气候变化领域集成服务门户(CCPortal): Dissolved Organic Nitrogen Production and Consumption in Eastern Tropical South Pacific Surface Waters

CCPortal

DOI	10.1029/2017GB005875
	Dissolved Organic Nitrogen Production and Consumption in Eastern Tropical South Pacific Surface Waters
	Knapp A.N.; Casciotti K.L.; Prokopenko M.G.
发表日期	2018
ISSN	0886-6236
EISSN	1944-9224
起始页码	769
结束页码	783
卷号	32 期号:5
英文摘要	Models of dissolved organic nitrogen (DON) production and consumption indicate that marine DON is produced in the euphotic zone, especially in upwelling environments, and is consumed as it transits into more oligotrophic regions where it may support export production. However, evaluation of such models is data limited, and in particular, few measurements of DON concentration and/or nitrogen isotopic composition (“δ15N”) exist from the South Pacific. Here we present measurements of the concentration and δ15N of DON collected in the eastern tropical South Pacific during the austral summers of 2010 (El Niño) and 2011 (La Niña). The concentration and δ15N of DON from the eastern tropical South Pacific are broadly consistent with prior measurements elsewhere, that is, DON concentrations of 5 ± 1 μM and DON δ15N of 5 ± 1‰, but variations were associated with DON production and consumption. Specifically, surface ocean chlorophyll a concentrations were highly correlated with upper 50-m DON stocks (r = 0.96), consistent with a photosynthetic source for DON. Additionally, upper 50-m DON stocks and their δ15N were significantly negatively correlated (r = −0.84, p = 0.0006), indicating that DON was consumed in surface waters with an isotope effect of 5.5 ± 1.2‰. These results inform our understanding of the controls of DON distributions in the surface ocean and indicate that DON may support export production in nitrate-poor surface waters, which may decouple new from gross production. ©2018. American Geophysical Union. All Rights Reserved.
英文关键词	dissolved organic nitrogen; DON; eastern tropical South Pacific; nitrogen; nitrogen isotopes; South Pacific
语种	英语
scopus关键词	chlorophyll a; dissolved organic nitrogen; El Nino; euphotic zone; isotopic composition; La Nina; nitrogen isotope; oligotrophic environment; surface water; Pacific Ocean; Pacific Ocean (South)
来源期刊	Global Biogeochemical Cycles
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/129833
作者单位	Earth, Ocean, and Atmospheric Science Department, Florida State University, Tallahassee, FL, United States; Department of Earth System Science, Stanford University, Stanford, CA, United States; Geology Department, Pomona College, Claremont, CA, United States
推荐引用方式 GB/T 7714	Knapp A.N.,Casciotti K.L.,Prokopenko M.G.. Dissolved Organic Nitrogen Production and Consumption in Eastern Tropical South Pacific Surface Waters[J],2018,32(5).
APA	Knapp A.N.,Casciotti K.L.,&Prokopenko M.G..(2018).Dissolved Organic Nitrogen Production and Consumption in Eastern Tropical South Pacific Surface Waters.Global Biogeochemical Cycles,32(5).
MLA	Knapp A.N.,et al."Dissolved Organic Nitrogen Production and Consumption in Eastern Tropical South Pacific Surface Waters".Global Biogeochemical Cycles 32.5(2018).