DOI: 10.1002/2014GB004814
Scopus记录号: 2-s2.0-84901101600
论文题名: Natural biogeochemical cycle of mercury in a global three-dimensional ocean tracer model
作者: Zhang Y ; , Jaeglé L ; , Thompson L
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2014
卷: 28, 期: 5 起始页码: 553
结束页码: 570
语种: 英语
英文关键词: 3-D model
; biogeochemical cycle
; global modeling
; mercury
; oceanic model
Scopus关键词: Biogeochemistry
; Computer simulation
; Ecology
; Oceanography
; 3-d modeling
; Anthropogenic inputs
; Atmospheric boundary conditions
; Biogeochemical cycle
; Global modeling
; Mercury distribution
; North Atlantic Ocean
; Oceanic model
; Mercury (metal)
; air-sea interaction
; anthropogenic effect
; biogeochemical cycle
; biological pump
; global perspective
; mercury (element)
; three-dimensional modeling
; tracer
; water mass
; Atlantic Ocean
; Atlantic Ocean (North)
; Pacific Ocean
; Pacific Ocean (North)
英文摘要: We implement mercury (Hg) biogeochemistry in the offline global 3-D ocean tracer model (OFFTRAC) to investigate the natural Hg cycle, prior to any anthropogenic input. The simulation includes three Hg tracers: dissolved elemental (Hg0aq), dissolved divalent (Hg IIaq), and particle-bound mercury (HgP aq). Our Hg parameterization takes into account redox chemistry in ocean waters, air-sea exchange of Hg0, scavenging of Hg IIaq onto sinking particles, and resupply of Hg IIaq at depth by remineralization of sinking particles. Atmospheric boundary conditions are provided by a global simulation of the natural atmospheric Hg cycle in the GEOS-Chem model. In the surface ocean, the OFFTRAC model predicts global mean concentrations of 0.16 pM for total Hg, partitioned as 80% HgIIaq, 14% Hg0 aq, and 6% HgPaq. Total Hg concentrations increase to 0.38 pM in the thermocline/intermediate waters (between the mixed layer and 1000-m depth) and 0.82 pM in deep waters (below 1000-m), reflecting removal of Hg from the surface to the subsurface ocean by particle sinking followed by remineralization at depth. Our model predicts that Hg concentrations in the deep North Pacific Ocean (>2000-m) are a factor of 2-3 higher than in the deep North Atlantic Ocean. This is the result of cumulative input of Hg from particle remineralization as deep waters transit from the North Atlantic to the North Pacific on their ~2000 year journey. The model is able to reproduce the relatively uniform concentrations of total Hg observed in the old deep waters of the North Pacific Ocean (observations: 1.2-±-0.4 pM; model: 1.1-±-0.04 pM) and Southern Ocean (observations: 1.1-±-0.2 pM; model: 0.8-±-0.02 pM). However, the modeled concentrations are factors of 5-6 too low compared to observed concentrations in the surface ocean and in the young water masses of the deep North Atlantic Ocean. This large underestimate for these regions implies a factor of 5-6 anthropogenic enhancement in Hg concentrations. Key Points The first global 3-D ocean tracer model for mercury is developed Biological pump and water mass age mainly decide mercury distribution Comparison against present-day observations reveals human perturbation ©2014. 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/77487
Appears in Collections: 气候变化事实与影响
There are no files associated with this item.
作者单位: Department of Atmospheric Sciences, University of Washington, Seattle WA, United States; School of Oceanography, University of Washington, Seattle WA, United States
Recommended Citation:
Zhang Y,, Jaeglé L,, Thompson L. Natural biogeochemical cycle of mercury in a global three-dimensional ocean tracer model[J]. Global Biogeochemical Cycles,2014-01-01,28(5)