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Titel |
Continuous dynamic assimilation of the inner region data in hydrodynamics modelling: optimization approach |
VerfasserIn |
F. I. Pisnitchenko, I. A. Pisnichenko, J. M. Martínez, S. A. Santos |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1023-5809
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Digitales Dokument |
URL |
Erschienen |
In: Nonlinear Processes in Geophysics ; 15, no. 6 ; Nr. 15, no. 6 (2008-11-03), S.815-829 |
Datensatznummer |
250012800
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Publikation (Nr.) |
copernicus.org/npg-15-815-2008.pdf |
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Zusammenfassung |
In meteorological and oceanological studies the classical approach for
finding the numerical solution of the regional model consists in formulating
and solving a Cauchy-Dirichlet problem. The boundary conditions are obtained
by linear interpolation of coarse-grid data provided by a global model.
Errors in boundary conditions due to interpolation may cause large deviations
from the correct regional solution. The methods developed to reduce these
errors deal with continuous dynamic assimilation of known global data
available inside the regional domain. One of the approaches of this
assimilation procedure performs a nudging of large-scale components of
regional model solution to large-scale global data components by introducing
relaxation forcing terms into the regional model equations. As a result, the
obtained solution is not a valid numerical solution to the original regional
model. Another approach is the use a four-dimensional variational data
assimilation procedure which is free from the above-mentioned shortcoming. In
this work we formulate the joint problem of finding the regional model
solution and data assimilation as a PDE-constrained optimization problem.
Three simple model examples (ODE Burgers equation, Rossby-Oboukhov equation,
Korteweg-de Vries equation) are considered in this paper. Numerical
experiments indicate that the optimization approach can significantly improve
the precision of the regional solution. |
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