Modelling ice sheet dynamics
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چکیده
This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, redistribution , reselling , loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. This paper surveys the problem of modelling the dynamics of large ice sheets. A simplified model for two-dimensional plane ice sheets is derived, and both isothermal and non-isothermal cases are considered. The model is not uniformly asymptotically valid at a divide or at a margin, and we suggest local (isothermal) analyses which give order of magnitude estimates for divide curvature and margin slope. We also give a uniformly valid description for small perturbations to an isothermal ice sheet, which decay diffusively. For the more interesting non-isothermal case, we are able to provide explicit approximate solutions for the surface profile, based on Lliboutry's heuristic boundary layer analysis, and give an approximate description of the temperature field.
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تاریخ انتشار 1991