DOI: 10.1029/2019GB006326
论文题名: Iron Distribution in the Subtropical North Atlantic: The Pivotal Role of Colloidal Iron
作者: Kunde K. ; Wyatt N.J. ; González-Santana D. ; Tagliabue A. ; Mahaffey C. ; Lohan M.C.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2019
卷: 33, 期: 12 语种: 英语
英文关键词: biogeochemistry
; biological pump
; colloid
; dissolved inorganic matter
; eolian deposit
; iron
; source-sink dynamics
; subtropical region
; tracer
; Atlantic Ocean
; Atlantic Ocean (North)
学科: colloidal iron
; dissolved iron
; GEOTRACES
; subtropical North Atlantic
中文摘要: The low availability of the essential micronutrient iron (Fe) in the ocean impacts the efficiency of the biological carbon pump, and hence, it is vital to elucidate its sources, sinks, and internal cycling. We present size-fractionated dissolved Fe (dFe, <0.2 μm) measurements from 130 surface samples and 7 full-depth profiles from the subtropical North Atlantic during summer 2017 and demonstrate the pivotal role of colloidal (cFe, 0.02 to 0.2 μm) over soluble (sFe, <0.02 μm) Fe in controlling the dFe distribution. In the surface (<5 m), a strong west-to-east decrease in dFe (1.53 to 0.26 nM) was driven by a dust gradient, which retained dFe predominantly as cFe (61% to 85% of dFe), while sFe remained largely constant at 0.19 ± 0.05 nM. In the euphotic zone, the attenuation of dFe resulted from the depletion of cFe (0% to 30% of dFe), with scavenging as an important driver. In the mesopelagic, cFe was released from sinking biogenic and lithogenic particles, creating a zone of elevated dFe (0.7 to 1.0 nM) between 400 to 1100 m depth. While the ocean interior, below the mesopelagic and above the seafloor boundary, exhibited a narrow range of cFe (40% to 60% of dFe), the abyssal cFe fraction varied in range from 26% to 76% due to interactions with seafloor sediments and a hydrothermal source with almost 100% cFe. Overall, our results produced an hourglass shape for the vertical cFe-to-dFe fraction and highlight the primary control of cFe on the dFe distribution. ©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/160088
Appears in Collections: 气候变化与战略
There are no files associated with this item.
作者单位: Ocean and Earth Sciences, National Oceanography Centre, University of Southampton, Southampton, United Kingdom; Department of Earth, Ocean, and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
Recommended Citation:
Kunde K.,Wyatt N.J.,González-Santana D.,et al. Iron Distribution in the Subtropical North Atlantic: The Pivotal Role of Colloidal Iron[J]. Global Biogeochemical Cycles,2019-01-01,33(12)