| Autor: |
Bellucci, Alessio, Mattei, Denis, Ruggieri, Paolo, Famooss Paolini, Luca |
| Předmět: |
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| Zdroj: |
Geophysical Research Letters; 9/16/2022, Vol. 49 Issue 17, p1-10, 10p |
| Abstrakt: |
The connection between the Atlantic meridional overturning circulation (AMOC) and the Atlantic multidecadal variability (AMV) is inspected in a suite of pre‐industrial integrations from the 6th phase of the Coupled Model Inter‐comparison Project (CMIP6), using a change‐point detection method to identify different AMOC‐AMV co‐variability regimes. A key finding of this study is that models robustly simulate multi‐decadal windows where the AMV and the AMOC are essentially uncorrelated. These regimes coexist with longer periods with relatively high correlation. Drops and recoveries of correlation are found to be often abrupt and confined in a temporal window of the order of 10 years. Phenomenological evidence suggests that the no‐correlation regimes may be explained by drops in the variance of the AMOC: a less variable meridional heat transport leads to a suppressed co‐variability of the AMV, leaving a larger role for non‐AMOC drivers, consistent with a non‐stationary AMOC‐stationary noise interpretative framework. Plain Language Summary: The North Atlantic Ocean exhibits prominent multi‐decadal variability, modulating the climate and weather of the surrounding continental regions. A relevant fraction of this variability is explained by the interplay between ocean circulation and heat transport, leading to coordinated, basin‐wide fluctuations in surface temperatures. In this study we analyze the multi‐century stability of this interaction in a suite of climate model simulations, providing evidence for the occurrence of spontaneous breakings in the connection between ocean circulation and ocean surface temperatures. These events can be abrupt in time, last from decades to centuries, and are associated with synchronous changes in the characteristics of the oceanic variability. A conceptual model is provided to interpret these transitions. These findings raise concern about the potential occurrence of similar decoupling episodes in the future, and the need for adequately long observational records to fully represent the long‐term modulation of multi‐decadal variability in the Atlantic sector. Key Points: Spontaneous breakings of the Atlantic meridional overturning circulation‐Atlantic multidecadal variability (AMOC‐AMV) connection are found in a suite of multi‐century control simulations from the 6th phase of the Coupled Model Inter‐comparison ProjectThe inception and demise of these AMOC‐AMV de‐coupling events can be abrupt in scale and last several decades or centuriesDecoupling between AMOC and AMV is more likely to occur when their respective variance is low [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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