Research Flights Take NASA Scientists Over Gulf Oil Spill
A team from NASA's Langley Research Center in Hampton, VA, made research
flights over the Gulf of Mexico this week to help investigate potential uses
of satellites for monitoring the thickness and dispersal of oil spills and
the oil¹s impact on marine life.
The flights were part of a NASA-wide mobilization of its remote-sensing
assets to help assess and research the spread and impact of the Deepwater
Horizon BP oil spill. Langley's King Air B-200, outfitted with two sensing
instruments, flew Monday and Tuesday over the oil slick created by the
explosion of a drilling rig nearly three weeks ago.
Data gathered during the flights will underpin a new effort to use satellite
data to enhance monitoring and detection of oil spills. Other measurements
taken during the flights could be used to observe the ecological impact of
the oil spill by observing the density of phytoplankton – critical in the
marine food chain – in Gulf waters.
The B-200 flew both the High Spectral Resolution Lidar (HSRL), from NASA
Langley (Chris Hostetler, principal investigator) and the Research Scanning
Polarimeter (RSP), from NASA's Goddard Institute for Space Studies in New
York (Brian Cairns, principal investigator). NASA atmospheric scientists
have often flown the two instruments together to better understand the
climate impact of clouds and aerosols – man-made and natural airborne
particles such as pollution or dust. The instruments were designed to study
the atmosphere, but were flown over the Gulf in an experimental capacity to
see if their measurements could help verify whether similar NASA satellite
instruments in space could be used to monitor oil spills and the biology of
The HSRL emits pulses of laser light through the atmosphere and then
captures how aerosols and clouds scatter or absorb the light. These
observations provide scientists with information about the amount and type
of particles in the air. The RSP measures polarized light to get a more
accurate reading of aerosols' reflective and absorptive properties. These
observations are complementary to the HSRL's, which improves the value of
both instruments. During this week's flights, instead of measuring how
particles in the air affect the lidar's laser light, scientists were looking
at how the lidar's beam reflected off the surface of the water and particles
below the surface.
When the lidar hits an oil patch, it will reflect in a different way than it
does over open water. The way the sun and laser light reflect off the ocean
surface may tell scientists how thick and dense the oil is. Likewise,
scientists believe the lidar backscatter can determine the density of
phytoplankton near the surface, said Yongxiang Hu, a Langley research
scientist working on the project.
"One of the things we really want to do is look at the biological changes,"
For both observing phytoplankton and the properties of the oil spill, the
HSRL flight is ultimately a verification method for the similar lidar
instrument on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite
Observations (CALIPSO) satellite. CALIPSO will provide a steady stream of
data to scientists. Its orbit has already taken it over the Gulf at least 16
times since the oil spill. Plus, CALIPSO's previous three-plus years of
operation could provide a strong baseline of measurements for comparison.
Scientists are still conducting research to determine the quality of that
data for ocean-observing purposes.
Both of these research efforts are being explored through a two-year project
competitively funded by the NASA Applied Sciences Program's Gulf of Mexico
Initiative, with Sonia Gallegos of the Naval Research Laboratory as
principal investigator. In collaboration with NRL and NOAA, NASA Langley
scientists are attempting to create a spaceborne monitoring system to detect
and measure oil spills in the future, particularly in the Gulf. The system
would combine the measurements of a suite of NASA satellite instruments. The
two-year project also aims to develop a capability to observe changes in
phytoplankton, which could be a key indicator of the health of all marine
life in the Gulf.
NASA Earth Science Division's Applied Sciences Program: http://appliedsciences.nasa.gov/
NASA Applied Sciences Program Gulf of Mexico Initiative: http://www.coastal.ssc.nasa.gov/
NASA's Langley Research Center