TY  - JOUR
A1  - Born, Andreas
A1  - Stocker, Thomas F.
A1  - Raible, Christoph C.
A1  - Levermann, Anders
T1  - Is the Atlantic subpolar gyre bistable in comprehensive coupled climate models?
JF  - Climate dynamics : observational, theoretical and computational research on the climate system
N2  - The Atlantic subpolar gyre (SPG) is one of the main drivers of decadal climate variability in the North Atlantic. Here we analyze its dynamics in pre-industrial control simulations of 19 different comprehensive coupled climate models. The analysis is based on a recently proposed description of the SPG dynamics that found the circulation to be potentially bistable due to a positive feedback mechanism including salt transport and enhanced deep convection in the SPG center. We employ a statistical method to identify multiple equilibria in time series that are subject to strong noise and analyze composite fields to assess whether the bistability results from the hypothesized feedback mechanism. Because noise dominates the time series in most models, multiple circulation modes can unambiguously be detected in only six models. Four of these six models confirm that the intensification is caused by the positive feedback mechanism.
Y1  - 2013
U6  - https://doi.org/10.1007/s00382-012-1525-7
SN  - 0930-7575
VL  - 40
IS  - 11-12
SP  - 2993
EP  - 3007
PB  - Springer
CY  - New York
ER  -