文章基本信息

标题：Data Assimilation Using a Hybrid Ice Flow Model
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作者：D. N. Goldberg ; O. V. Sergienko
期刊名称：The Cryosphere
印刷版ISSN：1994-0416
电子版ISSN：1994-0424
出版年度：2011
卷号：05
期号：02
页码：315-327
DOI：10.5194/tc-5-315-2011
出版社：Copernicus Publications
摘要：Hybrid models, or depth-integrated flow models that include the effect of both longitudinal stresses and vertical shearing, are becoming more prevalent in dynamical ice modeling. Under a wide range of conditions they closely approximate the well-known First Order stress balance, yet are of computationally lower dimension, and thus require less intensive resources. Concomitant with the development and use of these models is the need to perform inversions of observed data. Here, an inverse control method is extended to use a hybrid flow model as a forward model. We derive an adjoint of a hybrid model and use it for inversion of icestream basal traction from observed surface velocities. A novel aspect of the adjoint derivation is a retention of nonlinearities in Glen’s flow law. Experiments show that in some cases, including those nonlinearities is advantageous in minimization of the cost function, yielding a more efficient inversion procedure.