MIPAS measures global CCl4 fields

Altitude-latitude cross-section of CCl₄ in July 2008 as measured by MIPAS.

For the retrieval of CCl₄ it is important to consider the interference of emissions of peroxyacetylnitrate (PAN), which is best accounted for by jointly fitting both these species. Further, line mixing in the Q-branch of CO₂, which emits in the same spectral region, has to be considered. The use of new absorption cross-sections by J. Harrison has removed the high bias of the CCl₄ retrieval. The decadal trend of MIPAS CCl₄ data shows the hemispheric asymmetry also observed with numerous other MIPAS gases and supports the hypothesis of a shift of the subtropical mixing barriers as proposed by Stiller et al. (2017).
For more information see: http://www.atmos-meas-tech-discuss.net/amt-2016-422/