The temporal trend of stratospheric carbonyl sulfide

Using a database of spectra collected with an airborne infrared spectrometer between 1978 and 2005, the longest record of this type, we have searched for a temporal trend in the stratospheric OCS amount. The total column above 200 hPa, in latitudes from 30° to 60°N, shows a change of about 0.77 ± 0.80% per year relative to the 2010 value which is 1.34 × 10 15 molecules cm −2 ; thus not a significant change. Observations are made from the base of the stratosphere and are uniquely suited to determining the stratospheric OCS abundance.