Partnership Successes

Industry Uses NASA Wind Tunnel to Design New Airplanes

NASA wind tunnel technology is being used by the aviation industry to improve new airplane designs throughout the entire development process.

Wing trailing edge design concepts for Boeing’s new 787 aircraft are being tested on a 5.2-percent scale 777 semi-span model inside Langley Research Center’s National Transonic Facility.

The National Transonic Facility is a unique wind tunnel developed by NASA that uses super-cold nitrogen gas at high pressure to duplicate true flight aerodynamics. Located at Langley Research Center, the facility can accommodate models as small as one-fiftieth the size of the actual aircraft. Unlike conventional wind tunnels, it can adjust the characteristics of the airflow to match the size of the model. Results help engineers determine how new designs will work for real planes in flight.

The Boeing Company is purchasing wind tunnel time in the facility to test new aviation concepts before applying them in flight. The Seattle-based manufacturer is specifically evaluating high-lift system designs for its new 787 jet aircraft. High-lift systems include flaps and slats that increase the lift performance of the wing, allowing the airplane to take off and land more safely and efficiently.

According to Rich Wahls, facility chief aerodynamicist, the wind tunnel’s ability to duplicate the aerodynamics of the flight environment, even with small-scale models, can allow aircraft manufacturers to produce better-performing airplanes with less risk.

To test the high-lift concepts, Boeing developers designed the new 787-style trailing edge flaps and fit them to an existing 5.2-percent scale 777 semi-span model. This stainless steel model, which looks like one-half of an airplane cut down the middle, from nose to tail, is mounted on the sidewall of the wind tunnel.

Improvements in design and performance are always a challenge, because of the complex airflow issues encountered when flaps and slats are extended from a wing. Fortunately, even small improvements in performance of a high-lift system can significantly improve the take-off field length, weight-carrying capability, and range of a transport aircraft. The improvements can also help reduce aircraft noise.

“In the past, engineers have come to the National Transonic Facility to further understand and solve problems with systems that have already been developed,” Wahls said. “Now we’re also seeing this test capability being used during the aircraft design phase.”

NASA Develops New Online De-Icing Training Course for Pilots

NASA has developed a free online course to help pilots avoid the hazards of ice contamination while their planes are on the ground. “A Pilot’s Guide to Ground Icing” is intended primarily for professional pilots who make their own de-icing and anti-icing decisions. It is the eighth in a series of training aids developed at Glenn Research Center, and the first on ground icing.

“The pilot community has asked for training materials to cover the full spectrum of icing concerns,” said Tom Bond, chief of Glenn’s Icing Branch. “Ground icing training complements our past work for in-flight icing training. NASA worked with an international group of aviation safety specialists from both regulatory and industry organizations to develop a training tool to aid pilots across international borders,” he added.

The development team included experts from Ames Research Center, the Federal Aviation Administration, Transport Canada, the Civil Aviation Authority (United Kingdom), the Canadian Armed Forces, the University of Oregon, a fractional jet provider, and an airline.

This self-guided course provides pilots with general ground icing knowledge, an understanding of freezing precipitation hazards, and the ability to improve decision making for ground icing operations. It discusses the risks of contamination, provides cues to alert pilots to ground icing conditions, and offers actions pilots can take to help ensure safe operations. Imagery, case studies, aviator testimonials, and interactive elements are all used to inform and help pilots.

Ground icing accidents are often preventable. Pilots will receive training to improve the safety of their flights from this online course.

“We are committed to supporting NASA’s goal to improve aviation safety. By helping pilots and operators understand the hazards of ground and in-flight aircraft icing, they can make better operational decisions,” said Dr. Judith Van Zante, icing researcher with the Cleveland-based QSS Group, Inc., and a team member at Glenn who was instrumental in developing the course.

The activity was supported by NASA’s Aviation Safety and Security Program Office, part of the Aeronautics Research Mission Directorate.

