the way, that wasn't much fun," said Roberts, laughing on Wednesday.

But one shock brought him back.

"Then Paul started talking," Stewart said. "He said 'Why am I on the floor? What happened?' "

Stewart filled him in on the ambulance ride to a local hospital, where a pacemaker was installed. The verdict was that Roberts had not had a heart attack, but that his electrical system had shut down. Also that without the CPR by his co-workers, Roberts probably would have died.

"Let me give you an idea of how important what these guys did was," Roberts said. "When I was in the hospital, I looked up some statistics on the Internet. When you go into sudden cardiac arrest and you have somebody in the room who sees you go down, the percentages are about 4-7 percent that you survive.

"About 30 percent of that 4-7 percent have almost no mental degradation. I think I'm in that 30 percent."

He laughed with everyone around him.

Lesa Roe, Langley's center director, and her Goddard and Johnson counterparts, Rob Strain and Mike Coats, echoed Garver's sentiments.

For Roberts, though, it was all personal.

"Guys, thanks for giving me back my family," he said.

Sitting at a table nearby, wife Ellen nodded her thanks, on behalf of their daughters, Katherine, Carolyn and Elizabeth.

And all of the men who received awards made early New Year's resolutions.

"CPR training is on my list," Kirsch said.

Roberts' list, too.

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