Parameter Estimation Solving a Weak Constraint Variational Formulation for an Ekman Model

TittelParameter Estimation Solving a Weak Constraint Variational Formulation for an Ekman Model
PublikasjonstypeJournal Article
Utgivelseår1997
ForfattereEknes, M, Evensen, G
TidsskriftJournal of Geophysical Research: oceans
Volum102
AntallC6
Antall sider12479-12491
Utgivelsedato15/06/1997
UtgiverAmerican Geophysical Union
ISSN0148-0227
NøkkelordData assimilation, Oceanography
Sammendrag

A weak constraint variational formulation is used for inverse calculations and parameter estimation in a one-dimensional Ekman model. When parameters in the model are allowed to contain errors, the inverse problem becomes nonlinear even if the model itself is linear. It is shown that a convergent iteration can be defined for the nonlinear system of Euler-Lagrange equations and that improved estimates of the poorly known parameters can be calculated by solving the inverse problem for each of the linear iterates using the representer method. The formulation of the variational problem and the solution methods are illustrated using a simple example. The use of a simple dynamical model makes it possible to give an instructive presentation of the representer method. The method is finally used in an example using real current meter data. It is shown that the weak constraint formulation results in smooth solutions in good agreement with the data all through the water column and that it is superior to the traditional strong constraint inverse estimate.

URLhttp://www.agu.org/pubs/crossref/1997/96JC03454.shtml
DOI10.1029/96JC03454
Refereed DesignationRefereed
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