DOI: 10.1007/s00382-016-3111-x
Scopus记录号: 2-s2.0-84964282443
论文题名: Assessing reconstruction techniques of the Atlantic Ocean circulation variability during the last millennium
作者: Moreno-Chamarro E. ; Ortega P. ; González-Rouco F. ; Montoya M.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2017
卷: 48, 期: 2017-03-04 起始页码: 799
结束页码: 819
语种: 英语
英文关键词: AMOC
; Florida Current
; Last millennium
; Little Ice Age
; Pseudo-reconstructions
; Thermal-wind transport
英文摘要: We assess the use of the meridional thermal-wind transport estimated from zonal density gradients to reconstruct the oceanic circulation variability during the last millennium in a forced simulation with the ECHO-G coupled climate model. Following a perfect-model approach, model-based pseudo-reconstructions of the Atlantic meridional overturning circulation (AMOC) and the Florida Current volume transport (FCT) are evaluated against their true simulated variability. The pseudo-FCT is additionally verified as proxy for AMOC strength and compared with the available proxy-based reconstruction. The thermal-wind component reproduces most of the simulated AMOC variability, which is mostly driven by internal climate dynamics during the preindustrial period and by increasing greenhouse gases afterwards. The pseudo-reconstructed FCT reproduces well the simulated FCT and reasonably well the variability of the AMOC strength, including the response to external forcing. The pseudo-reconstructed FCT, however, underestimates/overestimates the simulated variability at deep/shallow levels. Density changes responsible for the pseudo-reconstructed FCT are mainly driven by zonal temperature differences; salinity differences oppose but play a minor role. These results thus support the use of the thermal-wind relationship to reconstruct the oceanic circulation past variability, in particular at multidecadal timescales. Yet model-data comparison highlights important differences between the simulated and the proxy-based FCT variability. ECHO-G simulates a prominent weakening in the North Atlantic circulation that contrasts with the reconstructed enhancement. Our model results thus do not support the reconstructed FC minimum during the Little Ice Age. This points to a failure in the reconstruction, misrepresented processes in the model, or an important role of internal ocean dynamics. © 2016, The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53372
Appears in Collections: 过去全球变化的重建
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作者单位: Dto. de Astrofísica y Ciencias de la Atmósfera, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid, Spain; Max Planck Institute for Meteorology, Hamburg, Germany; International Max Planck Research School on Earth System Modelling, Hamburg, Germany; Department of Meteorology, National Centre for Atmospheric Science-Climate, University of Reading, Reading, United Kingdom; Facultad de Ciencias Físicas, Instituto de Geociencias (UCM-CSIC), Universidad Complutense de Madrid, Madrid, Spain
Recommended Citation:
Moreno-Chamarro E.,Ortega P.,González-Rouco F.,et al. Assessing reconstruction techniques of the Atlantic Ocean circulation variability during the last millennium[J]. Climate Dynamics,2017-01-01,48(2017-03-04)