DOI: 10.1175/JCLI-D-17-0859.1
Scopus记录号: 2-s2.0-85053033960
论文题名: Two AMOC states in response to decreasing greenhouse gas concentrations in the coupled climate model MPI-ESM
作者: Klockmann M. ; Mikolajewicz U. ; Marotzke J.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2018
卷: 31, 期: 19 起始页码: 7969
结束页码: 7984
语种: 英语
英文关键词: Atlantic Ocean
; Climate models
; Climate variability
; Meridional overturning circulation
; Water masses
Scopus关键词: Carbon dioxide
; Climate models
; Glaciers
; Greenhouse gases
; Ice
; Antarctic Bottom Water
; Atlantic meridional overturning circulations
; Atlantic Ocean
; Climate variability
; Meridional overturning circulations
; Non-linear relationships
; North Atlantic Deep Water
; Water mass
; Oceanography
英文摘要: This study analyzes the response of the Atlantic meridional overturning circulation (AMOC) to different CO2 concentrations and two ice sheet configurations in simulations with the coupled climate model MPI-ESM. With preindustrial (PI) ice sheets, there are two different AMOC states within the studied CO2 range: one state with a strong and deep upper overturning cell at high CO2 concentrations and one state with a weak and shallow upper cell at low CO2 concentrations. Changes in AMOC variability with decreasing CO2 indicate two stability thresholds. The strong state is stable above the first threshold near 217 ppm, and the weak state is stable below the second threshold near 190 ppm. Between the two thresholds, both states are marginally unstable, and the AMOC oscillates between them on millennial time scales. The weak AMOC state is stable when Antarctic Bottom Water becomes dense and salty enough to replace North Atlantic Deep Water (NADW) in the deep North Atlantic and when the density gain over the North Atlantic becomes too weak to sustain continuous NADW formation. With Last Glacial Maximum (LGM) ice sheets, the density gain over the North Atlantic and the northward salt transport are enhanced with respect to the PI ice sheet case. This enables active NADW formation and a strong AMOC for the entire range of studied CO2 concentrations. The AMOC variability indicates that the simulated AMOC is far away from a stability threshold with LGM ice sheets. The nonlinear relationship among AMOC, CO2, and prescribed ice sheets provides an explanation for the large intermodel spread of AMOC states found in previous coupled LGM simulations. © 2018 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110672
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: Max Planck Institute for Meteorology, Hamburg, Germany; Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Geesthacht, Germany
Recommended Citation:
Klockmann M.,Mikolajewicz U.,Marotzke J.. Two AMOC states in response to decreasing greenhouse gas concentrations in the coupled climate model MPI-ESM[J]. Journal of Climate,2018-01-01,31(19)