DOI: 10.1007/s00382-014-2271-9
Scopus记录号: 2-s2.0-84920823918
论文题名: An event-based approach to understanding decadal fluctuations in the Atlantic meridional overturning circulation
作者: Allison L. ; Hawkins E. ; Woollings T.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 44, 期: 2017-01-02 起始页码: 163
结束页码: 190
语种: 英语
英文关键词: Atlantic meridional overturning circulation
; Decadal variability
; Events
; Nonlinear response
; Thermohaline circulation
英文摘要: Many previous studies have shown that unforced climate model simulations exhibit decadal-scale fluctuations in the Atlantic meridional overturning circulation (AMOC), and that this variability can have impacts on surface climate fields. However, the robustness of these surface fingerprints across different models is less clear. Furthermore, with the potential for coupled feedbacks that may amplify or damp the response, it is not known whether the associated climate signals are linearly related to the strength of the AMOC changes, or if the fluctuation events exhibit nonlinear behaviour with respect to their strength or polarity. To explore these questions, we introduce an objective and flexible method for identifying the largest natural AMOC fluctuation events in multicentennial/multimillennial simulations of a variety of coupled climate models. The characteristics of the events are explored, including their magnitude, meridional coherence and spatial structure, as well as links with ocean heat transport and the horizontal circulation. The surface fingerprints in ocean temperature and salinity are examined, and compared with the results of linear regression analysis. It is found that the regressions generally provide a good indication of the surface changes associated with the largest AMOC events. However, there are some exceptions, including a nonlinear change in the atmospheric pressure signal, particularly at high latitudes, in HadCM3. Some asymmetries are also found between the changes associated with positive and negative AMOC events in the same model. Composite analysis suggests that there are signals that are robust across the largest AMOC events in each model, which provides reassurance that the surface changes associated with one particular event will be similar to those expected from regression analysis. However, large differences are found between the AMOC fingerprints in different models, which may hinder the prediction and attribution of such events in reality. © 2014, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54640
Appears in Collections: 过去全球变化的重建
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作者单位: NCAS-Climate, Department of Meteorology, University of Reading, Reading, United Kingdom; Met Office, Exeter, United Kingdom
Recommended Citation:
Allison L.,Hawkins E.,Woollings T.. An event-based approach to understanding decadal fluctuations in the Atlantic meridional overturning circulation[J]. Climate Dynamics,2014-01-01,44(2017-01-02)