The strength and structure of the Brewer–Dobson circulation (BDC) are explored in an idealized general circulation model. It is shown that diabatic forcing of the stratosphere and planetary wave forcing by the troposphere can have comparable effects on tracer transport through the stratosphere, as quantified by the mean age of air and age spectrum. Their impact, however, is mediated through dif...

Leaky trapped mountain lee waves are investigated by examining the structure of individual linear modes in multilayer atmospheres. When the static stability and cross-mountain wind speed are constant in the topmost unbounded layer, modes that decay exponentially downstream also grow exponentially with height. This growth with height occurs because packets containing relatively large amplitude w...

Using NCEP–NCAR reanalysis data, decadal trends in planetary wave activity in Northern Hemisphere high latitudes (508–908N) in late winter and early spring (January–February–March) were studied. Results show that wave activity in both the stratosphere and the troposphere has been largely reduced and exhibits statistically significant downward trends since the 1980s. In the stratosphere, the wav...

GPS radio occultation (RO) is characterized by high accuracy and excellent height resolution, which has great advantages in analyzing atmospheric structures including small-scale vertical fluctuations. The vertical resolution of the geometrical optics (GO) method in the stratosphere is about 1.5 km due to Fresnel radius limitations, but full spectrum inversion (FSI) can provide superior resolut...

Using NCEP–NCAR 51-yr reanalysis data, the interannual and decadal variations of planetary wave activity and its relationship to stratospheric cooling, and the Northern Hemisphere Annular mode (NAM), are studied. It is found that winter stratospheric polar temperature is highly correlated on a year-to-year basis with the Eliassen–Palm (E–P) wave flux from the troposphere, implying a dynamical c...

Leaky trapped mountain lee waves are investigated by examining the structure of individual linear modes in multilayer atmospheres. When the static stability and cross-mountain wind speed are constant in the topmost unbounded layer,modes that decay exponentially downstream also grow exponentially with height. This growth with height occurs because packets containing relatively large-amplitude wa...

This paper addresses various characteristic features associated with the hydration of the tropical upper troposphere and lower stratosphere (UTLS) in association with the boreal monsoonal convective activity occurring over three different tropical regions viz. Asian region, American region and African region. Analysis of water vapor mixing ratio (WVMR) data obtained from AURA MLS (v3.3), ISCCP ...

[1] A series of 24 h mesoscale simulations (of 10 km horizontal and 400 m vertical resolution) are performed to examine the characteristics and forcing of gravity waves (GWs) relative to planetary waves (PWs) during the 2008–2009 major stratospheric sudden warming (SSW). Just prior to SSW occurrence, widespread westward propagating GWs are found along the vortex’s edge and associated predominan...