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dc.contributor.authorNair, T.M.B.
dc.contributor.authorIttekkot, V.
dc.contributor.authorShankar, R.
dc.contributor.authorGuptha, M.V.S.
dc.date.accessioned2008-02-22T05:31:31Z
dc.date.available2008-02-22T05:31:31Z
dc.date.issued2005
dc.identifier.citationDeep-sea research. Part II. Topical studies in oceanography, Vol.52; 1930-1946p.
dc.identifier.urihttp://drs.nio.org/drs/handle/2264/985
dc.description.abstractTime series measurement of biogenic and barium fluxes was made using nine sediment traps deployed in the western, central and eastern part of the Arabian Sea with the objective of evaluating barium as a proxy for surface ocean productivity. Our observations show a strong linear correlation between Ba sub(excess) fluxes and biogenic opal and organic carbon (C sub(org)) fluxes, indicating a biogenic origin of particulate Ba. However, the correlation between biogenic and Ba sub(excess) fluxes is remarkably strong in areas of uniform productivity like the central Arabian Sea, when compared to regions of episodic productivity. The processes that precipitate particulate Ba appear to be less active during periods of high biogenic flux. A large discrepancy is documented between the export flux calculated from the barium-based algorithm and from C sub(org) fluxes at different depths. However, approx. 35% increase in Ba fluxes and a concomitant increase in Ba/C sub(org) ratios are documented between 919 and 2002 m water depth in the western Arabian Sea. This increase may be due either to barite formation within the fecal pellets of mesozooplankton thriving at deeper levels or to scavenging of Ba by Mn oxyhydroxides. Manganese oxyhydroxides seem to act as a prominent scavenging phase for particulate Ba when the Mn sub(excess) content in the settling particles exceeds approx. 200 ppm, especially in the western and central Arabian Sea where in situ precipitation of Mn oxides is reported. The estimated preservation efficiency of Ba in the Arabian Sea sediments ranges between 50% and 61%. This is two-fold higher than the global average, suggesting that Ba may be a promising proxy for paleoproductivity estimation.
dc.language.isoen
dc.publisherElsevier
dc.rightsCopyright [2005]. It is tried to respect the rights of the copyright holders to the best of the knowledge. If it is brought to our notice by copyright holder that the rights are voilated then the item would be withdrawn.
dc.subjectbiogeochemical cycle
dc.subjectbarium
dc.subjectprimary production
dc.subjecttime series analysis
dc.subjectorganic carbon
dc.subjectcorrelation
dc.titleSettling barium fluxes in the Arabian Sea: Critical evaluation of relationship with export production
dc.typeJournal Article


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