DOI: 10.1029/2019GB006236
论文题名: Nutrient Controls on Export Production in the Southern Ocean
作者: Arteaga L.A. ; Pahlow M. ; Bushinsky S.M. ; Sarmiento J.L.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2019
卷: 33, 期: 8 语种: 英语
英文关键词: carbon flux
; diatom
; drawdown
; nitrate
; nutrient cycling
; nutrient limitation
; organic carbon
; particulate organic carbon
; polar front
; silicate
; silicification
; Bacillariophyta
学科: carbon
; export
; limitation
; nutrient
; phytoplankton
中文摘要: 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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/160117
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
Arteaga L.A.,Pahlow M.,Bushinsky S.M.,et al. Nutrient Controls on Export Production in the Southern Ocean[J]. Global Biogeochemical Cycles,2019-01-01,33(8)