Validation of ACE-FTS v2.2 methane profiles from the upper troposphere to lower mesosphere

Methane is one of the key species. The version v2.2 data of the ACE-FTS CH₄ data have been compared to correlative satellite, balloon-borne and ground-based Fourier transform infrared remote sensing data to assess their quality.

The comparison results indicate that the accuracy of the data is within 10% in the upper troposphere -- lower stratosphere, and within 25% in the middle and higher stratosphere up to the lower mesosphere (<60 km). The observed differences are generally consistent with reported systematic uncertainties. ACE-FTS is also shown to reproduce the variability of methane in the stratosphere and lower mesosphere.