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Reverdin, Gilles; Gascard, Jean-claude; Le Cann, Bernard; Prieur, Loic; Assenbaum, Michel; Lherminier, Pascale. |
An anticyclonic mode water vortex and its environment were investigated from November 2000 to September 2001 in the northeast Atlantic (near 43.5 degrees N, 15 degrees-19 degrees W) with neutrally buoyant drifting floats, moored current meters, satellite altimetric sea surface height, and several hydrological surveys and sections. These observations reveal a coherent inner core (similar to 0 km in diameter) made of very oxygenated northeast Atlantic central waters (11 degrees-12.7 degrees C and 35.5-35.7 on the 1978 practical salinity scale) from 150 m down to about 750-m depth. The core presents high relative vorticity (up to approximately -0.5 times the Coriolis frequency f) within at least 10 km of its center, near 400-700 m. Peak velocity along the... |
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Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6357.pdf |
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Sutherland, Peter; Gascard, Jean-claude. |
Interactions between surface waves and sea ice are thought to be an important, but poorly understood, physical process in the atmosphere-ice-ocean system. In this work, airborne scanning lidar was used to observe ocean waves propagating into the marginal ice zone (MIZ). These represent the first direct spatial measurements of the surface wave field in the polar MIZ. Data were compared against two attenuation models, one based on viscous dissipation and one based on scattering. Both models were capable of reproducing the measured wave energy. The observed wavenumber dependence of attenuation was found to be consistent with viscous processes, while the spectral spreading of higher wavenumbers suggested a scattering mechanism. Both models reproduced a change... |
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Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00333/44454/44125.pdf |
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Le Cann, Bernard; Assenbaum, Michel; Gascard, Jean-claude; Reverdin, Gilles. |
Lagrangian instruments and altimetry data are used to investigate the upper ( 0 to similar to 500 m) mean and mesoscale circulations in a region of the midlatitude northeast Atlantic (36 degrees - 47 degrees N, 13 degrees - 23 degrees W), a formation and subduction area of Subpolar Mode Water. Lagrangian data were collected between September 2000 and September 2001 with isobaric subsurface floats, totaling 34.0 float years, and surface drifting buoys, totaling 27.9 buoy years. The near-surface ( 0 - 100 m) mean circulation is dominated by two weak ( similar to 5 cm/s) eastward currents which veer southward in the domain. In the 100- to 500-m-deep layer, these eastward mean currents retroflect westward and form two anticyclonic circulation cells, opened to... |
Tipo: Text |
Palavras-chave: Altimetry; Drifting buoys; Acoustic floats; Lagrangian circulation; Mesoscale eddies; Northeastern Atlantic. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-745.pdf |
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