干旱区生态环境知识资源中心(Arid): Latitudinal variations in delta(30)Sj and delta N-15 signatures along the Peruvian shelf: quantifying the effects of nutrient utilization versus denitrification over the past 600 years

Arid

DOI	10.5194/bg-16-2163-2019
	Latitudinal variations in delta(30)Sj and delta N-15 signatures along the Peruvian shelf: quantifying the effects of nutrient utilization versus denitrification over the past 600 years
	Doering, Kristin 1,5; Ehlert, Claudia 2; Martinez, Philippe 3; Frank, Martin 1; Schneider, Ralph 4
通讯作者	Doering, Kristin
来源期刊	BIOGEOSCIENCES
ISSN	1726-4170
EISSN	1726-4189
出版年	2019
卷号	16 期号:10 页码:2163-2180
英文摘要	The stable sedimentary nitrogen isotope compositions of bulk organic matter (delta N-15(buik)) and the silicon isotope composition of diatoms (delta Si-30(Bsi)) both mainly reflect the degree of past nutrient utilization by primary producers. However, in ocean areas where anoxic and suboxic conditions prevail, the delta N-15(buik) signal ultimately recorded within the sediments is also influenced by water column denitrification, causing an increase in the subsurface delta N-15 signature of dissolved nitrate (delta(NO3)-N-15) upwelled to the surface. Such conditions are found in the oxygen minimum zone off the coast of Peru, where, at present, an increase in subsurface delta 15NO; from north to south along the shelf is observed due to ongoing denitrification within the poleward-flowing subsurface waters, while the delta Si-30 signature of silicic acid (delta Si-30(OH)(4)) at the same time remains unchanged. Here, we present three new delta(30)SiBs, records between 11 and 15 S and compare these to previously published delta Si-30(Bs), and delta N-15(bulk) records from Peru covering the past 600 years. We present a new approach to calculate past subsurface 815NO; signatures based on the direct comparison of delta Si-30(Bs), and delta N-15(bulk) signatures at a latitudinal resolution for different time periods. Our results show that, during the Current Warm Period (CWP, since 1800 CE) and prior shortterm arid events, source water delta(NO)-N-15; compositions have been close to modern values, increasing southward from 7 to 10%0 (between 11 and 15 S). In contrast, during the Little Ice Age (LIA) we calculate low delta(NO3)-N-15 values between 6 parts per thousand and 7.5 parts per thousand. Furthermore, the direct delta Si-36(Bs), versus delta N-15(bulk) comparison also enables us to relate the short-term variability in both isotope compositions to changes in the ratio of nutrients (NO3- : Si(OH)(4)) taken up by different dominating phytoplankton groups (diatoms and non-siliceous phytoplankton) under the variable climatic conditions of the past 600 years. Accordingly, we estimate a shift from a 1 : 1 (or 1 : 2) ratio during the CWP and a 2 : 1 (up to 15 : 1) ratio during the LIA, associated with a shift from overall high nutrient utilization to NO3-dominated (and thus non-siliceous phytoplankton) utilization.
类型	Article
语种	英语
国家	Germany ; France ; Canada
开放获取类型	Green Accepted, Green Submitted, gold
收录类别	SCI-E
WOS记录号	WOS:000468813800002
WOS关键词	INTERTROPICAL CONVERGENCE ZONE ; SILICON ISOTOPE FRACTIONATION ; SOUTHERN-OCEAN ; TROPICAL PACIFIC ; UPWELLING SYSTEM ; MARINE DIATOMS ; BIOGENIC OPAL ; ICE-AGE ; NITROGEN ; VARIABILITY
WOS类目	Ecology ; Geosciences, Multidisciplinary
WOS研究方向	Environmental Sciences & Ecology ; Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/214609
作者单位	1.GEOMAR Helmholtz Ctr Ocean Res Kiel, D-24148 Kiel, Germany; 2.Carl von Ossietzky Univ Oldenburg, Max Planck Res Grp, Marine Isotope Geochem, D-26129 Oldenburg, Germany; 3.Univ Bordeaux, CNRS, EPOC, UMR 5805, Pessac, France; 4.Univ Kiel, Inst Geosci, D-24118 Kiel, Germany; 5.Dalhousie Univ, Dept Oceanog, Halifax, NS, Canada
推荐引用方式 GB/T 7714	Doering, Kristin,Ehlert, Claudia,Martinez, Philippe,et al. Latitudinal variations in delta(30)Sj and delta N-15 signatures along the Peruvian shelf: quantifying the effects of nutrient utilization versus denitrification over the past 600 years[J],2019,16(10):2163-2180.
APA	Doering, Kristin,Ehlert, Claudia,Martinez, Philippe,Frank, Martin,&Schneider, Ralph.(2019).Latitudinal variations in delta(30)Sj and delta N-15 signatures along the Peruvian shelf: quantifying the effects of nutrient utilization versus denitrification over the past 600 years.BIOGEOSCIENCES,16(10),2163-2180.
MLA	Doering, Kristin,et al."Latitudinal variations in delta(30)Sj and delta N-15 signatures along the Peruvian shelf: quantifying the effects of nutrient utilization versus denitrification over the past 600 years".BIOGEOSCIENCES 16.10(2019):2163-2180.