DMS dynamics in the most oligotrophic subtropical zones of the global ocean

Type : ACL
Nature : Production scientifique
Au bénéfice du Laboratoire : Oui
Statut de publication : Publié
Année de publication : 2012
Auteurs (15) : BELVISO Sauveur MASOTTI I TAGLIABUE A BOPP Laurent BROCKMANN P FICHOT C CANIAUX Guy PRIEUR Louis RAS Josephine UITZ Julia LOISEL Hubert DESSAILLY D ALVAIN Séverine KASAMATSU N FUKUCHI M
Revue scientifique : Biogeochemistry
Volume : 110
Fascicule : 1
Pages : 215-241
DOI : 10.1007/s10533-011-9648-1
URL : <go to isi>://wos:000309227400017
Abstract : The influences of physico-chemical and biological processes on dimethylsulfide (DMS) dynamics in the most oligotrophic subtropical zones of the global ocean were investigated. As metrics for the dynamics of DMS and the so-called 'summer DMS paradox' of elevated summer concentrations when surface chlorophyll a (Chl) and particulate organic carbon (POC) levels are lowest, we used the DMS-to-Chl and DMS-to-POC ratios in the context of three independent and complementary approaches. Firstly, field observations of environmental variables (such as the solar radiation dose, phosphorus limitation of phytoplankton and bacterial growth) were used alongside discrete DMS, Chl and POC estimates extracted from global climatologies (i.e., a 'station based' approach). We then used monthly climatological data for DMS, Chl, and POC averaged over the biogeographic province wherein a given oligotrophic subtropical zone resides (i.e., a 'province based' approach). Finally we employed sensitivity experiments with a new DMS module coupled to the ocean general circulation and biogeochemistry model PISCES to examine the influence of various processes in governing DMS dynamics in oligotrophic regions (i.e., a 'model based' approach). We find that the 'station based' and 'province based' approaches yield markedly different results. Interestingly, the 'province based' approach suggests the presence of a 'summer DMS paradox' in most all of the oligotrophic regions we studied. In contrast, the 'station based' approach suggests that the 'summer DMS paradox' is only present in the Sargasso Sea and eastern Mediterranean. Overall, we found the regional differences in the absolute and relative concentrations of DMS between 5 of the most oligotrophic regions of the world's oceans were better accounted for by their nutrient dynamics (specifically phosphorus limitation) than by physical factors often invoked, e.g., the solar radiation dose. Our 'model based' experiments suggest that it is the limitation of phytoplankton/bacterial production and bacterial consumption of DMS by pervasive phosphorus limitation that is responsible for the 'summer DMS paradox'.
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Commentaire : Times Cited: 3 Si 5th International Symposium on Biological and Environmental Chemistry of DMS(P) and Related Compounds Oct 19-22, 2010 Natl Inst Oceanography (NIO), INDIA 3
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Citation :
Belviso S, Masotti I, Tagliabue A, Bopp L, Brockmann P, Fichot C, Caniaux G, Prieur L, Ras J, Uitz J, Loisel H, Dessailly D, Alvain S, Kasamatsu N, Fukuchi M (2012) DMS dynamics in the most oligotrophic subtropical zones of the global ocean. Biogeochemistry 110: 215-241 | doi: 10.1007/s10533-011-9648-1