NASA Radar Penetrates Thick, Thin of Gulf Oil Spill
NASA UAVSAR image of the
Deepwater Horizon oil spill, collected June 23, 2010. The oil appears
much darker than the surrounding seawater in the greyscale image. This
is because the oil smoothes the sea surface and reduces its electrical
conductivity, causing less radar energy to bounce back to the UAVSAR
antenna. Additional processing of the data by the UAVSAR team produced
the two inset color images, which reveal the variability of the oil
spill's characteristics, from thicker, concentrated emulsions (shown in
reds and yellows) to minimal oil contamination (shown in greens and
blues). Dark blues correspond to areas of clear seawater bordering the
oil slick.
Images credit: NASA/JPL-Caltech › Larger image
October 25, 2012
PASADENA, Calif. - Researchers at and
the California Institute of Technology in Pasadena have developed a
method to use a specialized NASA 3-D imaging radar to characterize the
oil in oil spills, such as the 2010 BP Deepwater Horizon spill in the
Gulf of Mexico. The research can be used to improve response operations
during future marine oil spills.
Caltech graduate student Brent Minchew and JPL researchers Cathleen Jones and Ben Holt analyzed NASA radar imagery collected over the main slick of the BP Deepwater Horizon oil spill on June 22 and June 23, 2010. The data were acquired by the JPL-developed Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) during the first of its three deployments over the spill area between June 2010 and July 2012. The UAVSAR was carried in a pod mounted beneath a NASA C-20A piloted aircraft, a version of the Gulfstream III business jet, based at NASA's Dryden Aircraft Operations Facility in Palmdale, Calif. The researchers demonstrated, for the first time, that a radar system like UAVSAR can be used to characterize the oil within a slick, distinguishing very thin films like oil sheen from more damaging thick oil emulsions.
"Our research demonstrates the tremendous potential of UAVSAR to automate the classification of oil in a slick and mitigate the effects of future oil spill tragedies," said Jones. "Such information can help spill incidence response commanders direct cleanup operations, such as the mechanical recovery of oil, to the areas of thick oil that would have the most damaging environmental impacts."
Current visual oil classification techniques are qualitative, and depend upon the skill of the people doing the assessment and the availability of skilled observers during an emergency. Remote sensing allows larger areas to be covered in a consistent manner in a shorter amount of time. Radar can be used at night or in other low-light or poor weather conditions when visual surveys can't be conducted.
Radar had previously been used to detect the extent of oil slicks, but not to characterize the oil within them. It had generally been assumed that radar had little to no use for this purpose. The team demonstrated that UAVSAR could be used to identify areas where thick oil had mixed with the surface seawater to form emulsions, which are mixtures of oil and seawater.
Identifying the type of oil in a spill is vital for assessing its potential harm and targeting response efforts. For example, thin oil consists of sheens that measure from less than 0.0002 inches (0.005 millimeters) to about 0.002 inches (0.05 millimeters) thick. Sheens generally form when little oil is released, as in the initial stages of a spill, or from lightweight, volatile components of spill material. Because sheens contain little oil volume, they weather and evaporate quickly, and are of minor concern from an environmental standpoint. Oil emulsions, on the other hand, are 0.04 inches (1 millimeter) thick, contain more oil, and persist on the ocean surface for much longer, thereby potentially having a greater environmental impact in the open sea and along the shoreline.
"Knowing the type of oil tells us a lot about the thickness of the oil in that area," said Jones.
The researchers acquired data in June 2010 along more than 3,400 miles (5,500 kilometers) of flight lines over an area of more than 46,330 square miles (120,000 square kilometers), primarily along the Gulf Coast. They found that at the time the slick was imaged by UAVSAR, much of the surface layer of the Deepwater Horizon spill's main slick consisted of thick oil emulsions.
UAVSAR characterizes an oil spill by detecting variations in the roughness of its surface and, for thick slicks, changes in the electrical conductivity of its surface layer. Just as an airport runway looks smooth compared to surrounding fields, UAVSAR "sees" an oil spill at sea as a smoother (radar-dark) area against the rougher (radar-bright) ocean surface because most of the radar energy that hits the smoother surface is deflected away from the radar antenna. UAVSAR's high sensitivity and other capabilities enabled the team to separate thick and thin oil for the first time using a radar system.
