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| Marchal, Olivier; Waelbroeck, Claire; Colin De Verdiere, Alain. |
| Three sediment records of sea surface temperature (SST) are analyzed that originate from distant locations in the North Atlantic, have centennial-to-multicentennial resolution, are based on the same reconstruction method and chronological assumptions, and span the past 15 000 yr. Using recursive least squares techniques, an estimate of the time-dependent North Atlantic SST field over the last 15 kyr is sought that is consistent with both the SST records and a surface ocean circulation model, given estimates of their respective error (co)variances. Under the authors' assumptions about data and model errors, it is found that the 10 degrees C mixed layer isotherm, which approximately traces the modern Subpolar Front, would have moved by ~15 degrees of... |
| Tipo: Text |
Palavras-chave: Inverse methods; Kalman filters; Climate variability; Circulation/ Dynamics; Geographic location/entity; Oceanic variability; Variability; Mathematical and statistical techniques; Fronts; North Atlantic Ocean. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00318/42922/42423.pdf |
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| Gourrion, Jerome; Szekely, Tanguy; Killick, Rachel; Owens, Breck; Reverdin, Gilles; Chapron, Bertrand. |
| Realistic ocean state prediction and its validation rely on the availability of high quality in situ observations. To detect data errors, adequate quality check procedures must be designed. This paper presents procedures that take advantage of the ever-growing observation databases that provide climatological knowledge of the ocean variability in the neighborhood of an observation location. Local validity intervals are used to estimate binarily whether the observed values are considered as good or erroneous. Whereas a classical approach estimates validity bounds from first- and second-order moments of the climatological parameter distribution, that is, mean and variance, this work proposes to infer them directly from minimum and maximum observed values.... |
| Tipo: Text |
Palavras-chave: Ocean; Climatology; Salinity; Temperature; Data quality control; Oceanic variability. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00628/74031/73359.pdf |
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| Qiu, Bo; Chen, Shuiming; Klein, Patrice; Ubelmann, Clement; Fu, Lee-lueng; Sasaki, Hideharu. |
| Utilizing the framework of effective surface quasi-geostrophic (eSQG) theory, we explored the potential of reconstructing the 3D upper ocean circulation structures, including the balanced vertical velocity (w) field, from high-resolution sea surface height (SSH) data of the planned SWOT satellite mission. Specifically, we utilized the 1/30°, submesoscale-resolving, OFES model output and subjected it through the SWOT simulator that generates the along-swath SSH data with expected measurement errors. Focusing on the Kuroshio Extension region in the North Pacific where regional Rossby numbers range from 0.22 to 0.32, we found that the eSQG dynamics constitutes an effective framework for reconstructing the 3D upper ocean circulation field. Using the modeled... |
| Tipo: Text |
Palavras-chave: Variability; Models and modeling; General circulation models; Vertical motion; Circulation/ Dynamics; Quasigeostrophic models; Mesoscale processes; Observational techniques and algorithms; Oceanic variability; Altimetry. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00309/42032/41331.pdf |
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| Drushka, Kyla; Asher, William E.; Sprintall, Janet; Gille, Sarah T.; Hoang, Clifford. |
| Surface salinity variability on O(1-10) km lateral scales (the submesoscale) generates density variability and thus has implications for submesoscale dynamics. Satellite salinity measurements represent a spatial average over horizontal scales of approximately 40-100 km but are compared to point measurements for validation, so submesoscale salinity variability also complicates validation of satellite salinities. Here, we combine several databases of historical thermosalinograph (TSG) measurements made from ships to globally characterize surface submesoscale salinity, temperature, and density variability. In river plumes; regions affected by ice melt or upwelling; and the Gulf Stream, South Atlantic, and Agulhas Currents, submesoscale surface salinity... |
| Tipo: Text |
Palavras-chave: Small scale processes; Freshwater; Fronts; Sea surface temperature; Oceanic variability. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00676/78805/81042.pdf |
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| Gasparin, Florent; Hamon, Mathieu; Rémy, Elisabeth; Le Traon, Pierre-yves. |
| Global ocean sampling with autonomous floats going to 4,000 m/6,000 m, known as the deep Argo array, constitutes one of the next challenges for tracking climate change. The question here is how such global deep array will impact on ocean reanalyses. Based on the different behavior of four ocean reanalyses, we first identified that large uncertainty exist in current reanalyses in representing local heat and freshwater fluxes in the deep ocean (1 W/m2 and 10 cm/yr regionally). Additionally, temperature and salinity comparison with deep Argo observations demonstrates that reanalysis error in the deep ocean are of the same size, or even stronger, than the deep ocean signal. An experimental approach, using the 1/4◦ GLORYS2V4 system, is then presented to... |
| Tipo: Text |
Palavras-chave: Ocean; Thermocline circulation; Bottom currents; Bottom water; In situ oceanic observations; Reanalysis data; Oceanic variability. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00515/62647/67023.pdf |
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