Comparison of satellite total ozone measurements with the distribution of tropospheric ozone obtained by an airborne UV-DIAL system over the Amazon Basin

During July and August 1985, an extensive field program was conducted throughout the Amazon Basin in Brazil to characterize the chemical composition of the atmosphere in this region of the world. Using the NASA Electra aircraft, a comprehensive picture of the distribution of tropospheric ozone was obtained during this 3-week experiment. The data indicate that substantial gradients of tropospheric ozone can be present on a horizontal scale of 100 km and a vertical scale of less than 1 km. Throughout this period. the integrated amount of ozone in the lowest 3-4 km of the atmosphere more than doubled because of the photochemical reactions associated with the polutants emitted to the atmosphere as a result of widespread biomass burning that was present during the latter portions of the field experiment. This study compares this comprehensive tropospheric ozone data set with a set of satellite total ozone measurements. These comparisons indicate that the spatial and temporal variability in the total ozone satellite data is closely related to the variability in the observed distributions of tropospheric ozone, even though the troposphere contains less than 15% of the total ozone in the atmosphere. Additional data obtained from a series of ozonesonde launches and other satellite measurements confirm that the increase in total ozone amounts over this period was a result of ozone increases in the troposphere.