Dec. 19, 2017 — Over the course of nearly two decades, NASA’s Terra satellite has exceeded many of its expectations from the time of its launch. Blue Waters professor at the National Center for Supercomputing Applications (NCSA) at the University of Illinois, Larry Di Girolamo, who was in his first year of graduate school studying atmospheric sciences when Terra was conceived, has literally watched the Earth change before his very eyes with Terra. “Terra has transformed earth sciences. Many of the advancements in earth sciences have come from Terra,” said Di Girolamo.
Di Girolamo presented the Terra visualizations created by NCSA’s Advanced Visualization Lab, with data processed by NCSA’s Blue Waters supercomputer at the 2017 American Geophysical Union (AGU) Fall Meeting in New Orleans, Louisiana. “NASA’s Terra data archive is about 1.2 petabytes and so far spans 17 years. Long, well calibrated data records are central to studying the earth’s climate. Blue Waters is one of the only computers that can process that data on such a large scale in a timeframe suitable for scientists to interact and ask questions of the data,” said DiGirolamo, “Blue Waters gives scientists the ability to rapidly go through the data. Without the leadership system, we would be severely held back.” These visualizations will showcase the how the Terra satellite samples the Earth in a visually compelling and informative way, and how the different instruments on the Terra satellite are fused together to better document how the Earth has been changing.
Terra satellite carries five instruments that take coincident measurements of the Earth’s system and each carries out a different mission:
- Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER) produces images using infrared, red and green wavelengths of light to create detailed high resolution land maps visualizing temperature, emissivity, reflectance and elevation.
- Clouds and Earth’s Radiant Energy System (CERES) is a pair of identical CERES sensors aboard Terra that measure the Earth’s total radiation budget and provide cloud property estimates that enable scientists to quantitatively assess the role of clouds in the Earth system.
- Multi-angle Imaging Spectroradiometer (MISR) views the Earth with cameras pointed at nine different angles to determine measure the angular distribution of scattered sunlight, which is used to measure aerosol pollution over land and water, cloud structure, and surface vegetation properties. It is designed to enhance our knowledge of the lower atmosphere and to observe how the atmosphere interacts with the land and ocean biospheres.
- Measurement of Pollution in the Troposphere (MOPITT) is the first satellite sensor to use gas correlation spectroscopy to measure the emitted and reflected radiance from the Earth in three spectral bands. The data is used to measure the amount of carbon monoxide and methane in our atmosphere.
- Moderate Resolution Imaging Spectroradiometer (MODIS) makes detailed measurements from the visible to the infrared over a 2,300-km swath, allowing scientists to retrieve a wide range of properties of the Earth’s surface, atmosphere and clouds.
The Terra satellite launched on December 18, 1999 and was originally anticipated to have a lifespan of six years. But with great engineering and clever fuel usage, Terra is now estimated to continue into the 2020’s. Terra completes about 14 orbits a day, in a circular 10:30 a.m. sun-synchronous polar orbit, where every over takes 99 minutes to complete. Since the early 2000’s, Terra has played a key role in the study of air pollution. In fact, Terra was the first to study air pollution over land from space, and includes studies of the effects of air pollution on human health. “Being able to produce results quickly with Blue Waters allows scientists to look through their data and analysis quickly, raise new hypotheses based on that analysis, and re-analyze the data to test the new hypotheses,” said Di Girolamo. “That type of interaction with the data is central to the rapid advancement of Earth Science with Terra.”
The Terra satellite is approximately the size of a school bus, weighing in at 11,442 lbs. What’s on the horizon for the future of the Terra satellite as it reaches its extended years is balancing its fuel supply against the science needs. Scientists are actively weighing the benefits and risks of maintaining its current climate quality record by continuing its orbit path, or lowering its altitude to preserve fuel to extend its time in space, but would end Terra’s climate quality data record for climate trend analysis.
About the National Center for Supercomputing Applications
NCSA at the University of Illinois at Urbana-Champaign provides supercomputing and advanced digital resources for the nation’s science enterprise. At NCSA, University of Illinois faculty, staff, students, and collaborators from around the globe use advanced digital resources to address research grand challenges for the benefit of science and society. NCSA has been advancing one third of the Fortune 50® for more than 30 years by bringing industry, researchers, and students together to solve grand challenges at rapid speed and scale.
About NCSA’S Blue Waters Project
The Blue Waters petascale supercomputer is one of the most powerful supercomputers in the world, and is the fastest sustained supercomputer on a university campus. Blue Waters uses hundreds of thousands of computational cores to achieve peak performance of more than 13 quadrillion calculations per second. Blue Waters has more memory and faster data storage than any other open system in the world. Scientists and engineers across the country use the computing and data power of Blue Waters to tackle a wide range of challenges. Recent advances that were not possible without these resources include computationally designing the first set of antibody prototypes to detect the Ebola virus, simulating the HIV capsid, visualizing the formation of the first galaxies and exploding stars, and understanding how the layout of a city can impact supercell thunderstorms.