Previous training aids developed at Glenn focused on in-flight icing for various target pilot audiences. Titles include: Icing for Regional and Corporate Pilots; Icing for General Aviation Pilots; A Pilot’s Guide to In-Flight Icing; Tailplane Icing; and Supercooled Large Droplet Icing.

Instrument Provides Pilots With Improved Weather Forecasts

Weather forecasters throughout the United States are making better local predictions for pilots and others, thanks to an airborne sensor being tested by aviation safety experts at Langley.

Shown here is the TAMDAR instrument, a tiny sensor flown on commuter airliners to gather weather information.

These experts led a team that designed, built, and equipped dozens of Mesaba Airlines aircraft with the Tropospheric Airborne Meteorological Data Report (TAMDAR) instrument. Headquartered in Eagan, Minnesota, Mesaba is a Northwest Airlines affiliate that mainly flies short commuter routes.

The TAMDAR instrument allows aircraft to automatically sense and report atmospheric conditions. Observations are sent by satellite to a ground data center that processes and distributes up-to-date weather information to forecasters and pilots.

“Initial research shows the airborne sensor makes a 10- to 20-percent improvement in forecast error in numerical models—and that’s just with temperature,” said Taumi Daniels, NASA project leader.

The sensor also measures humidity, pressure, winds, icing, and turbulence, with the help of location, time,
and altitude provided by built-in Global Positioning System technology.

Large airliners fly above most weather and collect limited atmospheric data. When equipped with the weather sensor, regional aircraft, which typically fly below 25,000 feet, can provide more information. The information collected can also benefit weather models and forecasts, because it increases the number of observations in the lower atmosphere.

Currently, only 70 weather balloon sites in the continental United States collect temperature, wind, and moisture data from twice-daily atmospheric soundings. The TAMDAR experiment added 800 more daily atmospheric soundings.

“Meteorologists at the National Weather Service have found the Tropospheric Airborne Meteorological Data Report to be useful in forecasting severe thunderstorms, dense fog, precipitation types of winter storms, and low-level wind shear,” said Richard Mamrosh, a National Weather Service meteorologist in Green Bay, Wisconsin. “In summertime, its best use is in determining if and when thunderstorms might develop. In wintertime, it really helps in determining whether a storm will bring sleet, freezing rain, or snow,” he added.

The NASA partners analyzing the data are a mix of industry professionals, meteorologists, researchers, and scientists representing AirDat LLC, of Morrisville, North Carolina; the Federal Aviation Administration; the National Oceanic and Atmospheric Administration (NOAA); the National Center for Atmospheric Research; the Massachusetts Institute of Technology Lincoln Laboratory; the Meteorological Service of Canada, in Montreal; the Met Office, in London; and the meteorological network of Europe (EUNETMET), in Toulouse, France.

The TAMDAR project is part of NASA’s Aeronautics Research Mission Directorate.

Major Weather Forecasting Advancement

In another weather forecasting breakthrough, NASA and NOAA have outlined research that has helped to improve the accuracy of medium-range weather forecasts in the Northern Hemisphere.

NASA’s Atmospheric Infrared Sounder instrument is able to peel back cloud cover to reveal 3-D data of a storm’s water vapor content—information that can be used to improve weather forecast models.

NASA and NOAA scientists at the Joint Center for Satellite Data Assimilation, in Camp Springs, Maryland, came up with procedures to improve forecasting accuracy. The scientists worked with experimental data from the Atmospheric Infrared Sounder(AIRS) instrument on NASA’s Aqua satellite. AIRS is a high-spectral resolution, infrared instrument that takes 3-D pictures of atmospheric temperatures, water vapor, and trace gasses.

The scientists found that, by incorporating the instrument’s data into numerical weather prediction models, they can improve the accuracy range of experimental, 6-day, Northern Hemisphere weather forecasts by up to 6 hours—a 4-percent increase.

