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Couvelard, Xavier; Messager, Christophe; Penven, Pierrick; Smet, Sébastien; Lattes, Philippe. |
The oceanic circulation south of Africa is characterised by a complex dynamics with a strong variability due to the presence of the Agulhas current and numerous eddies. This area of interest is also the location of several natural gas fields under seafloor which are targeted for drilling and exploitation. The complex and powerful ocean currents induces significant issues for ship operations at the surface as well as under the surface for deep sea operations. Therefore, the knowledge of the state of the currents and the ability to forecast them in a realistic manners could greatly enforce the safety of various marine operation. Following this objective, an array of HF radar systems were deployed to allow a detailed knowledge of the Agulhas currents and its... |
Tipo: Text |
Palavras-chave: 4DVAR; Agulhas current; HF radar; ROMS; Forecast. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00677/78929/81299.pdf |
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Forget, Gael; Mercier, Herle; Ferron, Bruno. |
A set of Argo profiles collected in the North Atlantic between May 2002 and April 2003 is combined with a low-resolution general circulation model (GCM) using the adjoint method. Fitting the real hydrographic observations leads to vast improvements in the model circulation., including the sea surface height and the meridional heat transport. We find striking differences in basin-scale transports compared with previous assimilation experiments that use the same GCM and a similar spatial resolution. Based on forward modeling studies, it is argued that these differences are due to different assimilation experiment durations. Over 1 year, the hydrography interpolated with the GCM from Argo profiles better represents the contemporary structures than does a... |
Tipo: Text |
Palavras-chave: General circulation model; Argo; In situ observations; 4DVAR; Data assimilation. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3920.pdf |
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Forget, Gael; Ferron, Bruno; Mercier, Herle. |
Argo is a global array of profiling floats that provides temperature (T) and salinity (S) profiles from 2000 m to the surface every ten days with a nominal spatial resolution of 3 degrees. Here we present idealized experiments where the adjoint method is used to synthesize simulated sets of Argo profiles with a general circulation model, over a one-year period, in the North Atlantic. Using a number of drifting profilers consistent with Argo deployment objectives, the simulated array permits one to identify large-scale anomalies in the hydrography and circulation, despite the presence of a simulated eddy noise of large amplitude. Model dynamics provide an objective means to distinguish eddy noise from large-scale oceanic variability, and to infer the... |
Tipo: Text |
Palavras-chave: General circulation model; Argo; Twin experiment; 4DVAR; Data assimilation. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3721.pdf |
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