Theoretical arguments and observations suggest that the atmospheres of Brown Dwarfs and planets are very dynamic on chemical and on physical time scales. The modelling of such substellar atmospheres has, hence, been much more demanding than initially anticipated. This Splinter1 has combined new developments in atmosphere modelling, with noval observational techniques, and new challenges arrisin...

We examine the general problem of light transport initiated by oblique illumination of a turbid medium with a collimated beam. This situation has direct relevance to the analysis of cloudy atmospheres, terrestrial surfaces, soft condensed matter, and biological tissues. We introduce a solution approach to the equation of radiative transfer that governs this problem, and develop a comprehensive ...

The aim of this work is to assess the evolution of the structural and optical properties of BixTiyOz films grown by rf magnetron sputtering upon post-deposition annealing treatments in order to obtain good quality films with large grain size, low defect density and high refractive index similar to that of single crystals. Films with thickness in the range of 220-250 nm have been successfully gr...

Reflections of megacycle-per-second radio signals by free radicals in Earth's ionosphere are observed having about the intensity predicted for induced magnetic-dipole transitions. It seems that magnetic atoms, ions, and molecules in planetary atmospheres may be detected by this method. These cbservations were made with the topside ionosonder of the Canadian satellite Alouette II.

The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-dominated atmosphere. We explore the possibilities for photosynthesis on a rocky planet with a th...

We solve the integral equation describing the propagation of light in an isothermal plane-parallel atmosphere of optical thickness τ∗, adopting a uniform thermalization parameter ǫ. The solution given by the ALI method, widely used in the field of stellar atmospheres modelling, is compared to the exact solution. Graphs are given that illustrate the accuracy of the ALI solution as a function of ...

THE IMPACT project (Fig. 1), funded by an internal research and development process at Los Alamos National Laboratory (LANL), has the goal to develop an integrated modeling system for addressing current needs in space debris and conjunction analysis for resident space objects (RSOs) in low Earth orbit (LEO). Now, almost three years into the project, we have developed an integrated solution comb...

It is argued that photochemical processes, driven by ultraviolet starlight, could lead to large deuterium fractionation for H2O and CH4 relative to H2 in the primitive solar nebula. Implications for deuterium enrichment observed in planetary atmospheres are briefly discussed.