A linked climatology of ozone profiles and tropopause height

A new linked climatology of ozone profiles and tropopause height (TpO3) is presented. Because stratospheric and tropospheric ozone abundances are significantly different, variations in the tropopause height induce large variability in ozone in the upper troposphere and lower stratosphere (UTLS), which results in ozone climatologies with large uncertainties in this region. However, ozone profiles at a given location and over a typical climatological interval of one month, cannot be considered as simply shifted vertically according to the tropopause height. There is value therefore in calculating ozone profile statistics including information about the tropopause height.

To create the ozone-tropopause climatology, high-vertical-resolution measurements of ozone from the satellite-based Stratospheric Aerosol and Gas Experiment II and from balloon-borne ozonesondes were used. The TpO3 climatology presents ozone mixing ratio profiles on a 1 km vertical grid, according to the tropopause (or double tropopause) height, from the surface to ~60 km. The probability distribution of tropopause heights gives additional climatological information and allows transforming TpO3 to a standard climatology of zonally mean ozone profiles.

The new climatology provides a significantly improved representation of the separation between the troposphere and the stratosphere. Its benefits are reduced variability of climatologic profiles in the UTLS, partial characterization of longitudinal variability, and characterization of ozone profiles in the presence of double tropopauses.

The TpO3 climatology can be advantageous for use as a priori in satellite retrieval algorithms (as demonstrated for ozone profile retrievals from the Ozone Monitoring Instrument on board the EOS-Aura satellite) and for validating climate model simulations.