“This AIRS instrument has provided the most significant increase in forecast improvement in this time range of any other single instrument,” said retired Navy Vice Admiral Conrad C. Lautenbacher, Jr., Ph.D., undersecretary of commerce for oceans and atmosphere and NOAA administrator. “Climate and weather forecasts are dependent upon our understanding current global ocean and atmosphere conditions,” added Lautenbacher. “If we want to be able to predict what the weather will be like in the future, we must adequately define the global conditions today. Satellite data, like AIRS provides, is a vital link for NOAA to take the pulse of the planet continuously.”

“A 4-percent increase in forecast accuracy at 5 or 6 days normally takes several years to achieve,” said Dr. John Le Marshall, Joint Center for Satellite Data Assimilation director. “This is a major advancement, and it is only the start of what we may see as much more data from this instrument are incorporated into operational forecast models at NOAA’s Environmental Modeling Center.”

“NASA is assisting the world’s weather-prediction agencies by providing very detailed, accurate observations of key atmospheric variables that interact to shape our weather and climate,” said Dr. Mary Cleave, associate administrator for NASA’s Science Mission Directorate. “The forecast improvement accomplishment alone makes the AIRS project well worth the American taxpayers’ investment.”

The instrument’s data have been officially incorporated into NOAA’s National Weather Service operational weather forecasts. Elsewhere, the European Centre for Medium-Range Weather Forecasts began incorporating data from AIRS into its operational forecasts in October 2003. The center reported an improvement in forecast accuracy of 8 hours in Southern Hemisphere 5-day forecasts.

The AIRS instrument is the result of more than 30 years of atmospheric research, led by Dr. Moustafa Chahine of the Jet Propulsion Laboratory (JPL).

The Joint Center for Satellite Data Assimilation is operated by NOAA, NASA, the U.S. Air Force, and the U.S. Navy. The goals of the center are to accelerate the use of observations from Earth-orbiting satellites to improve weather and climate forecasts, and to increase the accuracy of climate data sets.

Study Suggests Ways to Beat the Heat in New York City

The heat is on in New York City, whether it is summer or winter. This is due to a phenomenon called urban heat island effect that causes air temperatures in New York City and other major cities to be warmer than in neighboring suburbs and rural areas. In a big city, warmer air temperatures can impact air quality, public health, and the demand for energy.

Several innovative approaches developed by scientists, public officials, environmental activists, community organizations, and others have been put in place to take a bite out of the Big Apple’s temperature problem. NASA researchers, using NASA satellite observations, weather pattern data, and computer models, conducted a study to assess how well those strategies are working.

This image indicates case study areas and weather stations used in the NASA study on urban heat island effect in New York City

“We need to help public officials find the most successful ways to reduce the heat island effect in New York. With ever-increasing urban populations around the world, the heat island effect will become even more significant in the future,” said Stuart Gaffin, an associate research scientist at Columbia University and a co-author of the NASA study. “The summertime impacts are especially intense with the deterioration of air quality, because higher air temperatures increase ozone. That has health effects for everyone. We also run an increased risk of major heat waves and blackouts, as the heat island effect raises demand for electricity.”

Land surfaces with vegetation are relatively sparse in large cities, dominated instead by non-reflective, water-resistant surfaces, such as asphalt, tar, and building materials that absorb most of the Sun’s radiation, causing the urban heat island effect. These surfaces hinder the natural cooling that would otherwise take effect with the evaporation of moisture from surfaces with vegetation.

The urban heat island occurrence is particularly pronounced during summer heat waves and at night when wind speeds are low and sea breezes are light. During these times, New York City’s air temperatures can rise 7.2 °F higher than temperatures in surrounding areas.

In the NASA project, researchers set out to recommend ways to reduce the urban heat island effect in New York City. Their recommendations included promoting light-colored surfaces—especially for roofs and pavements—that reflect sunlight, planting “urban forests,” and creating “living roofs” on building tops where sturdy vegetation can be planted and can thrive. Using a regional climate computer model, the researchers wanted to calculate how these strategies could lower the city’s surface and close-to-surface air temperatures, and how they would affect New York’s energy system, air quality, and the health of its residents.

