AIRS and GES DISC provide near-real-time georeferenced observations of the spill in the Gulf of Mexico
On May 4, the Atmospheric Infrared Sounder (AIRS) instrument onboard NASA's Aqua satellite acquired this image of the growing oil spill in the Gulf of Mexico caused by the Deep Water Horizon oil rig disaster. The black arrows in the image – pointing to Gulf Shores (Alabama Gulf Coast Zoo), Gulf Islands National Sea Shore (Santa Rosa Island), and the Mississippi River mouth – indicate darker streaks that are either low-wind areas, or possible locations of patches of the oil slick, or both. Even thin organic surface films at low winds can delay surface roughness inception, creating mirror-smooth surfaces. The latter will prevent sun light to scatter toward the satellite, enhancing forward reflection instead. At appropriate angles between the sun and the satellite viewing, usually within the visible sun glint zone (cloud free), this effect is seen by the satellite as darker patches and can be exploited as slicked-areas detection.
The image shown is a snapshot from a GoogleEarth screen view. Even though AIRS is not truly an imager, the Near-Real Time (NRT) processing and the developed Web Map Services at NASA/Goddard Earth Sciences Data and Information Services Center (GES DISC) make images based on AIRS visible radiances available on a global map at 3-km resolution, just a couple of hours following the satellite overpass. As soon as AIRS visible radiances become available from the NRT production, they are mapped to a global 3-km false-color map, and are served through our AIRS Web Map Server (WMS). A significant advantage of this approach is that anyone with WMS-compliant tool on their desktop computers, such as Google Earth, can easily overlay AIRS data with other layers of information, and zoom into their region of interest.