Scientists released the first observations from a new, earth-orbiting monitor Thursday that provide the most complete view of the world''s air pollution, to date, as it churns through the atmosphere, crossing continents and oceans. The images were revealed at the American Geophysical Union''s spring meeting in Boston.
Launched in December, 1999, MOPITT (Measurements of Pollution in the Troposphere) tracks the air pollutant carbon monoxide from aboard NASA''s Terra spacecraft as it circles Earth from pole to pole 16 times daily.
Policy makers and scientists are using the data collected as a way to identify the major sources of air pollution and to closely track where pollution travels year round anywhere on Earth.
Researchers at the National Center for Atmospheric Research(NCAR) in Boulder, Colo., are blending the data with output from a computer model of Earth''s atmosphere to develop the world''s first global maps of long-term, lower-atmosphere pollution.
"With these new observations, we clearly see that air pollution is much more than a local problem. It''s a global issue," said John Gille, NCAR''s lead U.S. investigator. Much human-generated air pollution is produced from large fires and then travels great distances, affecting areas far from the source, he added.
The first set of MOPITT observations, generated from March to December of 2000, has captured extensive air pollution generated by the forest fires in the western United States last summer. Emissions from the burning of fossil fuels for home heating and transportation, a major source of air pollution during the wintertime in the northern hemisphere, can be seen wafting across much of the hemisphere.
The most dramatic features, however, are the immense clourds of carbon monoxide from forest and grassland fires in Africa and South America. The plumes travel rapidly across the southern hemisphere as far as Australia during the dry season.
The maps show air pollution plumes from this region traveling over the Pacific Ocean to North America, often at fairly high concentrations. While the fires are the major contributor, Gille said he suspects that, at times, industrial sources may also contribute to these events.
Although MOPITT cannot distinguish between individual industrial sources in the same city, it can map different sources that cover a few hundred square miles. The results are accurate enough to differentiate air pollution from a large metropolitan area, for example, from a major fire in a national forest.
Animations and images of the first results from MOPITT are available at www.gfc.nasa.gov/gsfc/earth/terra/co.htm.
by Melissa Martin