A new study by scientists using data from NASA's QuikScat satellite has demonstrated a novel technique to quantify urban growth based on observed changes in physical infrastructure. The researchers used the technique to study the rapid urban growth in Beijing, China, finding that its physical area quadrupled between 2000 and 2009. A team led by Mark Jacobson of Stanford University, Palo Alto, California, and Son Nghiem of NASA's Jet Propulsion Laboratory, Pasadena, California, used data from QuikScat to measure the extent of infrastructure changes, such as new buildings and roads, in China's capital. They then quantified how urban growth has changed Beijing's wind patterns and pollution, using a computer model of climate and air quality developed by Jacobson.