Measurements of atmospheric ethene by solar absorption FTIR spectrometry
Abstract. Atmospheric ethene (C2H4; ethylene) amounts have been retrieved from high-resolution solar absorption spectra measured by the JPL MkIV interferometer. Data recorded from 1985 to 2016 from a dozen ground-based sites have been analyzed. At clean-air sites such as Alaska, Sweden, New Mexico, or the mountains of California, the ethene column was always less than 1015 molec.cm−2 and therefore undetectable. In urban sites such as Pasadena, California, ethane was measurable with column amounts of 20 × 1015 molec.cm−2 observed in the 1990's. Despite the increasing population and traffic in Southern California, a factor 3 decrease in ethene column density is observed over Pasadena in the past 25 years, accompanied by a decrease in CO. This is likely due to Southern California's increasingly stringent vehicle exhaust regulations and tighter enforcement over this period.
