In the past, studies of stratosphere-troposphere exchange of mass and chemical species have mainly emphasized the synopticand small-scale mechanisms of exchange. This review, however, includes also the global-scale aspects of exchange, such as the transport across an isentropic surface (potential temperature about 380 K) that in the tropics lies just above the tropopause, near the 100-hPa press...

[1] Global Ozone Monitoring Experiment (GOME) observations from 1997–2000 have revealed the Tibetan Middle Tropospheric Ozone Minimum (TMTOM), a lowozone layer that occurs in the middle troposphere over the Tibetan Plateau (TP) in June. Ozone profiles were derived from GOME observations and validated by ozonesonde measurements at two stations (Lhasa and Xining) over the TP. The mean bias is 5–1...

While the Voyager mission could essentially not reveal the dynamics of Titan's troposphere, useful information was obtained by the Cassini spacecraft and, particularly, by the Huygens probe that landed on Titan's surface; this information can be interpreted by means of numerical models of atmospheric circulation. The meridional circulation is likely to consist of a large Hadley circulation asym...

Experiments with the Whole Atmosphere Community Climate Model (WACCM) are used to understand the influence of the stratospheric tropical Quasi-Biennial Oscillation(QBO) in the troposphere. The zonally symmetric circulation in thermal wind balance with the QBO affects high frequency eddies throughout the extratropical troposphere. The influence of the QBO is strongest and most robust in the Nort...

Using one-dimensional thermochemical/photochemical kinetics and transport models, we examine the chemistry of nitrogen-bearing species in the Jovian troposphere in an attempt to explain the low observational upper limit for HCN. We track the dominant mechanisms for interconversion of N2-NH3 and HCN-NH3 in the deep, high-temperature troposphere and predict the rate-limiting step for the quenchin...

Two-layer equatorial primitive equations for the free troposphere in the presence of a thin atmospheric boundary layer and thermal dissipation are developed here. An asymptotic theory for the resonant nonlinear interaction of long equatorial baroclinic and barotropic Rossby waves is derived in the presence of such dissipation. In this model, a self-consistent asymptotic derivation establishes t...

During the Mediterranean Intensive Oxidant Study (MINOS) in August 2001 a total of 14 measurement flights were performed with the DLR Falcon jet aircraft from Heraklion, Crete. One objective of this campaign was to investigate the role of long-range transport of pollutants into the Mediterranean area. An analysis of 5-day back trajectories indicates that in the lower troposphere (0–4 km) air ma...

A sensitive laser spectrometer, named IRIS (water isotope ratio infrared spectrometer), was developed for the in situ detection of the isotopic composition of water vapour in the upper troposphere and the lower stratosphere. Isotope ratio measurements can be used to quantify troposphere-stratosphere exchange, and to study the water chemistry in the stratosphere. IRIS is based on the technique o...

In the earth-ocean-atmosphere system, the halogenated species take part in the cycles of several key processes involving both gas and heterogeneous interactions. The atmospheric cycles of reactive halogens are very complex specifically for those emitted from natural sources. As far as their roles in the tropospheric chemistry, the halogen compounds particularly those containing bromine (Br) and...

[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...