A multivariate balance operator for variational ocean data assimilation.
| Title | A multivariate balance operator for variational ocean data assimilation.
|
Technical memorandum
|
|
| Date Published |
04/2006
|
| Secondary Title |
ECMWF Technical Memoranda
|
| Number |
491
|
| Author | |
| Publisher |
ECMWF
|
| Abstract | It is common in meteorological applications of variational assimilation to specify the error covariances of the model background state implicitly via a transformation from model space where variables are highly correlated to a control space where variables can be considered to be approximately uncorrelated. An important part of this transformation is a balance operator which effectively establishes the multivariate component of the error covariances. The use of this technique in ocean data assimilation is less common. This paper describes a balance operator that can be used in a variable transformation for oceanographic applications of three-and four-dimensional variational assimilation. The proposed balance operator has been implemented in an incremental variational data assimilation system for a global ocean general circulation model. Evidence that the balance operator can explain a significant percentage of background-error variance is presented. The multivariate analysis structures implied by the balance operator are illustrated using single observation experiments. |
| URL | https://www.ecmwf.int/en/elibrary/76869-multivariate-balance-operator-variational-ocean-data-assimilation |
| DOI | 10.21957/a1q77nvm8 |
| Download citation |