Complex systems can exhibit sudden transitions or regime shifts from one stable state to another, typically referred to as critical transitions. It becomes a great challenge to identify a robust warning sufficiently early that action can be taken to avert a regime shift. We employ landscape-flux theory from nonequilibrium statistical mechanics as a general framework to quantify the global stability of ecological systems and provide warning signals for critical transitions. We quantify the average flux as the nonequilibrium driving force and the dynamical origin of the nonequilibrium transition while the entropy production rate as the nonequilibrium thermodynamic cost and thermodynamic origin of the nonequilibrium transition. Average flux, entropy production, nonequilibrium free energy, and time irreversibility quantified by the difference in cross-correlation functions forward and backward in time can serve as early warning signals for critical transitions much earlier than other conventional predictors. We utilize a classical shallow lake model as an exemplar for our early warning prediction. Our proposed method is general and can be readily applied to assess the resilience of many other ecological systems. The early warning signals proposed here can potentially predict critical transitions earlier than established methods and perhaps even sufficiently early to avert catastrophic shifts.
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Early‐Warning Signals for Critical Temperature Transitions
Critical transitions of the state variable (temperature) in dynamic climate systems often lead to catastrophic consequence, whereas the effort to reverse the transitions usually lags behind. However, these transitions are characterized by the slowing down of recovery from perturbations, carrying early‐warning signals that can be used to predict system bifurcation. In this study, we employ the conceptual framework of pitchfork bifurcation and analyze the early‐warning signals in temperature time series for critical slowing down prior to both the early 20th century global warming and heat waves. We also investigate the urban signature in these heat waves. The emergence of early‐warning signals before heat waves provides new insights into the underlying mechanisms (e.g., possible feedback via land‐atmosphere interactions). In particular, given the increasing frequency and intensity of heat extremes, the results will facilitate the design of countermeasures to reserve the tipping and restore the resilience of climate systems.
more » « less- Award ID(s):
- 1930629
- PAR ID:
- 10386847
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Geophysical Research Letters
- Volume:
- 47
- Issue:
- 14
- ISSN:
- 0094-8276
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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