Andrew Molthan from NASA’s SPoRT Center emailed us recently to advise of another “Nebula achievement” from Marshall Space Flight Center. Andrew and his team have been using Nebula to process data collected from recent storm damage in the Southeastern United States. Specifically, SPoRT is helping scientists identify damage left by the April 27th storms that devastated central and northern Alabama. We wrote about SERVIR’s achievement with the installation of the Weather Research and Forecasting Model on Nebula in our December 22, 2010 blog entry.
The SPoRT Center provides unique NASA research and remote sensing capabilities to the National Weather Service and other members of the operational weather forecasting and analysis community. SPoRT has a long history of collaboration with National Weather Service (NWS) forecast offices in the Southern Region, which spans from New Mexico to the Atlantic coast. The SPoRT Center provides numerous near real-time products from MODIS aboard Terra and Aqua, other satellite imagery from its partners, and contributes several NASA-derived datasets to support regional weather forecasting applications. In this case, SPoRT is providing unique NASA observations to support forecasters in assessment of the event, in order to compare remotely sensed damage tracks against data acquired during ground surveys in the weeks following the April 27 event.
SPoRT acquired imagery from ASTER, a high resolution imaging instrument flying aboard the Terra satellite, of storm-stricken Alabama. By combining spectral channels, they obtained false color imagery of surface damage providing important clues about how the April 27th weather event impacted vegetation and the ecology. The datasets, provided to the National Weather Service through Google Earth and other decision support tools, have assisted staff meteorologists in verifying tornado path length and width in areas where rough terrain or limited road networks make other observations difficult.
Nebula contributed to SPoRT’s efforts by hosting a tiling application with large, hi-resolution images. The application was rapidly configured on the large Nebula image; tiles were created, pushed back to the local web server, and made accessible to SPoRT partners via Google Earth and other tools.
One of the represented instances, see the image at the top of this post, illustrates how the data were tiled on Nebula, made available in Google Earth, and compare to other observations. The cyan track represents the false color “damage scar” in the ASTER data, generated by the EF-4 (Enhanced Fujita scale) tornado that ripped through the core of Tuscaloosa before moving northeast and striking the Birmingham metropolitan area. Storm damage where heavily vegetated areas have been disrupted by the storm appear in a cyan color (shade of blue), similar to urban areas of Tuscaloosa. In this case, ASTER imagery from May 4th show the aftermath of the storm, seen where vegetation and other land use patterns have been disrupted. The damage track coincides with storm structures, such as the hook echo and “debris signature” apparent on Doppler radar that was available on April 27th. At a wider view (the image below), other cyan scars are apparent and correlate well with tracks estimated by the National Weather Service. Note that the shapefile used for the NWS tracks only includes a few points, whereas the official track record is more detailed and is correlated to the satellite data.
Andrew told us that Nebula was useful for a couple of reasons. He noted that their Linux machines were busy processing data from other tasks and could not be disrupted, but even if they were available, Andrew says, they would not have been as easily configurable as Nebula. Nebula gave them the chance to “play in a sandbox” where configuration testing was easy and fast, and could be used without disrupting other local systems.
