|
A Note from the IGAC Chair: Guy Brasseur
Space Observations of Tropospheric Chemical Composition:
Is the Scientific Community Ready?
One of the major challenges for the atmospheric chemistry community in the next decade will be to retrieve, analyze and interpret new data obtained from space. After having emphasized dynamical and chemical processes in the stratosphere, primarily in relation to the ozone depletion problem, the major space agencies (NASA in the US, ESA in Europe, and NASDA in Japan) are developing an ambitious program to investigate the chemistry of the global troposphere. Observations from several NASA satellites (TOMS, SBUV, SAGE) have already provided opportunities to derive the abundance of ozone in the troposphere. GOME, a European space instrument, has given promising information on the tropospheric abundance of several compounds including nitrogen dioxide, bromine oxide and formaldehyde. After the MAPS experiment from the Space Shuttle, the IMG instrument, which flew on the Japanese ADEOS satellite, reported nearly global observations of tropospheric carbon monoxide. Additional CO measurements as well as observations of methane are soon expected from the Canadian-US MOPITT experiment as part of the NASA Earth Observing System.
Additional space experiments are currently scheduled and will provide a large amount of new data. SCIAMACHY, MIPAS and GOMOS on board the European ENVISAT Spacecraft as well as TES, HIRDLS and MLS on board EOS/CHEM, scheduled to be launched in the early 2000's, will focus on tropospheric and lower stratospheric chemical compounds. In addition, PICASSO will use a spaceborne lidar to derive the vertical distribution of atmospheric aerosols.
As large amounts of new data become available, one should ask the question: Is the community ready for the analysis and interpretation of these data? How will we maximize the scientific return of these large technological investments?
Different new approaches are necessary including the improvement of retrieval schemes and the development of advanced assimilation algorithms applied to complex interactive chemical systems. Further, the community involved in ground-based or airborne observations and the space science community will have to cooperate better and recognize the complementarity of their respective approaches. Similarly, modelers and experimenters will have to work more closely together. Finally, it is important that international organizations like IGAC and SPARC, as well as the funding agencies, recognize the new opportunities for the scientific community and that they strive to make access to the new data as easy as possible.
|
