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dc.contributor.authorKao, Shuh-Ji
dc.contributor.authorYang, Jin-Yu Terence
dc.contributor.authorLiu, Kon-Kee
dc.contributor.authorDai, Minhan
dc.contributor.author戴民汉
dc.contributor.authorChou, Wen-Chen
dc.contributor.authorLin, Hui-Ling
dc.contributor.authorRen, Haojia
dc.date.accessioned2013-03-22T01:09:10Z
dc.date.available2013-03-22T01:09:10Z
dc.date.issued2012-06-14
dc.identifier.citationGLOBAL BIOGEOCHEMICAL CYCLES,2012,26zh_CN
dc.identifier.issn0886-6236
dc.identifier.urihttp://dx.doi.org/10.1029/2011GB004091
dc.identifier.uriWOS:000305383100001
dc.identifier.urihttps://dspace.xmu.edu.cn/handle/2288/15265
dc.description.abstractParticulate nitrogen (PN) dynamics in the oligotrophic northern South China Sea (around the SouthEast Asian Time-series Study (SEATS) station) was explored by examining the isotopic compositions of suspended PN in the top 200 m over 3 years and sinking PN collected by sediment traps. The PN inventory (IPN) in the upper 100 m is larger than in the lower 100 m, exhibiting stronger seasonality. Both layers reveal significant seasonality in mean delta N-15(PN), yet, the mean in the upper 100 m (2.0 to 5.3 parts per thousand) is consistently smaller than that in the lower 100 m, implying the occurrence of vertical biological fractionation and/or an addition of N-15-depleted N from the atmosphere. The delta N-15(PN) surges in winter, when the mixed layer is deeper, indicate an intensified nitrate supply from thermocline, during which relatively stronger downward transfer efficiency was inferred by a small IPN gradient. The largest vertical gradient in IPN appeared during intermonsoon periods, corresponding with weak vertical mixing, low delta N-15(PN), and high N* values. N fixation is likely the cause for the intermonsoon delta N-15(PN) lows. The delta N-15(PN) values of trapped material at 374 m and 447 m range from 3.3 to 7.3 parts per thousand with a flux-weighted mean of 5.6 parts per thousand resembling the delta(NO3)-N-15 of upwelled sources. By using a mass-isotope balance model under the assumption of no atmospheric N deposition, we obtained an N fixation input of similar to 20 +/- 26 mmol N m(-2) yr(-1). This value accounts for only similar to 5-10% of the new production on an annual basis.zh_CN
dc.description.sponsorshipTaiwan [NSC 98-2116-M-001-005]; Academia Sinica Thematic Program AFOBi; China (973 Program) [2009CB421200]; Introducing Talents of Discipline to Universities [B07034]zh_CN
dc.language.isoenzh_CN
dc.publisherAMER GEOPHYSICAL UNIONzh_CN
dc.subjectN-2 FIXATIONzh_CN
dc.subjectPACIFIC-OCEANzh_CN
dc.subjectCYANOBACTERIUM TRICHODESMIUMzh_CN
dc.subjectMARINE CYANOBACTERIUMzh_CN
dc.subjectSINKING PARTICLES;zh_CN
dc.subjectSTABLE NITROGENzh_CN
dc.subjectORGANIC-MATTERzh_CN
dc.subjectTIME-SERIESzh_CN
dc.subjectNITRATEzh_CN
dc.subjectCARBONzh_CN
dc.titleIsotope constraints on particulate nitrogen source and dynamics in the upper water column of the oligotrophic South China Seazh_CN
dc.typeArticlezh_CN


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