"We knew we were going to detect the extent of the spill," said Holt. "But we had this great new instrument, so we wanted to see how it would work in this extreme situation, and it turned out to be really unique and valuable, beyond all previous radar results for spills."
"We studied an unprecedented event using data collected by a sophisticated instrument and were able to show that there was a lot more information contained in the data than was apparent when we began," said Minchew. "This is a good example of how the tools of science could be used to help mitigate disasters in real time."
UAVSAR is returning to the Gulf of Mexico area this month and will image the area around the Deepwater Horizon site to look for leaks. In the future, UAVSAR data may be combined with imaging spectroscopic data from JPL's Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) instrument to further improve the ability to characterize oil spills under a broader range of environmental conditions.
In addition to characterizing the oil slick, UAVSAR imaged most of the U.S. Gulf of Mexico coastline, extending from the Florida Keys to Corpus Christi, Texas, with extensive inland coverage of the southern Louisiana wetlands around Barataria Bay, the terrestrial ecosystem that ultimately sustained the greatest oiling from the massive spill. Researchers tracked the movement of the oil into coastal waterways and marshlands, monitored impact and recovery of oil-affected wetlands, and assessed how UAVSAR can support emergency responders in future disasters.
UAVSAR is also used to detect detailed Earth movements related to earthquakes, volcanoes and glaciers, as well as for soil moisture and forestry biomass studies. For more on UAVSAR, see: http://uavsar.jpl.nasa.gov/mission_flights.html .
Results of this study are published this month in the Institute of Electrical and Electronics Engineers journal Transactions on Geoscience and Remote Sensing. Caltech manages JPL for NASA.
Caltech graduate student Brent Minchew and JPL researchers Cathleen Jones and Ben Holt analyzed NASA radar imagery collected over the main slick of the BP Deepwater Horizon oil spill on June 22 and June 23, 2010. The data were acquired by the JPL-developed Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) during the first of its three deployments over the spill area between June 2010 and July 2012. The UAVSAR was carried in a pod mounted beneath a NASA C-20A piloted aircraft, a version of the Gulfstream III business jet, based at NASA's Dryden Aircraft Operations Facility in Palmdale, Calif. The researchers demonstrated, for the first time, that a radar system like UAVSAR can be used to characterize the oil within a slick, distinguishing very thin films like oil sheen from more damaging thick oil emulsions.
"Our research demonstrates the tremendous potential of UAVSAR to automate the classification of oil in a slick and mitigate the effects of future oil spill tragedies," said Jones. "Such information can help spill incidence response commanders direct cleanup operations, such as the mechanical recovery of oil, to the areas of thick oil that would have the most damaging environmental impacts."
Current visual oil classification techniques are qualitative, and depend upon the skill of the people doing the assessment and the availability of skilled observers during an emergency. Remote sensing allows larger areas to be covered in a consistent manner in a shorter amount of time. Radar can be used at night or in other low-light or poor weather conditions when visual surveys can't be conducted.
Radar had previously been used to detect the extent of oil slicks, but not to characterize the oil within them. It had generally been assumed that radar had little to no use for this purpose. The team demonstrated that UAVSAR could be used to identify areas where thick oil had mixed with the surface seawater to form emulsions, which are mixtures of oil and seawater.
Identifying the type of oil in a spill is vital for assessing its potential harm and targeting response efforts. For example, thin oil consists of sheens that measure from less than 0.0002 inches (0.005 millimeters) to about 0.002 inches (0.05 millimeters) thick. Sheens generally form when little oil is released, as in the initial stages of a spill, or from lightweight, volatile components of spill material. Because sheens contain little oil volume, they weather and evaporate quickly, and are of minor concern from an environmental standpoint. Oil emulsions, on the other hand, are 0.04 inches (1 millimeter) thick, contain more oil, and persist on the ocean surface for much longer, thereby potentially having a greater environmental impact in the open sea and along the shoreline.
