Ozone variability and trends in the UTLS derived from the IAGOS- CARIBIC observatory using JETPAC

The CARIBIC (Civil  Aircraft  for  the  Regular  Investigation  of the atmosphere Based on an 
Instrumented Container) project is part of the a European research infrastructure IAGOS (In-
Service Aircraft for a Global Observing System) making regular in-situ measurements of more 
than 100 atmospheric constituents, include ozone and water vapour, on-board of an in-service 
passenger  aircraft  operated  by  Lufthansa.  The  dataset  of  the  IAGOS-CARIBIC  is  therefore 
ideally suited as a testbed for the SPARC (Stratosphere-troposphere Processes And their Role 
in Climate) activity OCTAV-UTLS (Observed Composition Trends And Variability in the Upper 
Troposphere and Lower Stratosphere). One key aspect, shown here as work in progress, is to 
develop, define and apply common metrics for the comparison of different UTLS datasets 
using a variety of meteorological coordinate systems derived from reanalysis datasets. The 
focus here is on the variability of ozone in the upper troposphere and lower stratosphere 
(UTLS) on interannual and seasonal timescales and the observed trends. The in-situ ozone 
measurements by IAGOS-CARIBIC are analysed relative to different tropopause definitions 
and coordinate systems. All these meteorological information applied here are produced with 
the JETPAC tool ‒ Jet and Tropopause Products for Analysis and Characterization (Manney et 
al., 2011).