Gulf of Mexico Initiative Targets Oil Spills and Other Ecological Challenges
Viewing the Deepwater Horizon BP oil spill in the Gulf of Mexico Gulf from 438 miles (705 km) away can be quite different from seeing it in person. But for NASA, the satellite view of the oil spill can be very informative.

A May 6 photo of a slick caused by the Deepwater Horizon oil spill
Click to enlarge

A May 6 photo of a slick caused by the Deepwater Horizon oil spill.
Credit: NRL & USGS.

NASA scientists and research partners are working closely to provide satellite data to those who need it in the wake of the disaster. One such scientist is Sonia Gallegos, of the Naval Research Laboratory (NRL), who recently spent several days on a boat seeing the effects of the oil spill first hand.

This project, which proposes to use NASA's active and passive remote sensing capabilities to monitor oil slicks, was funded by NASA six months ago and got a serious jump start three weeks ago when the Deepwater Horizon BP oil rig caught fire and sunk.

This project is part of a larger effort by NASA's Applied Sciences Program to address coastal management issues in the Gulf of Mexico. NASA's Gulf of Mexico Initiative began in response to the impact of hurricanes Katrina, Dennis, Rita and Wilma in 2005 and overall is intended to enhance the ecological and economic health of the Gulf. NASA is working to achieve these goals through use of expertise in remote sensing, oceanography, coastal processes, signal processing and mathematical modeling.

"Over the past two years, the NASA Applied Sciences Program has invested over $18 million to create a suite of projects that will enhance the Gulf of Mexico region's ability to use NASA Earth science observations and research in decision-making activities," said John Haynes, program manager of the initiative.

"Use of NASA Earth science research by operational partners in the Gulf region will help the area to plan for a sustainable and prosperous future," he said, "as well as be better able to respond to natural disasters and environmental threats, such as the current oil spill."

The latest NASA visible satellite image of the slick on May 11 at 18:55 UTC (2:55 p.m. EDT) resembles a swan
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The NASA satellite image of the slick on May 11 at 18:55 UTC (2:55 p.m. EDT) resembles a swan.
Credit: NASA

Before Gallegos went on the Gulf field campaign, she had seen the spill only through the eyes of satellites. Gallegos pulled data from two NASA instruments. One was MODIS (Moderate Resolution Imaging Spectroradiometer), which flies on the Terra and Aqua satellites. The other was the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) instrument on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite.

All three fly 438 miles (705 km) above the Earth. MODIS provides a wide view of the oil spill approximately twice a day during clear weather conditions. CALIPSO may be able to tell scientists the density of the oil by reflecting backscattered light transmitted from a space-based laser called lidar.

Gallegos' field samples will be used to validate the location of the oil slicks for the CALIOP instrument. The data collected in the Gulf will also be used to calibrate NASA airborne sensors such as AVIRIS (Airborne Visible/Infrared Imaging Spectrometer). The combination of AVIRIS and the lidar data from CALIPSO are the tools that allow estimation of the amounts of oil at the surface of the water.

"MODIS provided an unparalleled view of the entire oil spill and CALIOP gave a pretty good perspective of the layers of volatile organic compounds (VOCs, an oil byproduct) that occurred over the spill, helping us to identify the extent of the spill," said Gallegos. When the oil reaches the surface of the water it comes into contact with the air and releases VOCs.

Researchers at first thought they were seeing emissions from efforts to burn off surface oil in data being sent from CALIPSO. However, once Gallegos was there in person, she saw that the emissions were actually volatile compounds released from oil at the surface.

CALIOP view of the Deepwater Horizon oil spill on May 2, 2010
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CALIOP view of the Deepwater Horizon oil spill on May 2, 2010. Red indicates the location of the aerosols over the spill.
Credit: NASA

Gallegos is using satellite data in conjunction with field observations and Synthetic Aperture Radar (SAR) data to map the oil spill and measure its impact on marine life. Once these data are verified, and an algorithm is created, it will be sent to the National Oceanic and Atmospheric Administration (NOAA) Emergency Response Division. With this information NOAA will be better able to view the depth and breadth of the oil spill and respond accordingly.

Gallegos is working on comparing some of the satellite data with her first-hand observations, but the volume of data and observations is a bit overwhelming.

"I did not expect an incident of this magnitude to occur when I was peacefully working on my algorithms," said Gallegos.

This project is only one of several projects under the Gulf of Mexico Initiative that will be vital in the wake of the oil spill. Projects originally intended to monitor the effects of natural disasters are now going to view the effects of this human-made one.

One such project is the Intra-Americas Sea Nowcast/Forecast model, which in the last week has been used to create a 72-hour oil forecast. Jason Jolliff, a researcher at NRL, injected NASA data from MODIS into the existing ocean circulation model and was able to project the spread of the oil, using NASA data to adjust the model for each new forecast cycle.

Related Links:
› NASA Applied Sciences Program
› NASA Applied Sciences Program Gulf of Mexico Initiative
› NASA's Oil Spill Imagery
› Research Flights Take NASA Scientists Over Gulf Oil Spill
Rory Collins
NASA Langley Research Center