The stratosphere-troposphere analyses of regional transport 2008 experiment

START08 combined high-altitude long-range aircraft, new chemical meteorological models to map the chemical and microphysical structure and the major transport processes in the extratropical upper troposphere (UT) and lower toposphere (LT). The straosphereis rich in ozone but extremely dry, with 5 ppmv of water vapor. The troposphere is relatively ozone poor but moist. The Stratosphere-Troposphere Analyses of Regional Transport 2008 experiment was conducted, usng the new National Science Foundation (NSF), National Center for Atmospheric Research (NCAR) Gulfstream V (GV) research aircraft, also know as the High-Performance Instrumented AIrborne Platform for Environmentla Research (HIAPER). START08 was built upon the results and experience of the START05 experimet during the initial flights of the GV aircraft. The program shared its payload and flight operations with test flights of the HIAPER Pole-to-Pole Observation of Atmospheric Tracers experiment. The program succeeded in measuring chemical distributions, variations and relationships associated with major transport processses.