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Laurenceau-cornec, Emmanuel C.; Trull, Thomas W.; Davies, Diana M.; De La Rocha, Christina L.; Blain, Stephane. |
During the second KErguelen Ocean and Plateau compared Study (KEOPS2) in October-November 2011, marine snow was formed in roller tanks by physical aggregation of phytoplankton assemblages sampled at 6 stations over and downstream of the Kerguelen Plateau. Sinking velocities, morphology, bulk composition (transparent exopolymer particles, biogenic silica, particulate organic carbon), and phytoplankton contents were measured individually on 66 aggregates to identify controls on sinking velocities. Equivalent spherical diameters (ESD) ranged from 1 to 12 mm, and the particle aspect ratios, Corey shape factors, and fractal dimensions (D-F1 = 1.5, D-F2 = 1.8) were close to those of smaller natural aggregates (0.2 to 1.5 mm) collected in polyacrylamide... |
Tipo: Text |
Palavras-chave: Sinking velocity Marine snow; Aggregation; Phytoplankton; Porosity. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00352/46275/46044.pdf |
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Trull, Thomas; Davies, Diana M.; Dehairs, Frank; Cavagna, Anne-julie; Lasbleiz, Marine; Laurenceau Cornec, Emmanuel C.; D'Ovidio, Francesco; Planchon, Frederic; Leblanc, Karine; Queguiner, Bernard; Blain, Stephane. |
We examined phytoplankton community responses to natural iron fertilisation at 32 sites over and downstream from the Kerguelen Plateau in the Southern Ocean during the austral spring bloom in October-November 2011. The community structure was estimated from chemical and isotopic measurements (particulate organic carbon - POC; C-13-POC; particulate nitrogen -PN; N-15-PN; and biogenic silica - BSi) on size-fractionated samples from surface waters (300, 210, 50, 20, 5, and 1 mu m fractions). Higher values of C-13-POC (vs. co-located C-13 values for dissolved inorganic carbon -DIC) were taken as indicative of faster growth rates and higher values of N-15-PN (vs. co-located N-15-NO3 source values) as indicative of greater nitrate use (rather than ammonium use,... |
Tipo: Text |
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Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00255/36642/35222.pdf |
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