DOI: 10.1002/gbc.20090
Scopus记录号: 2-s2.0-84884473019
论文题名: Eddy compensation and controls of the enhanced sea-to-air CO2 flux during positive phases of the Southern Annular Mode
作者: Dufour C ; O ; , Sommer J ; L ; , Gehlen M ; , Orr J ; C ; , Molines J ; -M ; , Simeon J ; , Barnier B
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2013
卷: 27, 期: 3 起始页码: 950
结束页码: 961
语种: 英语
英文关键词: eddies
; natural CO2
; southern annular mode
; Southern Ocean
Scopus关键词: Atmospheric reanalysis
; Dissolved inorganic carbon
; eddies
; Natural CO
; Southern Annular Mode
; Southern ocean
; Vertical gradients
; Wind driven upwelling
; Computer simulation
; Oceanography
; pH
; Carbon dioxide
; air-sea interaction
; carbon dioxide
; carbon flux
; diffusion
; eddy
; Ekman layer
; flux measurement
; mixed layer
; numerical model
; upwelling
; Southern Ocean
英文摘要: The current positive trend in the Southern Annular Mode (SAM) is thought to reduce the growth rate of the Southern Ocean CO2 sink because enhanced wind-driven upwelling of dissolved inorganic carbon (DIC) increases outgassing of natural CO2. However, no study to date has quantified the potentially large role of mesoscale eddies in compensating intensified upwelling nor the mixed-layer processes in terms of their effects on CO 2 fluxes. Here we report on results from two new simulations in a regional 0.5° eddying model of the Southern Ocean. The first simulation is forced with interannually varying atmospheric reanalysis and coupled to a biogeochemistry model run under constant preindustrial atmospheric CO 2. The second simulation is like the first except that superimposed on the forcing is a poleward shifted and intensified westerlies wind anomaly consistent with the positive phase of the SAM. In response to the SAM, the Southern Ocean's sea-to-air CO2 flux is enhanced by 0.1 Pg C yr -1 per standard deviation of the SAM, mostly from the Antarctic Zone (AZ), where enhanced surface DIC is only partly compensated by enhanced surface alkalinity. Increased mixed-layer DIC in the AZ results from a combination of increased upwelling below the mixed layer and increased vertical diffusion at the base of the mixed layer. Previous studies overlooked the latter. Thus, upward supply of DIC and alkalinity depends on associated vertical gradients just below the mixed layer, which are affected by interior ocean transport. Our eddying model study suggests that about one third of the SAM enhancement of the Ekman-induced northward DIC transport is compensated by southward transport from standing and transient eddies. Key Points At the surface, SAM-enhanced DIC is partly compensated by enhanced alkalinityThe mixed-layer DIC in the AZ increases mainly from vertical diffusion ©2013. 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/77571
Appears in Collections: 气候变化事实与影响
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作者单位: Laboratoire des Ecoulements Géophysiques et Industriels, CNRS-Université de Grenoble, Grenoble, France; LSCE/IPSL, Laboratoire des Sciences du Climat et l'Environnement, CEA-CNRS-UVSQ, Gif-sur-Yvette, France; Laboratoire de Glaciologie et Géophysique de l'Environnement, CNRS-Université de Grenoble, Grenoble, France
Recommended Citation:
Dufour C,O,, Sommer J,et al. Eddy compensation and controls of the enhanced sea-to-air CO2 flux during positive phases of the Southern Annular Mode[J]. Global Biogeochemical Cycles,2013-01-01,27(3)