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| Titel |
Data assimilation using a hybrid ice flow model |
| VerfasserIn |
D. N. Goldberg, O. V. Sergienko |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 5, no. 2 ; Nr. 5, no. 2 (2011-04-13), S.315-327 |
| Datensatznummer |
250002425
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| Publikation (Nr.) |
 copernicus.org/tc-5-315-2011.pdf |
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| Zusammenfassung |
| 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 ice-stream basal traction from
observed surface velocities. A novel aspect of the adjoint derivation is a
retention of non-linearities 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. |
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