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dc.contributor.authorGupta, G.V.M.
dc.contributor.authorSudheesh, V.
dc.contributor.authorSudharma, K.V.
dc.contributor.authorSaravanane, N.
dc.contributor.authorDhanya, V.
dc.contributor.authorDhanya, K.R.
dc.contributor.authorLakshmi, G.
dc.contributor.authorSudhakar, M.
dc.contributor.authorNaqvi, S.W.A.
dc.date.accessioned2017-02-14T11:48:59Z
dc.date.available2017-02-14T11:48:59Z
dc.date.issued2016
dc.identifier.citationJournal of Geophysical Research (G: Biogeosciences), vol.121(1); 2016; 159-175
dc.identifier.urihttp://drs.nio.org/drs/handle/2264/5064
dc.description.abstractObservations along 10 shelf transects in 2012 near 10°N in the southeastern Arabian Sea revealed the usual warm oligotrophic conditions during the winter monsoon and upwelling of oxygen-deficient, nutrient-rich cool water during the summer monsoon (SM). By changing an oligotrophic to a nutrient-replete condition, the upwelling is the major process that regulates the biogeochemistry of this shelf. Its onset is perceptible at 100m depth between January and March. The upwelling reaches the surface layer in May and intensifies during June–July but withdraws completely and abruptly by October. Despite the nutrient injection, the primary production during SM, integrated for euphotic zone, is comparable to that during the preceding spring intermonsoon (SIM). Again, as usual, the high oxygen demand coupled with low concentration in the upwelled subsurface waters causes severe oxygen depletion below the shallow pycnocline. The oxygen concentrations/saturations of 2012 on the midshelf are similar from those of mid-1958 to early 1960, except for marginally higher values during the peak upwelling period due to relatively weak upwelling in 2012. This implies little anthropogenic influence on coastal hypoxia unlike many other coastal regions. In 2012, the inner shelf system shifted from net autotrophy in SIM to net heterotrophy in SM but on an annual basis it was net autotrophic (gross primary production to community respiration ratio, GPP/R:1.11±0.84) as organic production exceeded consumption
dc.language.isoen
dc.publisherAGU Publications
dc.rights© 2015. The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
dc.subjectChemistry and biogeochemistry
dc.subjectChemistry and biogeochemistry
dc.subjectChemistry and biogeochemistry
dc.subjectChemistry and biogeochemistry
dc.titleEvolution to decay of upwelling and associated biogeochemistry over the southeastern Arabian sea shelf
dc.typeJournal Article


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