ANGEO Annales Geophysicae ANGEO 1432-0576 Copernicus GmbH Göttingen, Germany 10.5194/angeo-27-511-2009 Numerical simulation of bore generation and morphology in thermal and Doppler ducts Laughman B. 1 Fritts D. C. 1 Werne J. 1 NorthWest Research Associates, CoRA Division, Boulder, CO, USA 02 02 2009 27 2 511 523 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.ann-geophys.net/27/511/2009/angeo-27-511-2009.html The full text article is available as a PDF file from http://www.ann-geophys.net/27/511/2009/angeo-27-511-2009.pdf

We perform a series of numerical simulations employing a model describing nonlinear incompressible dynamics to explore bore generation and morphology for several ducting geometries. These include idealized thermal ducts in close proximity to, and more remote from, reflecting boundaries, an idealized Doppler duct remote from boundaries, and a combination of thermal and Doppler ducts at nearby altitudes. Based on observed bore environments, we assume initial long-wave perturbations having sinusoidal form and large amplitudes. Results indicate that close proximity of a duct to reflecting boundaries enhances bore development, that both thermal and Doppler ducts support bore development for long-wave perturbations of sufficiently large amplitudes, and that bore structures and evolutions exhibit both features anticipated by idealized bore theory and departures that remain to be explored in detail.

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