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List of Abstracts 164P-Observations 2.3 ID:4575 10:30The Asian UTLS – a characterization by a combined model-observation approachHella Riede 1 , Patrick Jöckel 2 , Rolf Sander 1 , Jos Lelieveld 1 , Ralph Lehmann 3 , Heini Wernli 4 , Carl A.M.Brenninkmeijer 1 , The Caribic Team 51 Max Planck Institute for Chemistry, Mainz, Germany2 DLR, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany3 Alfred Wegener Institute for Polar and Marine Research, Potsdam, Germany4 ETH, Institute for Atmospheric and Climate Science, Zurich, Switzerland5 CARIBIC projectContact: hella.riede@mpic.deIn-situ observations of atmospheric compounds are often by nature local, and limited in time and by thenumber of measured species. From this fact arises the motivation to complement such observations withthree-dimensional information based on models, which is routinely done in the form of back-trajectorycalculations. We extended this Lagrangian approach considerably through a unique combination ofatmospheric-chemistry models, which allows to separate and quantify transport, mixing, and chemistryprocesses along these trajectories.We employed a model hierarchy consisting of the global Eulerian atmospheric-chemistry general-circulationmodel EMAC and the corresponding trajectory-box model CAABA to study the characteristics of air massesin the upper troposphere / lower stratosphere (UTLS) above Asia. Model output has been compared tomonthly in-situ airborne measurements of long- and short-lived tracers from the CARIBIC project during theyears 2006 and 2007. For this purpose, chemical mixing ratios along the flight tracks have been recorded onlineduring a model simulation, which included a full atmospheric-chemistry mechanism, transient biomassburning emissions, and nudging towards ECMWF meteorology. Besides the direct comparison of tracers inthe UTLS, trajectory clusters based on ECMWF operational analysis data and on the global model have beenevaluated for further interpretation of observation-model comparisons.New and unique Lagrangian model diagnostics within the model hierarchy enable the separation andquantification of transport, mixing, and chemistry contributions of various chemical tracers on their way intothe Asian UTLS. Thus, important areas of air mass convergence and mixing are identified as well asdominant chemical reactions during the transport, and corresponding chemical lifetimes. Especially the latteranalysis reveals important variation in lifetimes - and thus in transport budgets towards the UTLS – withrespect to the trajectory source regions and emissions. In this way, the airborne observations above Asia arecomplemented with a 3-D dynamical and chemical history of the observed air masses.P-Observations 2.4 ID:4583 10:30Solar remote sensing FTIR measurements of trace gases in the marine boundary layerMartin Henchion, Nick Jones, Dave Griffith, Clare Murphyuniversity of wollongongContact: mh445@uow.edu.auMeasurements of Carbonyl Sulfide and other trace gases in the marine boundary layer have been made bySolar remote sensing Fourier transform spectroscopy. Spectra were recorded from the University ofWollongong, Australia (34.5°S, 150°E, 20m above sea level) in September and October 2009 and March2010 at very high solar zenith angles at dawn. The use of spectra recorded at dawn with the sun rising overthe Tasman Sea greatly increases the pathlength and thereby increases the sensitivity of the measurements ofmany marine boundary layer species. Here we present some initial results from these measurements for aiCACGP-IGAC 2010 14 July, 2010