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This picture shows the seasonal average concentrations of w:tropospheric ozone in w:Dobson units over the period 1979 to 2000. In June to August photochemical ozone production causes very high concentrations over the East Coast of the USA and China. These measurements were made using data from TOMS (Total Ozone Mapping Spectrometer) and SBUV (Solar Backscatter Ultraviolet) w:satellite instruments. For more information see Tropospheric Ozone Residual (TOR) Homepage

If aforementioned link is not working, see [2]

Fishman, J., A.E. Wozniak, and J.K. Creilson, Global distribution of tropospheric ozone from satellite measurements using the empirically corrected tropospheric ozone residual technique: Identification of the regional aspects of air pollution, Atmos. Chem. Phys., 3, 893-907, 2003.[3]

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