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The project has three elements to it: hardware, data analysis and modelling. The MOPITT instrument, on the NASA EOS Terra satellite, measures the upwelling infrared radiance. Using the technique of correlation spectroscopy discussed elsewhere, information regarding the distribution of atmospheric CO and CH 4 can be extracted. By using appropriate data analysis techniques, concentration profiles of CO will be obtained on a global basis at a reasonably high horizontal (~22km) and vertical resolution (~3km). Column amounts of methane will be derived over the sunlit side of the orbit. These profiles will then be assimilated into models to study the chemistry and dynamics of CO, CH4 and other constituents of the lower atmosphere.
The measurement of CO profiles has been identified as being of primary importance in an effort to improve our understanding of the global system. This has been recognized by the EOS Science Steering Committee - "The fate of carbon monoxide, remotely detected from space, in conjunction with a few other critical meteorological and chemical parameters, is crucial to our understanding of the chemical reaction sequences that occur in the entire troposphere and govern most of the biogeochemical trace gases" (Eos, 1987). This view is supported by the World Meteorological Organization - "Definition of trends and distributions for tropospheric CO is essential. A satellite-borne CO sensor operating for extended periods could help enormously" (WMO, 1985).
Although CH4 also plays an important role in background atmospheric chemistry, knowledge of the column distribution taken with dynamical data may lead to a better quantitative understanding of its biogeochemical cycles. Methane is increasing in the atmosphere at a rate of about 1%/year but the source of this increase is not certain. Improved knowledge of the source strengths and distributions will help to resolve this uncertainty.
The problem of understanding tropospheric chemistry is a very difficult one and requires many interacting disciplines to resolve it. Our approach is to consider the entire science system from instrument to modelling, to scientific understanding as a continuous process requiring the skills of several different sets of people. Hence our science team consists of specialists in all the major areas required.
Funding for the MOPITT instrument is provided by the Space Science Division of the Canadian Space Agency. Funding for the U.S. effort including the development of science data processing software and science data products is provided by the NASA Goddard Space Flight Center.