University of Saskatchewan

September 21, 2014   


December 09, 1999

A University of Saskatchewan physics professor is part of an international science team that has developed a pollution-tracking instrument to be launched on the NASA satellite "Terra" Dec. 16.

Professor Gary Davis is a co-investigator on the 11-member team that has developed an instrument called MOPITT (Measurements of Pollution In The Troposphere) that will be aboard Terra when it's launched from the Vandenberg Air Force Base in California next week.

MOPITT is Canada's first major instrument to measure pollution of the Earth's atmosphere from space. Built by a consortium of Canadian companies including SED Systems of Saskatoon, MOPITT is the most expensive and most ambitious space science experiment ever funded by the Canadian Space Agency.

Its aim is to enhance knowledge of the lowest region of the Earth's atmosphere, known as the troposphere, information which could reveal how pollution is affecting the environment and how pollution levels are affected by human activities. The data will be used to predict the long-term effects of atmospheric pollution and evaluate the effectiveness of pollution controls worldwide.

During its five-year mission, MOPITT will continuously scan most of the planet every four days. It will measure two pollutant gases - carbon monoxide and methane -- in the bottom 10-15 kilometres of the Earth's atmosphere.

"MOPITT is making completely unprecedented measurements," said Davis, noting that there are currently few measurements of tropospheric chemicals due to the region's great variability and cloud cover. "No space experiment has ever measured these two gases on a global scale."

Methane, a greenhouse gas, is increasing in the atmosphere at a rate of about one per cent per year, but the source of this increase is not certain. Measurements of carbon monoxide will shed light on the chemical reactions that occur in the Earth's lower atmosphere as a result of human activities such as biomass burning.

"We'll be directly measuring the effects of the burning of the Amazon rain forest which releases both methane and carbon monoxide into the atmosphere," he said.

"There's a lot of carbon monoxide produced in big cities and we'll be able to measure the plume as it's carried away by the wind." NASA's Terra satellite, which will carry four other scientific measurement instruments, represents the biggest and most significant study of the Earth's environment to date. NASA, the Canadian Space Agency and the instrument teams will collaborate throughout the operation of the satellite to release new information as it is discovered, whether it relates to forest fires, pollution, polar ice cap melting, or other atmospheric changes.

The Canadian members of the research team are building a MOPITT lookalike, called MOPITT-A, which will be used to double-check the measurements made by the satellite instrument. The MOPITT-A instrument will be periodically flown on a high-altitude research aircraft directly beneath the satellite so that both instruments "see" the same surface and atmosphere.

"All experiments are capable of going wrong in various ways and producing the wrong numbers but with space experiments we have no way of checking because they're in orbit," he said. "So we validate the satellite data by comparing against independent but comparable measurements of exactly the same stuff."

The data validation program will be run from the U of S by Davis and his team. "We anticipate U of S graduate students will be involved in the processing and interpretation of data," he said.

MOPITT-A is currently being built at the University of Toronto using spare parts from MOPITT itself. "We hope to put MOPITT-A on the research aircraft for the first time in March of 2000," he said.

The major project for MOPITT-A in 2000 will be scanning southern Africa in September. Davis will be in South Africa for the take-off and landing of the research aircraft carrying MOPITT-A. He notes the aircraft, known as the ER-2, is the same design as the Cold War spy plane known as the U-2.

Davis has been involved in the MOPITT experiment since 1991. He was invited to help test the MOPITT instrument by Professor James Drummond of the U of T who heads up the international science team and who was Davis' graduate supervisor 20 years ago.

"This project is the culmination of many years of effort by many people," said Davis. "Though the international team advises on the design and will interpret the data, this is a major space experiment built and paid for by Canada. It demonstrates Canada's commitment to understanding how human activities produce changes in our atmospheric environment."

For more information, contact:

Dr. Gary Davis
Institute of Space and Atmospheric Studies
University of Saskatchewan
(306) 966-6462

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