气候变化领域集成服务门户(CCPortal): Nutrient Controls on Export Production in the Southern Ocean

CCPortal

DOI	10.1029/2019GB006236
	Nutrient Controls on Export Production in the Southern Ocean
	Arteaga L.A.; Pahlow M.; Bushinsky S.M.; Sarmiento J.L.
发表日期	2019
ISSN	0886-6236
EISSN	1944-9224
起始页码	942
结束页码	956
卷号	33 期号:8
英文摘要	We use observations from novel biogeochemical profiling floats deployed by the Southern Ocean Carbon and Climate Observations and Modeling program to estimate annual net community production (ANCP; associated with carbon export) from the seasonal drawdown of mesopelagic oxygen and surface nitrate in the Southern Ocean. Our estimates agree with previous observations in showing an increase in ANCP in the vicinity of the polar front (∼3 mol C m−2 y−1), compared to lower rates in the subtropical zone (≤ 1 mol C m−2 y−1) and the seasonal ice zone (<2 mol C m−2 y−1). Paradoxically, the increase in ANCP south of the subtropical front is associated with elevated surface nitrate and silicate concentrations, but decreasing surface iron. We hypothesize that iron limitation promotes silicification in diatoms, which is evidenced by the low silicate to nitrate ratio of surface waters around the Antarctic polar front. High diatom silicification increases the ballasting effect of particulate organic carbon and overall ANCP in this region. A model-based assessment of our methods shows a good agreement between ANCP estimates based on oxygen and nitrate drawdown and the modeled downward organic carbon flux at 100 m. This agreement supports the presumption that net biological consumption is the dominant process affecting the drawdown of these chemical tracers and that, given sufficient data, ANCP can be inferred from observations of oxygen and/or nitrate drawdown in the Southern Ocean. ©2019. American Geophysical Union. All Rights Reserved.
英文关键词	carbon; export; limitation; nutrient; phytoplankton
语种	英语
scopus关键词	carbon flux; diatom; drawdown; nitrate; nutrient cycling; nutrient limitation; organic carbon; particulate organic carbon; polar front; silicate; silicification; Bacillariophyta
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/129722
作者单位	Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ, United States; GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
推荐引用方式 GB/T 7714	Arteaga L.A.,Pahlow M.,Bushinsky S.M.,et al. Nutrient Controls on Export Production in the Southern Ocean[J],2019,33(8).
APA	Arteaga L.A.,Pahlow M.,Bushinsky S.M.,&Sarmiento J.L..(2019).Nutrient Controls on Export Production in the Southern Ocean.Global Biogeochemical Cycles,33(8).
MLA	Arteaga L.A.,et al."Nutrient Controls on Export Production in the Southern Ocean".Global Biogeochemical Cycles 33.8(2019).