In addition to the city-wide case study, NASA researchers also conducted six smaller case studies across Lower Manhattan, the Bronx’s Fordham section, Brooklyn’s Crown Heights section, and the Maspeth area of Queens. These areas were chosen for the different ways land is used and their close proximity to other areas with high electrical use. They also had warmer-than-average near-surface air temperatures called “hot spots” and available spaces to test ways to reduce the urban heat island effect.

“We found that vegetation is a powerful cooling mechanism. It appears to be the most effective tool to reduce surface temperatures,” Gaffin said. “Another effective approach is a manmade approach to cooling, by making very bright, high albedo, or reflected light, on roof tops. These light-colored surfaces, best made using white coatings, reflect the Sun’s light and, thereby, its heat. Interestingly, more area is available to create the lighter surfaces than to add vegetation in a city such as New York.”

This study was sponsored by the New York State Energy Research and Development Authority, the New York State Department of Environmental Conservation, and the U.S. Department of Agriculture Forest Service. Detailed results were presented during the 2006 American Meteorological Society’s annual meeting.

Space-Rooted Telemedicine Aids Earthquake Victims

Scientists at a NASA research partnership center used space medical-monitoring technology to help earthquake victims in Pakistan. The tents pictured here served as field hospitals for patients who experienced “crush” injuries incurred from falling concrete caused by the earthquake.

Scientists at a NASA research partnership center have put space medical-monitoring technology to humanitarian use in helping earthquake victims in Pakistan.

Drs. Ronald Merrell and Azhar Rafiq, of Virginia Commonwealth University’s Medical Informatics and Technology Applications Consortium (MITAC), went overseas in January to teach telemedicine techniques in Rawalpindi, Pakistan, a region hit hard by an October 10, 2005 earthquake that killed more than 80,000 people and left 3.5 million homeless. The physicians taught medical practitioners from remote mountainous regions how to provide cutting-edge health care, using technology that was originally developed for astronauts on long-term missions to the Moon.

In addition to this work, Merrell and Rafiq were also invited by the U.S. Department of State and the U.S. Department of Defense Telemedicine and Advanced Technology Research Center to complete a telemedicine training program consisting of online and videoconference lectures for the medical college at Holy Family Hospital in Rawalpindi. Pakistani teams that complete this training program can become qualified to use electronic scopes and medical cameras for skin evaluations, the results of which can then be submitted to a hub at the medical college for consultation and treatment recommendations.

“The skin reveals a lot about our health,” said Rafiq, who, while in Pakistan, provided a daily log of his personal observations for NASA’s Web site. “Clammy, cold skin can be a sign of hypothermia, while moist, hot skin may indicate fever from an infection. With the continuum of virtual information available through telemedicine, we can apply some of the same diagnostic techniques and treatment on Earth that we are developing for space exploration.”

AMD Telemedicine, Inc., a leading provider of telemedicine equipment located in Lowell, Massachusetts, is an industry partner with MITAC and the donor of the medical equipment for the Pakistan project, including the electronic stethoscopes and medical cameras.

NASA and University Scientists Uncover Lost Maya Ruins—From Space

Remains of the ancient Maya culture, mysteriously destroyed at the height of its reign in the 9th century, have been hidden in the rainforests of Central America for more than 1,000 years. Now, NASA and university scientists are employing space- and aircraft-based remote sensing technology to uncover these ruins, using the chemical signature of the civilization’s ancient building materials.

Deep in the Guatemalan jungle, NASA archaeologist Dr. Tom Sever, right, and team member Rob Griffin, a graduate student at Penn State University, study a crumbled “stele,” a stone pyramid used by the Maya to record information or display ornately carved art. Sever and Griffin found the stele—and other Maya ruins hidden for more than 1,000 years—during an expedition that relied on NASA remote sensing technologies to pinpoint sites of ancient settlements. Sever and fellow researcher Dan Irwin, both of Marshall Space Flight Center, have teamed with archaeologist Dr. William Saturno of the University of New Hampshire, to demonstrate how high-resolution satellite imaging can reveal variations in plant life indicative of ancient building sites.

