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May 18, 2004
NASA’s Terra Satellite Tracks
Global Pollution
Data from NASA’s Terra satellite is
adding to our understanding of how pollution
spreads around the globe. The information will
help scientists protect and understand the
Earth.
NASA funded scientists from the National
Center for Atmospheric Research (NCAR), Boulder,
Colo., will present two studies focusing on
global air pollution. Their presentations are
part of the 2004 Joint Assembly of the American
and Canadian Geophysical Unions.
David Edwards will discuss “Observations
of Carbon Monoxide and Aerosol from the Terra
Satellite: Northern Hemisphere
Variability,” on Thursday at 8:45 a.m. EDT
in room 520D of the Palais des Congrés,
Montreal. Cathy Clerbaux will discuss,
“Tracking of Pollution Plumes Using
Measurements of Pollution in the Troposphere
(MOPITT) Measurements,” at 9:30 a.m.
EDT.
Both studies used instruments on NASA’s
Terra satellite to examine trends in global
carbon monoxide (CO) and fine particulate
(aerosol) pollution. Industry and vehicles in
urban regions and fires produce these
pollutants.
Terra and other NASA Earth observing
satellites provide vital tools for monitoring
global levels, sources and destinations of CO and
other pollutants. The growing data record shows
seasonal and annual variations, clues about how
our planet may be changing. CO molecules can last
from a few weeks to several months in the
atmosphere, allowing them to travel long
distances and impact air quality far from the
point of emission.
Edwards, an NCAR researcher, used two sensors
on NASA’s Terra to track CO and aerosols
from smoke originating in Russia. The plumes were
tracked as they spread across the Pacific Ocean,
filling the Northern Hemisphere.
In late summer 2002 and spring 2003, Terra
observed big fires in western Russia and Siberia.
The fires led to a ‘dirty’ 2002/03
winter atmosphere in the Northern Hemisphere with
high amounts of CO and aerosol. Peak levels of CO
hung over the United States.
By using two complementary instruments on
Terra, Edwards was able to tell the difference
between pollutants originating from wildfires and
those from urban and industrial sources. The
MOPITT instrument provided CO data, while the
Moderate-resolution Imaging Spectroradiometer
(MODIS) instrument recorded aerosol data.
“The satellite observations showed
Russian fires have a huge impact on air quality
on a global scale,” Edwards said.
“This work helps get the message across,
that when it comes to pollution, we need to think
globally,” he added.
Work has started to see if the MOPITT
instrument can track CO pollution originating
from cities. Clerbaux, a scientist visiting NCAR
from the French National Center for Scientific
Research, points out tracking pollution from
cities is very important, since half the people
on Earth will live in urban centers by 2007.
Though MOPITT was not designed specifically to
detect pollution plumes from cities, the results
look promising. By selecting the data and
averaging it over long time periods, the
observations were made more reliable, and help
distinguish the city emissions from other distant
sources.
MOPITT data shows how wildfires in Kalimantan
on Borneo Island in Indonesia, contaminated the
air in 2002 above Jakarta, Indonesia. “The
instrument also shows how pollution gets
dispersed from cities,” Clerbaux said.
“Mexico City and Jakarta are both
surrounded by mountains. Due to topography, Terra
revealed pollution could only escape upward or
through openings in the landscape. For example,
like the area to the north for Mexico
City,” she added.
NASA’s Earth Science Enterprise is
dedicated to understanding the Earth as an
integrated system and applying Earth System
Science to improve prediction of climate,
weather, and natural hazards using the unique
vantage point of space.
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Contacts:
Gretchen Cook-Anderson
Headquarters, Washington
Phone: 202/358-0836
Krishna Ramanujan
krishna_ramanujan@ssaihq.com
NASA Goddard Space Flight Center
Phone: 607-273-2561
Anatta
anatta@ucar.edu
National Center for Atmospheric Research,
Boulder, Colo.
Phone: 303-497-8604
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Pollution Outflow from Spring 2003
Fires in Siberia
In the spring of 2003 there were large numbers
of fires in Siberia, especially in the Baikal
region. These were detected by the MODIS
instrument on the Terra satellite (top). This
graphic shows the number of fires detected during
the month of May, 2003. These fires produced
large amounts of fine carbon aerosol which spread
out over the Pacific Ocean (center). The
suspended particles, also detected by MODIS, only
last for a few days. The MOPITT instrument on the
Terra satellite measures carbon monoxide gas
(CO). CO was also produced by the fires (bottom).
This pollutant can last for over a month. The
longer lifetime allows the gas to cross the
Pacific Ocean and reduce air quality over North
America before continuing on around the globe.
Credit: David Edwards, NCAR
High-Resolution
Image
Seasonal Variation in Atmospheric CO Global Distribution
These composite images depict carbon monoxide
(CO) measurements at an altitude of 850 hPa
(hecto pascals, a unit for atmospheric pressure).
The measurements were made by the Mopitt
instrument on the Terra satellite. The plots show
the CO observations (high values are in red)
averaged over 4 years (March 2000-February 2004)
of operation, for each season. High levels of
pollution are found in both hemispheres,
essentially above urban areas due to industry,
motor vehicle traffic and domestic heating, and
over areas where biomass fires occur. These fires
are a result of wildfires, agricultural and
deforestation burning. Pollution plumes are
transported trans-boundary, affecting air quality
in regions far from industrial and vegetation
burning activity. Credit: Cathy Clerbaux,
NCAR
Fall High-Resolution Image
Spring High-Resolution Image
Summer High-Resolution Image
Winter High-Resolution Image
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