NASA TIES EL NINO INDUCED DROUGHT TO RECORD AIR POLLUTION FROM FIRES
Scientists using NASA satellite data have found the most intense
global pollution from fires occurred during droughts caused by El
Nino. The most intense fires took place in 1997-1998 in association
with the strongest El Nino event of the 20th century.
Bryan Duncan, Randall Martin, Amanda Staudt, Rosemarie Yevich and
Jennifer Logan, from Harvard University, used data observed by NASA's
Total Ozone Mapping Spectrometer (TOMS) satellite to quantify the
amount of smoke pollution from biomass burning over 20 years.
"It's important to study biomass burning, because those fires produce
as much pollution as use of fossil fuels. Most of the pollution from
fires is produced in the tropics, while pollution from fossil fuel use
occurs in North America, Europe and Asia," Logan said. One of the
missions of NASA's Earth Science Enterprise, which partially funded
the research, is to learn how the Earth system responds to natural and
human-induced changes, such as droughts and worldwide fires caused by
El Nino. NASA's Goddard Space Flight Center, Greenbelt, Md, developed
the smoke data, the unique Aerosol Index product from the TOMS
The Harvard scientists recently published a study in the Journal of
Geophysical Research Atmospheres that describes how they combined
the Aerosol Index data from TOMS with Scanning Radiometer and Sounder
(ASTR) fire count data from the European Space Agency's European
Remote Sensing-2 satellite.
The study assessed the effects of the 1997-1998 El Nino events on
global biomass burning. They concluded biomass burning around the
world was unusually high during the 1997-1998 El Nino, greater than in
any other period between 1979 and 2000. The amount of carbon monoxide
emitted in 1997 and 1998 was about 30 percent higher than the amount
emitted from worldwide motor vehicle and fossil fuel combustion.
"We found that fires typically produce the most pollution in
Southeast Asia in March, in northern Africa in January and February,
and in southern Africa and Brazil in August and September," Logan
said. During the El Nino of 1997-1998, Indonesia, Mexico, and Central
America experienced extreme droughts, and forest fires raged out of
The smoke from the fires in Mexico and Central America was blown
northward in May 1998, worsening air-quality and reducing visibility
over much of the eastern United States. The fires in Indonesia burned
tropical forests over an area equivalent to the size of southern New
England and released enormous amounts of pollutants. The team
estimated the Indonesian fires produced about 170 million metric tons
of carbon monoxide, which equals about one-third of the carbon
monoxide annually released from fossil fuels.
Biomass burning is the combustion of both living and dead vegetation.
It includes fires generated both by lightning and human activity.
Humans are responsible for about 90 percent of biomass burning, with
only a small percentage of natural fires contributing to the total
amount of vegetation burned.
For more information about the study and images on the
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For more information about El Nino events on the Internet,
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