NASA archaeologist Dr. Tom Sever and scientist Dan Irwin, both from Marshall Space Flight Center, are teaming with Dr. William Saturno, an archaeologist at the University of New Hampshire, to locate the ruins of the ancient culture.

“From the air, everything but the tops of very few surviving pyramids [is] hidden by the tree canopy,” said Sever, widely recognized for 2 decades as a pioneer in the use of remote sensing for archaeology. “On the ground, the 60- to 100-foot trees and dense undergrowth can obscure objects as close as 10 feet away. Explorers can stumble right through an ancient city that once housed thousands—and never even realize it.”

Sever has explored the use of remote sensing, the science of collecting information about the Earth’s surface using aerial or space-based photography, to serve archaeology. He and Irwin provided Saturno with high-resolution, commercial satellite images of the rainforest and collected data from NASA’s Airborne Synthetic Aperture Radar, an instrument flown aboard a high-altitude weather plane, capable of penetrating clouds, snow, and forest canopies.

These resulting Earth observations have helped the team survey an uncharted region around San Bartolo, Guatemala. It discovered a correlation between the color and reflectivity of the vegetation seen in the images—their “signature,” which is captured by instruments measuring light in the visible and near-infrared spectrums—and the location of known archaeological sites.

In 2004, the team ground-tested the data. Hiking deep into the jungle to locations guided by the satellite images, it uncovered a series of Maya settlements exactly where the technology had predicted they would be found. Integrating cutting-edge remote sensing technology as a vital research tool enabled the scientists to expand their study of the jungle.

The cause of the floral signature differences discerned in the imagery quickly became clear to the team. The Maya built their cities and towns with excavated limestone and lime plasters. As these structures crumbled, the lack of moisture and nutritional elements inside the ruins kept some plant species at bay, while others were discolored or killed off altogether, as disintegrating plaster changed the chemical content of the soil around each structure.

“Over the centuries, the changes became dramatic,” Saturno said. “This pattern of small details, impossible to see from the forest floor or low-altitude planes, turned out to be a virtual roadmap to ancient Maya sites when seen from space.”

According to Irwin, scientists believe the Maya fell prey to a number of cataclysmic environmental problems, including deforestation and drought, that led to their downfall. “The world continues to battle the devastating effects of drought today, from the arid plains of Africa to the southern United States,” he said. “The more we know about the plight of the Maya, the better our chances of avoiding something similar.”

Another aspect of the research involved using climate models to determine the effects of Maya-driven deforestation on ancient Mesoamerican climate. The goal of this effort was to determine whether deforestation can lead to droughts and if the activities of the ancient Maya drove the environmental changes that undermined their civilization.

Extending benefits of remote sensing technologies is part of NASA’s Earth-Sun System Division. NASA is conducting a long-term research effort to learn how natural and human-induced changes affect the global environment, and to provide critical benefits to society today.

Sever and Irwin conduct research at the National Space Science and Technology Center, in Huntsville, a joint science venture between Marshall, Alabama universities, industry, and Federal agencies.

Under a NASA Space Act Agreement with the University of New Hampshire, the science team will visit Guatemala annually through 2009, with the support of the Guatemalan Institute of Anthropology and History and the Department of Pre-Hispanic Monuments. The team will verify its research and continue refining its remote sensing tools to more easily lead explorers to other ancient ruins and conduct Earth science research in the region.

“Studies such as these do more than fulfill our curiosity about the past,” Sever said. “They help us prepare for our own future.”

NASA Responds to Coral Bleaching in the Caribbean

This aerial image of Buck Island, off of St. Croix, was taken with a Cirrus Digital Camera System. This camera system flew on NASA’s Twin Otter aircraft, along with the NASA Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), to assist researchers in their efforts to better understand and predict coral bleaching.