"Knowing the type of oil tells us a lot about the thickness of the oil in that area," said Jones.
The researchers acquired data in June 2010 along more than 3,400 miles (5,500 kilometers) of flight lines over an area of more than 46,330 square miles (120,000 square kilometers), primarily along the Gulf Coast. They found that at the time the slick was imaged by UAVSAR, much of the surface layer of the Deepwater Horizon spill's main slick consisted of thick oil emulsions.
UAVSAR characterizes an oil spill by detecting variations in the roughness of its surface and, for thick slicks, changes in the electrical conductivity of its surface layer. Just as an airport runway looks smooth compared to surrounding fields, UAVSAR "sees" an oil spill at sea as a smoother (radar-dark) area against the rougher (radar-bright) ocean surface because most of the radar energy that hits the smoother surface is deflected away from the radar antenna. UAVSAR's high sensitivity and other capabilities enabled the team to separate thick and thin oil for the first time using a radar system.
"We knew we were going to detect the extent of the spill," said Holt. "But we had this great new instrument, so we wanted to see how it would work in this extreme situation, and it turned out to be really unique and valuable, beyond all previous radar results for spills."
"We studied an unprecedented event using data collected by a sophisticated instrument and were able to show that there was a lot more information contained in the data than was apparent when we began," said Minchew. "This is a good example of how the tools of science could be used to help mitigate disasters in real time."
UAVSAR is returning to the Gulf of Mexico area this month and will image the area around the Deepwater Horizon site to look for leaks. In the future, UAVSAR data may be combined with imaging spectroscopic data from JPL's Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) instrument to further improve the ability to characterize oil spills under a broader range of environmental conditions.
In addition to characterizing the oil slick, UAVSAR imaged most of the U.S. Gulf of Mexico coastline, extending from the Florida Keys to Corpus Christi, Texas, with extensive inland coverage of the southern Louisiana wetlands around Barataria Bay, the terrestrial ecosystem that ultimately sustained the greatest oiling from the massive spill. Researchers tracked the movement of the oil into coastal waterways and marshlands, monitored impact and recovery of oil-affected wetlands, and assessed how UAVSAR can support emergency responders in future disasters.
UAVSAR is also used to detect detailed Earth movements related to earthquakes, volcanoes and glaciers, as well as for soil moisture and forestry biomass studies. For more on UAVSAR, see: http://uavsar.jpl.nasa.gov/mission_flights.html .
Results of this study are published this month in the Institute of Electrical and Electronics Engineers journal Transactions on Geoscience and Remote Sensing. Caltech manages JPL for NASA.
Alan Buis 818-354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov
NASA Flies Radar South on Wide-Ranging Scientific Expedition
WASHINGTON
-- A versatile NASA airborne imaging radar system is showcasing its
broad scientific prowess for studying our home planet during a
month-long expedition over the Americas.
A NASA C-20A piloted aircraft carrying the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) is wrapping up studies over the U.S. Gulf Coast, Arizona, and Central and South America. The plane left NASA's Dryden Aircraft Operations Facility in Palmdale, Calif., on March 7. NASA's Jet Propulsion Laboratory in Pasadena built and manages UAVSAR.
The campaign is addressing a broad range of science questions, from the dynamics of Earth's crust and glaciers to the carbon cycle and the lives of ancient Peruvian civilizations. Flights are being conducted over Argentina, Bolivia, Chile, Colombia, Costa Rica, El Salvador, Ecuador, Guatemala, Honduras, Nicaragua and Peru.
UAVSAR uses a technique called interferometry that sends microwave energy pulses from the sensor on the aircraft to the ground. This technique can detect and measure subtle changes in Earth's surface like those caused by earthquakes, volcanoes, landslides and glacier movements. The radar's L-band microwaves can penetrate clouds and the tops of forests, making it invaluable for studying cloud-covered tropical environments and mapping flooded ecosystems.
