An old satellite recently taught scientists a new trick, according to a recent report in Science. NASA's Earth Probe Total Ozone Mapping Spectrometer (TOMS)in operation since 1978used new technologies to reveal a key difference between the smoke and smog generated during the African and Indonesian fires in 1997. Whereas the smoke actually lingered over the fires, the smogwhich is essentially low-level ozone in the atmospherespread out quickly.

"TOMS is the only satellite instrument that follows both smoke and smog, globally," said Anne Thompson of the NASA Goddard Space Flight Center. "The extreme pollution generated during the Indonesian fires was the first time we saw smoke move more slowly and in different directions from where smog moved." The scientists say these two pollution plumes took such different tacks because they were in different layers of the atmosphere. The heavier smoke particles stayed in lower layers and so were less able to travel.