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| Ferron, Bruno. |
| The increasing number of oceanic observations calls for the use of synthetic methods to provide consistent analyses of the oceanic variability that will support a better understanding of the underlying mechanisms. In this study, a 1/3 degrees eddy-permitting model of the North Atlantic (from 20 degrees S to 70 degrees N) is combined with a 4D-variational method to estimate the oceanic state from altimeter observations. This resolution allows a better extraction of the physical content of altimeter data since the model spatial scales are more consistent with the data than coarser assimilation exercises because of a lower error in model representativity. Several strategies for the assimilation window are tested through twin experiments carried out under the... |
| Tipo: Text |
Palavras-chave: Ocean modelling; Data assimilation; Variational method; Meso-scale; Sea surface height; Heat transport; Meridional overturning. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00044/15534/12956.pdf |
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| Lguensat, Redouane; Viet, Phi Huynh; Sun, Miao; Chen, Ge; Fenglin, Tian; Chapron, Bertrand; Fablet, Ronan. |
| From the recent developments of data-driven methods as a means to better exploit large-scale observation, simulation and reanalysis datasets for solving inverse problems, this study addresses the improvement of the reconstruction of higher-resolution Sea Level Anomaly (SLA) fields using analog strategies. This reconstruction is stated as an analog data assimilation issue, where the analog models rely on patch-based and Empirical Orthogonal Functions (EOF)-based representations to circumvent the curse of dimensionality. We implement an Observation System Simulation Experiment (OSSE) in the South China Sea. The reported results show the relevance of the proposed framework with a significant gain in terms of Root Mean Square Error (RMSE) for scales below 100... |
| Tipo: Text |
Palavras-chave: Analog data assimilation; Sea level anomaly; Sea surface height; Interpolation; Data-driven methods. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00489/60078/63402.pdf |
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| Fournier, Severine; Lee, Tong; Wang, Xiaochun; Armitage, Thomas W. K.; Wang, Ou; Fukumori, Ichiro; Kwok, Ron. |
| The changing Arctic freshwater content and distribution have significant implications for ocean circulation, climate, and water and biogeochemical cycles. The paucity of in‐situ salinity measurements in the Arctic Ocean has limited our ability to study Arctic‐Ocean freshwater variability. Although satellite‐derived sea surface height (SSH) and ocean bottom pressure (OBP) have been used together to infer depth‐integrated freshwater content changes, these measurements are limited in sampling and resolution. Motivated by the recent development of sea surface salinity (SSS) remote sensing, we explore the use of SSS as a proxy for Arctic freshwater changes. As a first step, here we conduct a proof‐of‐concept study by analyzing the output of an ocean‐ice state... |
| Tipo: Text |
Palavras-chave: Arctic; Sea surface height; Gravimetry; Sea surface salinity; Freshwater. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00630/74164/73778.pdf |
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