Data/hora: 05/06/2024 16:24:37

Provedor de dados: 	5	
País: 	France	
Título: 	Labile Fe(II) concentrations in the Atlantic sector of the Southern Ocean along a transect from the subtropical domain to the Weddell Sea Gyre	
Autores: 	Sarthou, G.; Bucciarelli, Eva; Chever, Fanny; Hansard, S. P.; Gonzalez-davila, M.; Santana-casiano, J. M.; Planchon, F.; Speich, Sabrina.	
Data: 	2011	
Ano: 	2011	
Resumo: 	Labile Fe(II) distributions were investigated in the Sub-Tropical South Atlantic and the Southern Ocean during the BONUS-GoodHope cruise from 34 to 57 degrees S (February-March 2008). Concentrations ranged from below the detection limit (0.009 nM) to values as high as 0.125 nM. In the surface mixed layer, labile Fe(II) concentrations were always higher than the detection limit, with values higher than 0.060nM south of 47 degrees S, representing between 39% and 63% of dissolved Fe (DFe). Apparent biological production of Fe(II) was evidenced. At intermediate depth, local maxima were observed, with the highest values in the Sub-Tropical domain at around 200 m, and represented more than 70% of DFe. Remineralization processes were likely responsible for those sub-surface maxima. Below 1500 m, concentrations were close to or below the detection limit, except at two stations (at the vicinity of the Agulhas ridge and in the north of the Weddell Sea Gyre) where values remained as high as similar to 0.030-0.050 nM. Hydrothermal or sediment inputs may provide Fe(II) to these deep waters. Fe(II) half life times (t(1/2)) at 4 degrees C were measured in the upper and deep waters and ranged from 2.9 to 11.3 min, and from 10.0 to 72.3 min, respectively. Measured values compared quite well in the upper waters with theoretical values from two published models, but not in the deep waters. This may be due to the lack of knowledge for some parameters in the models and/or to organic complexation of Fe(II) that impact its oxidation rates. This study helped to considerably increase the Fe(II) data set in the Ocean and to better understand the Fe redox cycle.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	http://archimer.ifremer.fr/doc/00048/15918/13345.pdf

DOI:10.5194/bg-8-2461-2011	
Editor: 	Copernicus Gesellschaft Mbh	
Relação: 	http://archimer.ifremer.fr/doc/00048/15918/	
Formato: 	application/pdf	
Fonte: 	Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2011 , Vol. 8 , N. 9 , P. 2461-2479	
Fonte: 	Author(s) 2011. CC Attribution 3.0 License.