As part of a U.S. interagency response, a NASA-led team arrived in the Caribbean to assess a coral-bleaching event in early 2006.

Coral bleaching is associated with a variety of stresses, including increased sea surface temperatures. This causes the coral to expel symbiotic micro-algae living in their tissues—algae that provide it with food. Losing algae leaves coral tissues devoid of color, given them a bleached appearance. Prolonged coral bleaching (more than a week) can lead to coral death and the subsequent loss of habitats for a range of marine life.

“Coral reefs are considered ‘canaries of the oceans,’ acting as an early warning system for marine ecosystems,” said Liane Guild, a scientist at Ames. Guild led the NASA emergency deployment to rapidly assess the damage before other changes could take place in the affected reefs.

“I’m very pleased to have NASA step up and bring its expertise and assets to help the scientific community understand and address this devastating event,” said Timothy Keeney, deputy assistant secretary of commerce for oceans and atmosphere.

The NASA-led interagency team inspected reefs in Puerto Rico, including sites at La Parguera and Culebra Island, and sites in the U.S. Virgin Islands, including Buck Island, the north coast of St. Croix, and the south coast of St. John.

With financial support and staff from NOAA, the U.S. Department of the Interior, and other agencies, NASA conducted aircraft flyovers above the affected reefs to gather valuable data.

The team’s Twin Otter aircraft—supplied by Goddard Space Flight Center—inspected the bleached reef areas using a digital camera and the NASA Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), an instrument that captures visible and infrared light data. The aircraft-based sensors provide high spectral and spatial resolution data and can be used to enhance understanding of ocean biology satellite data.

“The importance of this research is that we will be concentrating on aspects that enhance both understanding and prediction of reef status in terms of the extent of bleached corals, coral mortality, evidence of recovery, evidence of algal overgrowth, and biodiversity, using AVIRIS data and field measurements,” Guild said.

NASA, NOAA, and other organizations also supported field monitoring to complement the flyover. Guild’s field team was in the water when the flights occurred, collecting data on the coral that related to the AVIRIS data.

Coral reefs are critical for marine fisheries, providing habitat and nursery grounds, according to experts. “The structure of coral reefs provides coastline protection from severe storms by dampening wave action,” Guild said.

The research done by the team that assessed the potential impact of a changing climate on global ecology supports U.S. Climate Change Science Program and U.S. Ocean Action Plan objectives.

The NASA-NOAA effort was just one component of the response. Many other efforts were started to help document and track this bleaching event and its long-term impacts on Caribbean coral reef ecosystems and the communities that depend on them.

Other partners in this study included researchers from the University of Puerto Rico, NOAA’s Coral Reef Conservation Program, and the National Park Service in the U.S. Virgin Islands.

NASA and Industry Test Aircraft Noise-Reducing Technologies

NASA and aerospace industry partners are flight testing new technologies to see if they can make aircraft quieter. Scalloped edges on engine exteriors and toboggan-like fittings on landing gear are some of the high-tech ideas being tested to reduce aircraft noise.

Experts at Langley and industry team researchers developed advanced noise-reduction concepts and tested them, initially, using wind tunnels and computer simulations.

With the initial conceptual testing completed, the team assessed the ideas and actual hardware at a test flight facility in Glasgow, Montana. The researchers used a large, specially equipped 777 passenger jet provided by The Boeing Company. The test facility was outfitted with sophisticated microphone arrays and other measurement devices to record noise levels.

The Quiet Technology Demonstrator 2 was a 3-week test flight program to validate the ideas, including two improved chevron designs on the engine and a cover that fits on the landing gear. Chevrons are scalloped or serrated edges already used on some newer jet engines. One improved chevron design included asymmetrical scallops around the engine.

“The new design tailors the chevrons to take into account the air flow and acoustic differences that occur when the engine is installed on the aircraft,” said Charlotte Whitfield, NASA’s Quiet Aircraft Technology manager of airframe system noise reduction.

