On the interaction of stochastic forcing and regime dynamics
- 1Atmospheric, Oceanic, and Planetary Physics, University of Oxford, Oxford, UK
- 2Institute for Meteorology and Climate (IMK-TRO), Karlsruher Institute of Technology, Germany
- 1Atmospheric, Oceanic, and Planetary Physics, University of Oxford, Oxford, UK
- 2Institute for Meteorology and Climate (IMK-TRO), Karlsruher Institute of Technology, Germany
Abstract. In this paper we investigate the curious ability of stochastic forcing to increase the persistence of regimes, in a low-order, stochastically forced system. In recent years, evidence from both simple models and climate simulations have suggested that stochastic forcing can act as a stabilising force to increase regime persistence, but the mechanisms driving this potential reinforcement are unclear. Using a six-mode truncation of a barotropic β-plane model, featuring transitions between analogues of zonal and blocked flow conditions, we show that moderate levels of fast-varying stochastic forcing can increase the low-frequency variability of the system, and act asymmetrically to increase the persistence of certain regimes. We show that the presence of a deterministically-inaccessible unstable fixed point, and the low-dimensionality of the flow during blocking, are vital dynamical components that allow this stochastic persistence to occur. We present a simple geometric argument that explains how stochastic forcing can slow the growth of instabilities, which may have more general applicability in understanding stochastic chaotic systems.
- Preprint
(4639 KB) -
Supplement
(861 KB) - BibTeX
- EndNote
Joshua Dorrington and Tim Palmer
Status: open (until 16 Sep 2022)
-
CC1: 'Comment on egusphere-2022-523', Paul PUKITE, 22 Jul 2022
reply
Nice use of chain-rule, almost have it solved. The symbolic computation software should be able to do the rest, Wolfram Apha will work in a pinch if sympy can't handle the reduction. Good luck!
Joshua Dorrington and Tim Palmer
Joshua Dorrington and Tim Palmer
Viewed
HTML | XML | Total | Supplement | BibTeX | EndNote | |
---|---|---|---|---|---|---|
91 | 34 | 9 | 134 | 15 | 4 | 4 |
- HTML: 91
- PDF: 34
- XML: 9
- Total: 134
- Supplement: 15
- BibTeX: 4
- EndNote: 4
Viewed (geographical distribution)
Country | # | Views | % |
---|
Total: | 0 |
HTML: | 0 |
PDF: | 0 |
XML: | 0 |
- 1