DOI: 10.1029/2017GB005852
论文题名: Formation and Maintenance of the GEOTRACES Subsurface-Dissolved Iron Maxima in an Ocean Biogeochemistry Model
作者: Pham A.L.D. ; Ito T.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2018
卷: 32, 期: 6 语种: 英语
英文关键词: biogeochemical cycle
; biogeochemistry
; continental shelf
; desorption
; dissolution
; dissolved organic matter
; euphotic zone
; global ocean
; hydrothermal vent
; iron
; ligand
; observational method
; parameterization
; scavenging (chemistry)
; thermocline
; Atlantic Ocean
; Pacific Ocean
学科: biogeochemistry
; dissolved iron
; GEOTRACES
; observations
; ocean modeling
中文摘要: Recent GEOTRACES transects revealed basin-scale patterns of dissolved iron in the global oceans, providing a unique opportunity to test numerical models and to improve our understanding of the iron cycling. Subsurface maxima of dissolved iron in the upper ocean thermocline are observed in various transects, which can play an important role in regulating marine productivity due to their proximity to the surface euphotic layer. An ocean biogeochemistry model with refined parameterizations of iron cycling is used to examine the mechanisms controlling the formation and maintenance of these subsurface maxima. The model includes the representation of three iron sources including dust deposition, continental shelves, and hydrothermal vents. Two classes of organic ligands are parameterized based on the dissolved organic matter and apparent oxygen utilization. Parameterizations of particle-dependent scavenging and desorption are included. Although the model still struggles in fully capturing the observed dissolved iron distribution, it starts reproducing some major features, especially in the main thermocline. A suite of numerical sensitivity experiments suggests that the release of scavenged iron associated with sinking organic particles forms the subsurface-dissolved iron maxima in high-dust regions of the Indian and Atlantic Oceans. In low-dust regions of the Pacific basin, the subsurface-dissolved iron extrema are sustained by inputs from the continental shelves or hydrothermal vents. In all cases, subsurface ligands produced by the remineralization of organic particles retain the dissolved iron and play a central role in the maintenance of the subsurface maxima in our model. Thus, the parameterization of subsurface ligands has a far-reaching impact on the representation of global iron cycling and biological productivity in ocean biogeochemistry models. ©2018. 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/160225
Appears in Collections: 气候变化与战略
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作者单位: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, United States
Recommended Citation:
Pham A.L.D.,Ito T.. Formation and Maintenance of the GEOTRACES Subsurface-Dissolved Iron Maxima in an Ocean Biogeochemistry Model[J]. Global Biogeochemical Cycles,2018-01-01,32(6)