David E. Steitz
Headquarters, Washington, DC
(Phone: 202/358-1730)
Lynn Chandler
Goddard Space Flight Center, Greenbelt, MD
(Phone: 301/614-5562)
Anatta
NCAR Media Relations/UCAR Communications, Boulder, CO
(Phone: 303/497-8604)
RELEASE: 01-102
The most complete view ever assembled of the world’s air
pollution churning through the atmosphere, crossing
continents and oceans, has been produced by NASA’s Terra
spacecraft. For the first time, policymakers and scientists
now have a way to identify the major sources of air pollution
and can closely track where the pollution goes, anywhere on
Earth.
The new global air pollution monitor onboard Terra is the
innovative Measurements of Pollution in the Troposphere, or
MOPITT experiment, which was contributed to the Terra mission
by the Canadian Space Agency. The instrument was developed by
Canadian scientists at the University of Toronto and built by
COM DEV International of Cambridge, Ontario. The data was
processed by a team at the U.S. National Center for
Atmospheric Research (NCAR). MOPITT is making the first long-
term global observations of the air pollutant carbon monoxide
as Terra circles the Earth from pole to pole, 16 times every
day.
“With these new observations you clearly see that air
pollution is much more than a local problem. It’s a global
issue,” said John Gille, MOPITT principal investigator at
NCAR in Boulder, CO. “Much of the air pollution that humans
generate comes from natural sources such as large fires that
travel great distances and affects areas far from the
source.”
The first MOPITT observations are being released at the
annual American Geophysical Union spring meeting in Boston,
MA.
The most dramatic features, taken from last year from March
to December, are the immense clouds of carbon monoxide from
grassland and forest fires in Africa and South America. The
plumes slowly travel across the Southern Hemisphere as far as
Australia during the dry season in this part of the world.
Gille was surprised to discover a strong source of carbon
monoxide in Southeast Asia. The air pollution plume from this
region moves over the Pacific Ocean and reaches North
America, frequently at fairly high concentrations, according
to Gille. While fires are the major contributor to these
carbon monoxide plumes, he suspects, at times, industrial
sources may also be a factor.
“The MOPITT observations represent a powerful new tool for
identifying and quantifying pollution sources and for
observing the transport of pollution on international and
global scales,” said atmospheric chemist Daniel J. Jacob,
Harvard University, Cambridge, MA, who used MOPITT data this
spring in a major field campaign to study air pollution from
Asia. “Such information will help us improve our
understanding of the linkages between air pollution and
global environmental change, and it will likely play a
pivotal role in the development of international
environmental policy.”
MOPITT also captured the extensive air pollution generated by
the forest fires in the western United States last summer. A
major source of air pollution during the wintertime in the
Northern Hemisphere is the burning of fossils fuels for home
heating and transportation, which can be seen wafting across
much of hemisphere.
Although MOPITT cannot distinguish between individual
industrial sources in the same city, it can map different
sources that cover a few hundred square miles. This is
accurate enough to differentiate air pollution from a major
metropolitan area, for example, from a major fire in a
national forest. About half of the global emissions of
carbon monoxide are caused by human activities.
Carbon monoxide is not only a hazardous air pollutant itself,
it is also a chemical compound that produces ozone, a
greenhouse gas that is a human health hazard. MOPITT sees
carbon monoxide in the atmosphere from 2 to 3 miles above the
surface, where it interacts with other gases and forms ozone.
This pollutant can move upward to altitudes where it can be
blown rapidly for great distances or it can move downward to
the surface.
Carbon monoxide is a byproduct of the incomplete burning of
fossil fuels by cars, industry, and home heating and the
burning of natural organic matter such as wood. By tracking
plumes of carbon monoxide, scientists are able to track the
movements of other pollutants such as nitrogen oxides that
are also produced by the same combustion processes but cannot
be directly detected from space.
Animations and images of the first results from MOPITT are
available at:
http://www.gsfc.nasa.gov/gsfc/earth/terra/co.htm