A wavelet approach to representing background error covariances in a limited area model
Une approche ondelette pour représenter les covariances des erreurs dues aux données de départ dans un modèle à domaine limité
Deckmyn, A. ; Berre, L.
Année de publication
2005
The use of orthogonal wavelets for the representation of background
error covariances over a limited area is studied. Each wavelet function
contains both information on position and information on scale: using a
diagonal correlation matrix in wavelet space thus gives the possibility
of representing the local variations of correlation scale. To this end, a
generalized family of orthogonal Meyer wavelets that are not restricted
to dyadic domains (i.e., powers of 2) is introduced. A three-bases
approach is used, which allows one to take advantage of the respective
properties of the spectral, wavelet, and gridpoint spaces. While the
implied local anisotropies are relatively small, the local changes in
the two-dimensional length scale are rather well represented.</div>
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