The discovery was made by researchers analyzing four years of data collected by the Multi-angle Imaging Spectro-Radiometer (MISR) onboard the Terra satellite. Lofted into orbit on Dec. 18, 1999, Terra is the flagship of NASA's Earth Observing System Program.
"This study is the most comprehensive and detailed examination of industrial, smoke and other air pollution particles over the Indian subcontinent to date, and reveals how topography, meteorology and human activity help determine where these particles are concentrated," said Larry Di Girolamo, a professor of atmospheric sciences at the University of Illinois at Urbana-Champaign and a co-investigator on the MISR mission.
"MISR is the first instrument to make high-resolution, multi-angle radiometric measurements of Earth from space," Di Girolamo said. "By measuring reflected sunlight at nine angles, we can accurately determine the amount of particulate matter, including that generated from man-made pollution, in the atmosphere."
While high pollution levels were found over much of India, a concentrated pool of particles was discovered over Bihar, a largely rural area with a high population density. A large source contributing to the Bihar pollution pool is the inefficient burning of a variety of biofuels during cooking and other domestic use. Particles in the smoke remain close to the ground, trapped by valley walls, and unable to mix upward because of a high-pressure system that dominates the region during winter.
"The result is a pollution episode that can affect both human health and local climate," Di Girolamo said. "The airborne particles can d
Contact: James E. Kloeppel, Physical Sciences Editor
University of Illinois at Urbana-Champaign