[1] Recent space and airborne observations have noted tenuous cirrus near the tropopause and above deep convective anvil outflow. We use a cloud-resolving model, initialized with aircraft observations taken during the CRYSTAL-FACE experiment, to explore the effects of such cirrus layers on anvil evolution. Numerical simulations demonstrate that anvil cirrus spreads because strong absorption of ...

Air may cross the tropical tropopause either by gradual ascent or in localized episodes associated with convection. While observations demonstrate that water vapor mixing ratios of air entering the tropical stratosphere are consistent with the mean tropical tropopause temperature, they do not resolve key mechanistic questions, such as the relative contribution of gradual or episodic transport, ...

[1] We have analyzed thirteen years (1993 to 2005) of HALOE and over two years of EOS MLS observations (September 2004 to December 2006) for QBO and annual cycle trace variations in tropical H2O, HCl, ozone, N2O, CO, HF, and CH4. We use these results to develop the theory explaining both Brewer-Dobson circulation (BDC) and QBO driven fluctuations in tropical trace gases. For H2O, BDC variations...

[1] The key factors contributing to the formation and maintenance of the recently discovered extra-tropical tropopause inversion layer are presently unclear. In this study, it is shown that such a layer can form as a consequence of the turbulent dynamics of synoptic-scale baroclinic eddies alone, in the absence of explicitly parameterized, small-scale, radiative-convective processes. A simple g...

buckle folds are common traps for hydrocarbon in several contractional provinces. buckle folds form where stratified sequences rest a top salt or some other utterly weak rock as a decollemet zone in units with high competency contrasts by a compressive stress which acted along the length of the rock layers. an important parameter affecting buckle folding of a competent zone above a mobile decol...

[1] There are some interesting day versus night differences in the water vapor and carbon monoxide concentrations near the tropopause over tropical land and ocean from 4 years of EOS Microwave Limb Sounder (MLS) observations. To interpret these differences, the diurnal cycle of deep convection reaching near tropical tropopause summarized from a decade of tropical rainfall measuring mission (TRM...

The extratropical eddy momentum flux (EMF) is controlled by generation, propagation, and dissipation of large-scale eddies and is concentrated in Earth’s upper troposphere. An idealized GCM is used to investigate how this EMF structure arises. In simulations in which the poles are heated more strongly than the equator, EMF is concentrated near the surface, demonstrating that surface drag genera...

The physical processes that drive the fluctuations of the extratropical tropopause height are examined with the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis data. A composite zonal-mean heat budget analysis for the Northern Hemisphere winter shows that fluctuations in the extratropical tropopause height result not only from a warm...

A new relationship between the surface distribution of equivalent potential temperature and the potential temperature at the tropopause is proposed. Using a Gaussian approximation for the distribution of equivalent potential temperature, we argue that the tropopause potential temperature is approximately given by the mean equivalent potential temperature at the surface plus twice its standard d...

Poor reliability of radiosonde records across South Asia imposes serious challenges in understanding the structure of upper-tropospheric and lower-stratospheric (UTLS) region. The Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) mission launched in April 2006 has overcome many observational limitations inherent in conventional atmospheric sounding instruments. Th...