DOI: 10.1002/2016GB005452
Scopus记录号: 2-s2.0-85014223615
论文题名: Development of a global ocean mercury model with a methylation cycle: Outstanding issues
作者: Semeniuk K ; , Dastoor A
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2017
卷: 31, 期: 2 起始页码: 400
结束页码: 433
语种: 英语
英文关键词: mercury methylation cycle
; ocean 3-D model
Scopus关键词: biogeochemistry
; deep water
; global ocean
; intermediate water
; mercury (element)
; methylation
; particulate organic carbon
; remineralization
; remobilization
; scavenging (chemistry)
; seafloor
; sediment chemistry
; three-dimensional modeling
; Antarctica
; Arctic
; Pacific Ocean
; Pacific Ocean (North)
; Southern Ocean
英文摘要: We present a newly developed global ocean mercury (Hg) transport and biogeochemistry model and use preanthropogenic equilibrium simulations to highlight physical and chemical processes which reveal significant knowledge gaps that need to be addressed. As with previous 3-D ocean Hg model work we use a bulk chemistry scheme based on particulate organic carbon remineralization. We also include an explicit methylation cycle based on available reaction rates. The methylation to demethylation rate ratio based on various field studies is found to be inconsistent with the concentration ratios measured in the Southern Ocean around Antarctica and in the Arctic. There is also model-measurement disagreement in the old waters of the tropical and North Pacific Ocean. The model produces an intermediate water maximum in total Hg in this region reflecting the higher age of water which is absent in observations. The model also underestimates total Hg concentrations in the deepest waters in this region. These disagreements in depth profile shape point to an inadequate representation of scavenging and sedimentation and possibly seabed emission or remobilization of Hg. In addition, the total Hg distribution differences compared to previous model work reflect sensitivity to ocean model transport characteristics and in particular the tracer diffusion. The residence time of Hg in the global ocean and the surface evasion flux of elemental Hg is sensitive to such model aspects. We find a global ocean Hg turnover time against sediment burial to be about 1100 years which is within the range of previous studies. ©2017 Her Majesty the Queen in Right of Canada. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/77769
Appears in Collections: 气候变化事实与影响
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作者单位: Air Quality Research Division, Environment and Climate Change Canada, Dorval, QC, Canada
Recommended Citation:
Semeniuk K,, Dastoor A. Development of a global ocean mercury model with a methylation cycle: Outstanding issues[J]. Global Biogeochemical Cycles,2017-01-01,31(2)