Satellite Analysis of Gulf Surface Oil Extents (Video)

Updated August 3, 2010. Oil has been leaking into the Gulf of Mexico since the BP Deepwater Horizon caught fire on April 20th, 2010, exploded, and sank. The subsequent oil loss is threatening the health of the Gulf and coastal ecosystems in the region. Since April 23rd, NOAA’s Satellite Analysis Branch has been using data from a variety of high resolution visible and synthetic aperture radar satellites from NOAA’s partners in Earth observations to document the latest extent of the surface oil. Satellite data used in this daily analysis includes NASA's Aqua and Terra MODIS, Canadian Space Agency's RADARSAT-1 and -2 SAR, Italian Space Agency’s COSMO-SkyMed, German Aerospace Centre’s TerraSAR-X, JAXA's ALOS, Satellite Imaging Corporation's SPOT-5, multispectral imagery from The Disaster Monitoring Constellation, and European Space Agency's ENVISAT SAR. This animation shows the daily change in the satellite analysis of surface oil extents. It should be noted that the observed extents may in some cases not reflect the actual extents due to the difficulty in identifying oil slicks from space. For instance, medium resolution visible images are taken using sunglint data, whereby the sun’s angle creates a glare off the surface of the ocean. If the glare is not wide enough, not all of the plume will be seen. Oil-like sheens from algal blooms also complicate the matter. Very high resolution visible and synthetic aperture radar satellites also have very narrow swath coverage, so a large plume or patches of oil may extend past the bounds of the sensor’s detection area. For all of these reasons, the analysts at NOAA’s Satellite Analysis Branch must use all of the data available to generate a composite over a 24 hour period. Some days, not enough data is available to generate an accurate extent estimate, so those dates are missing from this time series. In addition, these extents show only the surface oil, not the subsurface plumes.