Having outlived its projected shelf life, a Canadian Space Agency (CSA) instrument on a U.S. Earth imaging satellite now is expected to provide data on carbon monoxide (CO) emissions in the lower atmosphere until 2009.
The Measurements of Pollution in the Troposphere (MOPITT) instrument, Canada’s contribution to NASA’s Earth Observing System, flies aboard the Terra satellite, said Rejean Michaud, director of atmospheric sciences for CSA. But while the mission’s original lifespan was projected to last from 1999 to 2004, the instrument, an infrared radiometer, has performed better than expected and its mission has since been extended another five years.
The infrared radiometer, which was built by Com Dev of Cambridge, Ontario, measures the amount of carbon monoxide present in the troposphere, or the lower atmosphere, Michaud said. Scientists keep an eye on carbon monoxide — caused largely by forest fires and inefficient manufacturing processes — because of its toxic effects. Data is often combined with other observations taken from the ground or performed by aircraft and balloons.
MOPITT completes its atmospheric probing cycle every four days, according to a CSA fact sheet on the instrument. Often, MOPITT is useful for studying the aftereffects of pollution after a major event, such as the wildfires which raged in Alaska during 2004, Michaud said. After the wildfires occurred, scientists looked at MOPITT data to observe that pollution had traveled all across North America and into the Atlantic Ocean, Michaud said.
“We’ve seen biomass burnings in Africa and South America travel distances up to 10,000 kilometers,” Michaud said.
MOPITT also has practical applications being used to examine antipollution initiatives in certain parts of the world, such as vehicle emission-reduction standards, and seeing whether the efforts are paying off.
Michaud is hoping that the five-year extension of MOPITT will allow scientists to build a set of long-term observations to use when studying pollution effects.
The University of Toronto runs the program with CSA funds, which run approximately $20 0,000 a year for the effort.
While there are a number of space-based instruments which monitor trace gases in the lower atmosphere, Michaud said MOPITT is the only instrument which focuses solely on carbon monoxide.
“There are other instruments that measure a suite of gases, but with much less accuracy,” Michaud said. MOPITT’s accuracy has been measured within 10 percent, he said.
Data is processed at the National Center for Atmospheric Research by a team of approximately a dozen scientists in Boulder, Colo., according to John Gille, the U.S. principal investigator on the project. At the center, researchers have developed data reduction software responsible for processing the data and putting it in the archives. Funded by NASA, that effort costs about $1.5 million per year, Gille said.
“We tend to use the data for studies of all kinds of things,” Gille said. A recent study lasting from March 1 to May 15 looked at the long-range transport of pollutants and their effect on air quality and climate. The team used MOPITT data in conjunction with data from low-flying aircraft to look at pollution traveling over the Gulf of Mexico and over the Pacific Ocean.
Studying pollution can be a bit of a seasonal business, Gille said. Although the team looks at the effects of biomass forest burning in Southeast Asia during the spring, and will study burning in Africa and South America in the early fall, carbon monoxide amounts tend to go down in the Northern Hemisphere during the summer, Gille said.