DOI: 10.1016/j.epsl.2018.06.031
Scopus记录号: 2-s2.0-85049567646
论文题名: Ocean and climate response to North Atlantic seaway changes at the onset of long-term Eocene cooling
作者: Vahlenkamp M. ; Niezgodzki I. ; De Vleeschouwer D. ; Lohmann G. ; Bickert T. ; Pälike H.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 498 起始页码: 185
结束页码: 195
语种: 英语
英文关键词: Deep Western Boundary Currents
; Earth System Model
; Eocene cooling
; Greenland–Scotland Ridge
; Northern Component Water
Scopus关键词: Climate change
; Glacial geology
; Greenhouse gases
; Greenhouses
; Surface waters
; Tectonics
; Atmospheric greenhouse
; Deep western boundary currents
; Deep-water formation
; Earth system model
; Greenland-Scotland Ridge
; North Atlantic Ocean Circulation
; Scotland
; Tectonic boundary conditions
; Oceanography
; boundary current
; cooling
; deep water
; Eocene
; modeling
; paleoceanography
; paleoclimate
; paleocurrent
; Arctic Ocean
; Atlantic Ocean
; Atlantic Ocean (North)
英文摘要: Around the early–middle Eocene boundary, the first occurrence of contourite drift sediments and widespread deep ocean erosion indicate changes in the North Atlantic ocean circulation. Interestingly, these changes coincide with the first steps of Cenozoic cooling from the Paleogene greenhouse climate towards the modern icehouse. The cause for this ocean circulation reorganization is poorly understood since modern water mass tracers may have worked fundamentally different in the past and the paleoceanographic proxy record is limited in both time and space. As a result, it is challenging to reliably reconstruct the climatic and tectonic boundary conditions e.g. atmospheric greenhouse gas concentration and the depth and geometry of developing and closing passages between ocean basins. In this study, we attempt to identify thresholds in tectonic gateway passages and atmospheric CO2 concentration, using the fully coupled Earth System Model COSMOS. Indeed, the simulation of Earth's past climates can unravel the physical processes driving deep-water formation in a greenhouse world. Specifically, we use COSMOS to evaluate the impact of changes in the North Atlantic gateways at the early–middle Eocene boundary on the North Atlantic Deep Western Boundary Currents under low obliquity configuration. We find that Northern Component Waters start to form when the Greenland Scotland Ridge reaches a threshold depth of deeper than 200 m, while the Arctic Ocean is still shut off from the North Atlantic. In this scenario, the relatively deep Greenland Scotland Ridge allows for sufficient inflow of warm, salty Atlantic surface waters into the Nordic Seas to initiate convection during winter cooling. Opening the seaway towards the Arctic leads to a cessation of Northern Component Water formation as it allows for inflow of brackish surface waters into the northern Nordic Seas, hindering Northern Component Water formation. © 2018 The Authors Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109745
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: MARUM – Center for Marine Environmental Sciences, University of Bremen, Leobener Strasse 8, Bremen, 28359, Germany; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bussestr. 24, Bremerhaven, 27570, Germany; ING PAN – Institute of Geological Sciences, Polish Academy of Sciences, Research Center in Kraków, Biogeosystem Modelling Laboratory, Kraków, Poland
Recommended Citation:
Vahlenkamp M.,Niezgodzki I.,De Vleeschouwer D.,et al. Ocean and climate response to North Atlantic seaway changes at the onset of long-term Eocene cooling[J]. Earth and Planetary Science Letters,2018-01-01,498