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1985
Journal Article
Titel
Measurements of selected C2-C5 hydrocarbons in the background troposphere - vertical and latitudinal variations
Abstract
Meridional cross sections of the concentration of light hydrocarbons are reported. They were obtained from 20.April to 10.May, 1980, during the French research flight STRATOZ II, and cover the latitudes between 60 degrees N and 60 degrees S and the altitudes between 80 mb and 200 mb. The mixing ratios of ethane, ethene, acetylene, propane, propene, n-butane, i-butane, n-petane, and i-petane range between 2.0 and 0.02 ppb. Globally, a decrease in concentration with increasing altitude and - in most cases - with decreasing latitude is observed. In addition the 2-dimensional concentration fields show structures of different scales. In particular, isolated maxima of high concentrations are found in the upper troposphere. They point to fast vertical transport between the boundary layer and the upper troposphere. In the present case these maxima seem to be correlated with large scale meteorological systems, such as low pressure regions or the Inter Tropical Convergence Zone. It is argued tha t the NMHC provide a set of tracers well suited to the detection of fast vertical transport. (IFU)
Language
English