"This campaign highlights UAVSAR's versatility for Earth studies," said Naiara Pinto, UAVSAR science coordinator at JPL. "In many cases, study sites are being used by multiple investigators. For example, some volcanic sites also have glaciers. The studies also help U.S. researchers establish and broaden scientific collaborations with Latin America."
Volcano scientists will compare UAVSAR's images taken during this campaign with new imagery collected in 2014 in order to measure very subtle sub-centimeter changes in Earth's surface associated with the movement of magma at depth beneath active volcanoes. These results are expected to improve models used to understand and potentially mitigate volcanic hazards. The volcanoes being studied are in Guatemala, El Salvador, Nicaragua, Costa Rica, Colombia, Ecuador, Peru, Bolivia, Chile and Argentina.
UAVSAR glacier data from South America's Andes Mountains will be combined with ground measurements and airborne lidar data to determine how much these glaciers move during summer and from year to year. The U.S. Geological Survey is leading the collaborative project with the Chilean government to understand glacier processes within the context of climate change impacts from human activities. The glaciers being imaged by UAVSAR provide freshwater for the residents of Santiago and water for regional agriculture.
This year's study sites include coastal mangroves in Central and South America. "Much of Earth's population lives along coasts, and its livelihood and well-being depend on services provided by marine ecosystems," said JPL's Marc Simard, one of the campaign's many principal investigators. "These regions are among the most fragile on Earth. It is critical to understand how the interactions of human activities and climate change may impact the sustainability of these ecosystems."
Another principal investigator, Kyle McDonald, jointly of JPL and the City University of New York, is leading four data collections that will support the mapping of wetlands across the greater Amazon River basin, including Pacaya-Samiria National Park in Peru. "Pacaya-Samiria contains large expanses of flooded palm swamps," McDonald said. "These ecosystems are potential major sources of atmospheric methane, an important greenhouse gas. UAVSAR will help us better understand processes involved with the exchange of methane between Earth's land and atmosphere, and with the contribution of these unique ecosystems to Earth's climate."
UAVSAR also is supporting agricultural studies of vineyards in Chile's La Serenas region. The efforts will help scientists at the Universidad de La Serena's Terra Pacific Group better understand the value of soil moisture data in grape and wine production. Another study site in Argentina will be overflown by both UAVSAR and the Argentine sensor SARAT as part of a collaboration between research scientist Thomas Jackson of the U.S. Department of Agriculture and Argentina's Comision Nacional de Actividades Espaciales. These studies assist scientists preparing for the launch of NASA's Soil Moisture Active Passive (SMAP) satellite in 2014.
The radar also is imaging the northern coastal Peruvian desert, where the Moche culture lived almost 2,000 years ago. Researchers are using UAVSAR's vegetation and cloud penetrating capabilities to search for unrecorded archaeological features in an attempt to preserve sensitive sites from encroaching civilization.
JPL researcher Sassan Saatchi is using UAVSAR to study the structure, biomass and diversity of tropical cloud forests in the Peruvian Andes and Manu National Park, continuing his work there during the past decade. The data will be used to evaluate how much carbon the forests contain and assess their vulnerability to human and natural disturbances.
UAVSAR also is monitoring seasonal land subsidence and uplift in groundwater basins in Arizona's Cochise County for the Arizona Department of Water Resources. Other subsidence studies in New Orleans and the Mississippi Delta are aimed at better understanding what causes Gulf Coast subsidence and predicting future subsidence rates. The data can help agencies better manage the protection of infrastructure, including levees in the New Orleans area.
For more information on UAVSAR, visit:
A NASA C-20A piloted aircraft carrying the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) is wrapping up studies over the U.S. Gulf Coast, Arizona, and Central and South America. The plane left NASA's Dryden Aircraft Operations Facility in Palmdale, Calif., on March 7. NASA's Jet Propulsion Laboratory in Pasadena built and manages UAVSAR.
The campaign is addressing a broad range of science questions, from the dynamics of Earth's crust and glaciers to the carbon cycle and the lives of ancient Peruvian civilizations. Flights are being conducted over Argentina, Bolivia, Chile, Colombia, Costa Rica, El Salvador, Ecuador, Guatemala, Honduras, Nicaragua and Peru.
