New research sponsored by NASA may soon help scientists do a better job
of tracking pollution plumes around the world and help provide people
more advance warning of unhealthy air.
Researchers have discovered that smoke and smog move in different ways
through the atmosphere. A series of unusual events several years ago
created a blanket of pollution over the Indian Ocean.
In the second half of 1997, smoke from Indonesian fires remained
stagnant over Southeast Asia while smog, which is tropospheric,
low-level ozone, spread more rapidly across the Indian Ocean toward
Researchers tracked the pollution using data from NASA's Earth Probe
Total Ozone Mapping Spectrometer (TOMS) satellite instrument. "TOMS is
the only satellite instrument that follows both smoke and smog,
globally," said Anne Thompson, NASA Earth Scientist at Goddard Space
Flight Center, Greenbelt, MD. "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 above image shows the pollution over Indonesia and the
Indian Ocean on October 22, 1997. White represents the aerosols (smoke)
that remained in the vicinity of the fires. Green, yellow, and red pixels represent
increasing amounts of tropospheric ozone (smog) being carried to the
west by high-altitude winds.