Laboratory tests showed the advanced chevron shape will reduce noise as much as 4 decibels during takeoff and when flying at cruise altitude. Results of the flight tests may lead to changes in aircraft configurations, and future airplane engine and landing gear designs.

Goodrich Corporation’s Aerostructures and Landing Gear divisions designed and built a toboggan-like shaped cover for the 777’s main landing gear.

The cover streamlines the gear and makes it less noisy. NASA and Goodrich tested this concept in a wind tunnel on a 26-percent scale model of the 777 landing gear. NASA research indicated that, when landing, air rushing past conventional landing gear is almost as loud as engine noise. The covered gear concept could reduce landing noise by another 3 decibels.

After completing the testing, Boeing delivered the new technology-equipped 777 to All Nippon Airways (ANA), in Tokyo. The aircraft joined the ANA passenger fleet and will provide additional noise data based on regular operations. GE Transportation Aircraft Engines, of Cincinnati, also participated in the research.

NASA Helps Weed the National Garden

NASA and other Federal agencies are using satellites that circle the Earth to help weed out a plant that is affecting water supplies in the western United States.

NASA has been using its satellite and computer resources to help other organizations control invasive plant species. An invasive species is a non-native species or species that is alien to the ecosystem in which it is found. Often, invasive species cause economic or environmental harm, or pose risks to human health. Invasive species can be plants, animals, and other organisms (such as microbes). Human actions are the primary means of invasive species introductions.

Invasive plant species are traditionally located, identified, and monitored by manual ground surveys. Such surveys are effective, but expensive, time consuming, and difficult to manage over large areas. Now, a new tool developed by the U.S. Geological Survey (USGS) is taking advantage of observations from NASA satellites and NASA engineering to provide a service for land managers that predicts quickly and inexpensively the location and spread of invasive plants over regional areas. The tool, called the Invasive Species Forecasting System (ISFS), was recently used to make the first predictive map of tamarisk—sometimes called saltcedar—habitats in the United States. Tamarisk is a large deciduous shrub, sometimes growing to the size of a small tree, and native to Africa and Eurasia. It was introduced in the western United States in the early 1800s as “ornamental vegetation” and for wind and erosion control.

Tamarisk has since spread and can be found from Minnesota to California and from Mexico to Canada. The U.S. Department of Agriculture recently identified tamarisk as one of the most harmful invasive species in the Nation, because the plant’s long roots tap into underground aquifers. Its groundwater-absorbing qualities may be adding to the severity of the drought in the western United States. Tamarisk also increases the salt concentration of the soil and degrades habitats for native species along river systems.

Researchers now estimate that tamarisk has infested more than 3.3 million acres in the western United States. With the invasion spreading like wildfire, this invasive species poses a serious threat to the West’s water supply

“The ISFS combines NASA satellite data with tens of thousands of field sampling measurements,” said Tom Stohlgren, director of the USGS National Institute of Invasive Species Science. All of the data are then used to look at where non-native plants existed in the past, or where they exist today. Then, the ISFS tool can help predict where the invasive plants may grow or spread. People that manage lands, especially water supplies in the U.S. West, can use the color-coded maps that the ISFS produces to help predict and manage the spread of troublesome invasive species.

ISFS uses data from NASA’s Terra, Aqua, and Earth Observing-1 satellites, and the USGS Landsat satellites, together with field data from government and non-government contributors. All of these satellites observe and measure sunlight reflected by plants and the environments in which they are growing. The satellites are able to lock in on some of the reflected light to determine tamarisk’s current locations, as well as places where it may spread.

“Satellite data and computer modeling helps us understand where tamarisk is likely to be growing, even in remote locations that field researchers cannot easily reach,” said John Schnase, principal investigator of the ISFS project at Goddard.

Currently, USGS is using the ISFS to predict the spread of other invasive species, such as cheatgrass, Canadian star thistle, and certain aquatic species.

