START08/satellite data comparisons and large-scale context for START08 from MLS and ACE-FTS satellite data

In support of the Stratosphere-Troposphere Analyses of Regional Transport (START08) campaigns in April, May and June 2008, ozone, water vapor, nitric acid, and carbon monoxide fields in the upper troposphere/lower stratosphere (UTLS) from the Aura Microwave Limb Sounder (MLS) were mapped and analyzed to provide global context for the START08 flights. To relate smaller-scale features seen in chemical tracers measured during specific START08 flights to meteorological situations and large-scale transport, we use information derived from the Goddard Earth Observing System-Version 5.2.0 (GEOS-5) assimilated meteorological analyses in conjunction with MLS and ACE-FTS (Atmospheric Chemistry Experiment-Fourier Transform Spectrometer) data. This allows us to compare the START08 and satellite data in relation to dynamical structures such as the tropopause and the location of upper tropospheric jets and to study the role of these dynamical features in tracer transport. Trajectory-based transport calculations initialized with MLS data are used to compare expected small-scale structure. Differences in the resolved tracer structures are discussed in the light of the sampling and resolution characteristics of the satellite and aircraft measurements. New versions of both MLS and ACE-FTS datasets (both Version 3) will be used in the comparisons.