Variability in the noise-induced modes of climate dynamics

• Published in: Physics letters. A 2020-07, Vol.384 (19), p.126411, Article 126411
• Main Authors: Alexandrov, Dmitri V., Bashkirtseva, Irina A., Ryashko, Lev B.
• Format: Article
• Language: English
• Subjects: Bifurcations; Climate variability; Nonlinear dynamics; Stochastic forcing
• ISSN: 0375-9601; 1873-2429
• DOI: 10.1016/j.physleta.2020.126411

•Stochastic variant of climate model is considered.•Stochastic excitability is studied.•Generation of mixed-mode oscillations is discussed. New features of noise-induced climate variability are revealed on the basis of the three-dimensional model derived by Saltzman and Maasch. It is shown that the climate system can be highly noise excitable and it possesses the large-amplitude fluctuations even in those regions where its akin deterministic model does not contain any self-sustained oscillations. Intermittency in small- and large amplitude climate fluctuations between different basins of attraction of a limit cycle and stable equilibria substantially influencing the climate state (from warm to cold and vice versa) are found at various noise intensities. Suddenly occurring jumps between the basins of attraction of two stable equilibria corresponding to the warm and cold climate states are statistically confirmed under a certain diapason of noise intensities. The climate system undergoes transitions between its equilibria in the presence of noise in its prognostic variables. In addition, such transitions become more likely with increasing the noise intensity.