Multistability in a coupled ocean-atmosphere reducedāorder model: nonlinear temperature equations
Hamilton, O.; Demaeyer, J.; Vannitsem, S.; Crucifix, M. (2023). Multistability in a coupled ocean-atmosphere reducedāorder model: nonlinear temperature equations. Q. J. R. Meteorol. Soc. 149(757): 3423-3439. https://dx.doi.org/10.1002/qj.4564
In: Quarterly Journal of the Royal Meteorological Society. Royal Meteorological Society: Bracknell, Berks. ISSN 0035-9009; e-ISSN 1477-870X, more
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Abstract |
Multistabilities in the oceanāatmosphere flow were found in a reduced-order oceanāatmosphere coupled model, by solving the nonlinear temperature equations numerically. In this article, we explain how the full nonlinear StefanāBolzmann law was implemented numerically and the resulting change to the system dynamics was compared with the original model where these terms were linearised. Multiple stable solutions were found that display distinct oceanāatmosphere flows, as well as different Lyapunov stability properties. In addition, distinct low-frequency variability (LFV) behaviour was observed in multiple attractors. We investigated the impact on these solutions of changing the magnitude of the oceanāatmospheric coupling, as well as the atmospheric emissivity, to simulate an increasing greenhouse effect. Where multistabilities exist for fixed parameters, the possibility for tipping between solutions was investigated, but tipping did not occur in this version of the model where there is a constant solar forcing. This study was undertaken using a reduced-order coupled quasigeostrophic oceanāatmosphere model. |
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