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| Titel |
Natural isotopic composition of nitrogen in suspended particulate matter in the Bay of Bengal |
| VerfasserIn |
S. Kumar, R. Ramesh, N. B. Bhosle, S. Sardesai, M. S. Sheshshayee |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 1, no. 1 ; Nr. 1, no. 1 (2004-10-14), S.63-70 |
| Datensatznummer |
250000071
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| Publikation (Nr.) |
 copernicus.org/bg-1-63-2004.pdf |
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| Zusammenfassung |
| We present the first measurement of nitrogen isotopic composition
(δ15N) in suspended particulate matter
(SPM) of the surface Bay of Bengal (BOB) at 24 different locations during
pre- (April–May 2003) and post- (September–October 2002) monsoon seasons.
The δ15N of particulate organic nitrogen (PON) in
surface suspended matter of coastal as well as northern open BOB shows
signatures of a two end-member mixing between continental inputs and marine
sources. Dilution by the organic and detrital continental material brought
in by rivers leads to consistently lower δ15N, evident from the relationship between surface salinity
and δ15N. δ15N of surface PON of open ocean locations during both seasons, and also at
coastal locations during pre-monsoon suggest the nitrate from deeper waters
as a predominant source of nutrient for planktons. The depth profiles of
δ15N of SPM during pre-monsoon season at nine
different locations are also presented. These indicate an increase in
δ15N by a maximum of 2.8‰ between euphotic
depth and 300 m, which is lower than that observed in the eastern Indian
Ocean, indicating the role of higher sinking rates of particles ballasted by
aggregates of organic and mineral matter in BOB. |
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