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The primary goal of the Stratospheric Tracers of Atmospheric Transport (STRAT) campaign is the measurement of the morphology of long-lived tracers and dynamical quantities as functions of altitude, latitude, and season in order to help determine rates for global-scale transport and future distributions of high-speed civil transport (HSCT) exhaust emitted into the lower stratosphere. The observations will also improve understanding of broader issues involving transport of gases and aerosols in the stratosphere. STRAT is being sponsored by NASA's Atmospheric Effects of Aviation Project (AEAP), Upper Atmosphere Research Program (UARP), and Atmospheric Chemistry Modeling and Analysis Program (ACMAP).

Results from recent airborne campaigns (the Airborne Antarctic Ozone Expedition (AAOE); the first and second Airborne Arctic Stratospheric Expeditions (AASE I and II); the Stratospheric Photochemistry, Aerosols, and Dynamics Expedition (SPADE); and the Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft (ASHOE/MAESA)) demonstrate the capability for studies of appropriate combinations of tracers to define atmospheric transport rates for time scales from days to years, and to provide critical tests for atmospheric models used to predict impacts of future fleet emissions.

A secondary goal of STRAT is the further characterization of atmospheric photochemistry. As shown in earlier airborne campaigns, measurement of free radicals within the context of a sufficiently large suite of tracer observations provides stringent tests of our understanding of the processes that control ozone photochemistry. The STRAT campaign will extend the regions and seasons for which we have such measurements.