Scientists Get a Real ‘Rise’ Out of Breakthroughs in Understanding Changes in Sea Level

For the first time, researchers have the tools and expertise to understand the rate at which sea levels are changing and the mechanisms that drive that change.

Sea levels rise and fall as oceans warm and cool and as ice on land grows and shrinks. Other factors that contribute to sea level change are the amount of water stored in lakes and reservoirs and the rising and falling of land in coastal regions.

“From the Mississippi Delta, to the Maldives Islands off the coast of India, to the multitude of other low-lying coastal areas around the world, it is estimated that over 100 million lives are potentially impacted by a 3-foot increase in sea level,” said Dr. Waleed Abdalati, head of the Cryospheric Sciences Branch at Goddard. “This is an ideal time, during the midst of a historic year of both related natural events and research developments tied to this critical global issue, to talk to the public about whether ice in our polar regions is truly melting, whether our oceans are indeed rising faster, and what these changes may mean to us.”

Changes in sea level entail a complex array of conditions, from chemistry and temperature, to changes in the shape of the basins that hold the world’s water. This advanced computer model shows the span of sea temperatures across the globe. Recent research indicates that ice cover is shrinking much faster than thought, with over half of recent sea level rise due to the melting of ice from Greenland, West Antarctica’s Amundsen Sea, and mountain glaciers.

NASA is taking advantage of its unique, space-based satellite observations of Earth’s oceans and atmosphere, in combination with satellite observations and sea surface measurements from domestic and international partners, to learn more about why and how the world’s waters are rising. In doing so, the Agency is hoping to determine more about factors leading to sea level change, indicators of change such as ocean expansion, changes in ice, impoundment of water, and movement of earth and coastal regions, and how the latest research developments contribute to our knowledge of sea level rise.

NASA is working with NOAA, the National Science Foundation, and others to explore and understand sea level change—to tell the story of what is happening. NASA satellite missions devoted to sea level research include: the Gravity Recovery and Climate Experiment (GRACE), which maps Earth’s gravitational field with precision and resolution, and whose data helps us better understand movement of water throughout the Earth; the Ocean TOPography EXperiment (TOPEX/Poseidon), a joint U.S./French satellite that uses radar to map the precise features of the oceans’ surfaces; The JASON Project, which measures ocean height and monitors ocean circulation; and the Ice, Cloud, and Land Elevation Satellite (ICESat), whose primary purpose is to study the mass of polar ice sheets and their contributions to global sea level change.

According to Dr. Laury Miller, chief of the NOAA Laboratory for Satellite Altimetry, the big news that has emerged over the past few years is that the rate of 20th century sea level rise is about 2 millimeters per year and that only a quarter of this is due to expansion caused by warming of the oceans. This provides an important context for these recent observations.

“We’ve found that the largest likely factor for sea level rise is changes in the amount of ice that covers Earth. Three-fourths of the planet’s fresh water is stored in glaciers and ice sheets, or about 220 feet of sea level,” said Dr. Eric Rignot, principal scientist for the Radar Science and Engineering Section at JPL. Research results by Rignot and partners, published in an October 2004 article in Science magazine, offer further evidence that ice cover is shrinking much faster than previously thought, with over half of recent sea level rise due to the melting of ice from Greenland, West Antarctica’s Amundsen Sea, and mountain glaciers.

The latest sea level research conducted by Dr. Steve Nerem, associate professor at the Colorado Center for Astrodynamics Research at the University of Colorado at Boulder, and his colleagues, and published in a 2004 issue of Marine Geodesy, has found that recent TOPEX/Poseidon and JASON satellite observations show an average increase in global mean sea level of 3 millimeters a year, from 1993 to 2005. This rate is more than 50 percent greater than the average rate of the last 50 years.

“Now the challenge is to develop an even deeper understanding of what is responsible for sea level rise and to monitor for possible future changes. That’s where NASA’s satellites come in with global coverage, and ability to examine the many factors involved,” said Miller.