Comparative assimilation of Topex/Poseidon and ERS altimeter data and of TAO temperature data in the tropical Pacific ocean during 1994-1998, and the mean sea-surface height issue
Parent, L.; Testut, C.-E.; Brankart, J.-M.; Verron, J.; Brasseur, P.; Gourdeau, L. (2003). Comparative assimilation of Topex/Poseidon and ERS altimeter data and of TAO temperature data in the tropical Pacific ocean during 1994-1998, and the mean sea-surface height issue. J. Mar. Syst. 40-41: 381-401. https://dx.doi.org/10.1016/S0924-7963(03)00026-5 In: Journal of Marine Systems. Elsevier: Tokyo; Oxford; New York; Amsterdam. ISSN 0924-7963; e-ISSN 1879-1573, more Also appears in:Grégoire, M.; Brasseur, P.; Lermusiaux, P.F.J. (Ed.) (2003). The use of data assimilation in coupled hydrodynamic, ecological and bio-geo-chemical models of the ocean. Selected papers from the 33rd International Liege Colloquium on Ocean Dynamics, held in Liege, Belgium on May 7-11th, 2001. Journal of Marine Systems, 40-41. Elsevier: Amsterdam. 1-406 pp., more |  |
| Keyword | | | Author keywords | assimilation; mean sea-surface height (MSSH); Pacific Ocean; altimetry;El Nino |
| Authors | | Top | - Parent, L.
- Testut, C.-E.
- Brankart, J.-M.
| - Verron, J.
- Brasseur, P., correspondent
- Gourdeau, L.
| |
| Abstract | Five years of Topex/Poseidon (T/P) and ERS sea level anomaly (SLA) data (1994–1998) are assimilated every 10 days into a primitive equation model of the tropical Pacific ocean. The data assimilation technique used here is a reduced-order Kalman filter derived from the Singular Evolutive Extended Kalman (SEEK) filter [J. Mar. Syst. 16(3–4) (1998) 323] with an error covariance matrix parameterised by a subset of multivariate 3D global empirical orthogonal functions (EOFs). The assimilation run is compared to the free run and to independent data from the TAO network. The impact of sea-surface height (SSH) assimilation on surface and subsurface temperature and currents is estimated in the equatorial band.In a second stage, temperature data from the TAO array are assimilated in the same conditions as in the first stage. The comparison between the results of the two assimilation experiments is made mainly with a view to gaining insights into the mean sea-surface height (MSSH) for the assimilation of altimeter data, and more generally, into the question of biases. XBT observations and TAO array data are then used to build a physically more consistent mean sea-surface height for assimilation of SLA data. Results from the assimilation of altimeter data referenced to this new MSSH show significant improvements. |
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