Comparison of cross-tropopause transport and ozone in the upper troposphere and lower stratosphere region

摘要: Wintertime tracer transport in the atmospheric “middle world” is analyzed for five winters using three different advection methods, namely Eulerian advection, reverse domain-filling trajectory calculations, and contour with a diagnosis of filaments. In all approaches, isentropic motion assumed. The results are compared to synopses ozone derived from Measurement Ozone Water Vapor by Airbus In-Service Aircraft (MOZAIC) airborne measurement program. Tracer data cast into “reduced” space spanned equivalent latitude, potential temperature, time. this representation some anomalies MOZAIC mirrored corresponding features stratospheric mass mixing ratios. studies give similar results, suggesting that numerical diffusion only plays minor role. out stratosphere minimizes height range 340 350 K. reveal preferred regions stratosphere-troposphere exchange associated positions storm tracks. These asymmetries correlation vorticity (PV) found data. Zonal also occurrence filamentary structure simulations filamentation maximizing downstream North Atlantic track. Hemispheric- seasonal-mean activity strongly correlated discerned Lagrangian experiments. both signals winter 1997/1998 shows lowest here. A drop 1995/1996 may, however, be related introduction more advanced assimilation scheme European Centre Medium-Range Weather Forecasts (ECMWF) analysis cycle. This change may partly responsible somewhat improved PV at high latitudes after 1994/1995.