A comparison and analysis of modeled and measured O 3 profiles from the INDOEX campaign is presented. European Centre for Medium-Range Weather Forecast (ECMWF) meteorological analyses have been assimilated into the model to represent actual meteorology. The focus of this study is on two commonly observed features 5 in the O 3 profiles: mid tropospheric O 3 maxima (300–500 hPa) over the tropical...

From high latitude lidar observations, quite precise information is extracted about the temporal evolution and vertical distribution of volcanic aerosol in the high latitude lower stratosphere following the eruption of Mount Pinatubo. Irreversible mixing of lower stratospheric aerosol, to the arctic pole during early 1992, is demonstrated, as a function of potential temperature and time. This w...

Airborne Differential Absorption Lidar (DIAL) observations of tropospheric water vapour over Brazil and between Brazil and south Europe in March 2004 are compared to 1-hourly short-range forecasts of the European Centre for Medium Range Weather Forecasts (ECMWF). On three along-flight sections across the tropical and sub-tropical 5 Atlantic between 28◦ S and 37◦N humidity fields are observed wh...

[1] Two sets of sea surface temperature/sea ice changes are used to test the sensitivity of tracer transport to the pattern of warming in the doubled CO2 climate. One set (2CO2WT) has greater tropical and high latitude sea surface temperature changes than the other (2CO2), although both fall within the range of plausible response. Simulations were done both with and without interactive ozone. R...

Relative rates of temperature change between the troposphere and surface, and the mechanisms that produce these changes, have long been a contentious issue. Graversen et al., predicated upon the ERA-40 reanalysis, report polar tropospheric amplification of surface warming and attempt to explain this finding dynamically. Here we show (1) that data from satellites and weather balloons indicate th...

We present a new model for the global tropospheric chemistry of inorganic bromine (Bry) coupled to oxidant-aerosol chemistry in the GEOS-Chem chemical transport model (CTM). Sources of tropospheric Bry include debromination of sea-salt aerosol, photolysis and oxidation of short-lived bromocarbons, and transport from the stratosphere. Comparison to a GOME-2 satellite climatology of tropospheric ...

Gas mixing in a T-shape micro mixer has been simulated using the Direct Simulation Monte Carlo (DSMC) method. It is considered that the adequate mixing occurs when the mass composition of the species, CO or N2, deviates below 1 % from their equilibrium composition. The mixing coefficient is defined as the ratio of the mixing length to the main channel’s height. As the inlet Kn increases, while ...

We present airborne in-situ trace gas measurements which were performed on eight campaigns between November 2001 and July 2003 during the SPURT-project (SPURenstofftransport in der Tropopausenregion, trace gas transport in the tropopause region). The measurements on a quasi regular basis allowed an overview of the seasonal variations of the trace gas distribution in the tropopause region over E...

Abstract. A substantial portion of the moisture transport into Arctic occurs in episodic, high-amplitude events with strong impacts on Arctic's climate system components such as sea ice. This study focuses origin moist-air intrusions during winter and examines sources, pathways, their linkage to driving large-scale circulation patterns. For that purpose, 597 intrusions, defined daily intense (e...