[1] We use kinematic and diabatic back trajectory calculations, driven by winds from a general circulation model (GCM) and two different data assimilation systems (DAS), to compute the age spectrum at three latitudes in the lower stratosphere. The age spectra are compared to chemical transport model (CTM) calculations, and the mean ages from all of these studies are compared to observations. Th...

The quasigeostrophic equations consist of the advection of linearized potential vorticity coupled with advection of temperature at the bounding upper and lower surfaces. Numerical models of quasigeostrophic flow often employ greater (scaled) resolution in the horizontal than in the vertical (the two-layer model is an extreme example). In the interior, this has the effect of suppressing interact...

The spectrum of the kinematic dynamo operator for an ideally conducting uid and the spectrum of the corresponding group acting in the space of continuous divergence free vector elds on a compact Rie-mannian manifold are described. We prove that the spectrum of the kinematic dynamo operator is exactly one vertical strip whose boundaries can be determined in terms of the Lyapunov-Oseledets expone...

Carbon monoxide and ammonia have been detected in the spectrum of Gl 229B at abundances that differ substantially from those obtained from chemical equilibrium. Vertical mixing in the atmosphere is a mechanism that can drive slowly reacting species out of chemical equilibrium. We explore the effects of vertical mixing as a function of mixing efficiency and effective temperature on the chemical ...

We demonstrate chaotic mode lasing in vertical cavity surface emitting lasers at room temperature, with an open cavity confined laterally by the native oxide layer. Instead of introducing any defect mode, we show that suppression of lower-order cavity modes can be achieved by destroying vertical reflectors with a surface microstructure. Lasing on chaotic modes is observed directly through colle...

The objectives are i) to characterize the ambient noise field coherence for the data recorded on the North Pacific Acoustic Laboratory (NPAL) and ii) to apply broadband, full field processing to characterize the sources in the local environment. Coherence measurements based upon field data are fundamental to understanding how the various sources of the ambient noise superimpose and lead to both...