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Awo, F. M.; Alory, G.; Da-allada, Casimir Yelognisse; Delcroix, T.; Jouanno, J.; Kestenare, E.; Baloitcha, E.. |
The characteristic sea surface salinity (SSS) patterns associated with the tropical Atlantic meridional and equatorial interannual modes are extracted from in situ observations, by a statistical analysis performed on the 1980–2012 period. These SSS signatures of the interannual climatic modes are reproduced in a regional numerical simulation. For each mode, oceanic and/or atmospheric processes driving the SSS signature are identified through a mixed‐layer salt budget in the validated model. During a positive meridional mode in spring, a northward shift of the Intertropical Convergence Zone and related precipitation maximum creates a south‐north dipole of positive‐negative SSS anomalies around the equator. Western boundary currents strengthen and advect... |
Tipo: Text |
Palavras-chave: Sea surface salinity; Tropical Atlantic; Interannual climatic modes. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00463/57517/59694.pdf |
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Zhou, M.; Zhu, Y.; D'Ovidio, F.; Park, Y.-h.; Durand, I.; Kestenare, E.; Sanial, V.; Van-beek, P.; Queguiner, B.; Carlotti, F.; Blain, S.. |
Mean currents, horizontal diffusivity and upwelling on the Kerguelen Plateau and the deep basin east of the Kerguelen Islands were studied using 48 World Ocean Circulation Experiment (WOCE) Standard Surface Velocity Program (SVP) drifters deployed during the 2011 austral spring KEOPS II (KErguelen Ocean Plateau compared Study II) cruise. These drifter data were analyzed based on autocovariances for temporal scales, least-squares fitted streamfunctions for estimating mesoscale mean currents, wind stress fields and Ekman pumping, and Taylor's single particle diffusivity for estimating horizontal dispersion of surface waters. The results have revealed the shelfbreak current on the southern and eastern shelf slopes of the Kerguelen Islands, transport of... |
Tipo: Text |
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Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00295/40621/39568.pdf |
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Sanial, V.; Van Beek, P.; Lansard, B.; Souhaut, M.; Kestenare, E.; D'Ovidio, F.; Zhou, M.; Blain, S.. |
The Southern Ocean is known to be the largest high-nutrient, low-chlorophyll (HNLC) region of the global ocean due to iron limitation. However, a large phytoplankton bloom develops annually downstream of the Kerguelen Islands, a bloom which is sustained partly by iron released from the sediments deposited onto the shelves. In the framework of the KEOPS-2 project, we used radium isotopes (Ra-224, T-1/2 = 3.66 d; Ra-223, T-1/2 = 11.4 d; Ra-228, T-1/2 = 5.75 yr) to provide information on the origin of iron fertilization and on the timescales of the transfer of sedimentderived inputs (including iron and other micronutrients) towards offshore waters. Significant Ra-224 and Ra-223 activities were found in the near vicinity of the Kerguelen Islands, in agreement... |
Tipo: Text |
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Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00291/40256/39575.pdf |
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