UAVSAR uses a technique called interferometry that sends microwave energy pulses from the sensor on the aircraft to the ground. This technique can detect and measure subtle changes in Earth's surface like those caused by earthquakes, volcanoes, landslides and glacier movements. The radar's L-band microwaves can penetrate clouds and the tops of forests, making it invaluable for studying cloud-covered tropical environments and mapping flooded ecosystems.
"This campaign highlights UAVSAR's versatility for Earth studies," said Naiara Pinto, UAVSAR science coordinator at JPL. "In many cases, study sites are being used by multiple investigators. For example, some volcanic sites also have glaciers. The studies also help U.S. researchers establish and broaden scientific collaborations with Latin America."
Volcano scientists will compare UAVSAR's images taken during this campaign with new imagery collected in 2014 in order to measure very subtle sub-centimeter changes in Earth's surface associated with the movement of magma at depth beneath active volcanoes. These results are expected to improve models used to understand and potentially mitigate volcanic hazards. The volcanoes being studied are in Guatemala, El Salvador, Nicaragua, Costa Rica, Colombia, Ecuador, Peru, Bolivia, Chile and Argentina.
UAVSAR glacier data from South America's Andes Mountains will be combined with ground measurements and airborne lidar data to determine how much these glaciers move during summer and from year to year. The U.S. Geological Survey is leading the collaborative project with the Chilean government to understand glacier processes within the context of climate change impacts from human activities. The glaciers being imaged by UAVSAR provide freshwater for the residents of Santiago and water for regional agriculture.
This year's study sites include coastal mangroves in Central and South America. "Much of Earth's population lives along coasts, and its livelihood and well-being depend on services provided by marine ecosystems," said JPL's Marc Simard, one of the campaign's many principal investigators. "These regions are among the most fragile on Earth. It is critical to understand how the interactions of human activities and climate change may impact the sustainability of these ecosystems."
Another principal investigator, Kyle McDonald, jointly of JPL and the City University of New York, is leading four data collections that will support the mapping of wetlands across the greater Amazon River basin, including Pacaya-Samiria National Park in Peru. "Pacaya-Samiria contains large expanses of flooded palm swamps," McDonald said. "These ecosystems are potential major sources of atmospheric methane, an important greenhouse gas. UAVSAR will help us better understand processes involved with the exchange of methane between Earth's land and atmosphere, and with the contribution of these unique ecosystems to Earth's climate."
UAVSAR also is supporting agricultural studies of vineyards in Chile's La Serenas region. The efforts will help scientists at the Universidad de La Serena's Terra Pacific Group better understand the value of soil moisture data in grape and wine production. Another study site in Argentina will be overflown by both UAVSAR and the Argentine sensor SARAT as part of a collaboration between research scientist Thomas Jackson of the U.S. Department of Agriculture and Argentina's Comision Nacional de Actividades Espaciales. These studies assist scientists preparing for the launch of NASA's Soil Moisture Active Passive (SMAP) satellite in 2014.
The radar also is imaging the northern coastal Peruvian desert, where the Moche culture lived almost 2,000 years ago. Researchers are using UAVSAR's vegetation and cloud penetrating capabilities to search for unrecorded archaeological features in an attempt to preserve sensitive sites from encroaching civilization.
JPL researcher Sassan Saatchi is using UAVSAR to study the structure, biomass and diversity of tropical cloud forests in the Peruvian Andes and Manu National Park, continuing his work there during the past decade. The data will be used to evaluate how much carbon the forests contain and assess their vulnerability to human and natural disturbances.
UAVSAR also is monitoring seasonal land subsidence and uplift in groundwater basins in Arizona's Cochise County for the Arizona Department of Water Resources. Other subsidence studies in New Orleans and the Mississippi Delta are aimed at better understanding what causes Gulf Coast subsidence and predicting future subsidence rates. The data can help agencies better manage the protection of infrastructure, including levees in the New Orleans area.
For more information on UAVSAR, visit:
For more on NASA's Airborne Science program, visit:
NASA
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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