Exponential feedback effects in a parametric resonance climate model

Abstract

The variations in the distribution of solar radiation due to the ~ 105 years Milankovitch cycle, which is connected to the Earth eccentricity variation, cannot explain the sharp drop in temperature of 6 °C ÷ 10 °C that marks the transition from the interglacial to the glacial age registered in the last ~ 5.5 106 years temperature variation behavior. More specifically, neglecting other effects, only a temperature variation of 0.2 °C ÷ 0.3 °C can be attributed to this cycle and, therefore, positive feedback effects should be taken into account to explain the registered effect. In the present work, a comparative Wavelet-Fourier analysis of the Vostok recontructed temperature record, for which different sampling steps are taken into account, is performed. Then, a study of exponential feedback effects within a climate parametric resonance model is dealt and discussed. The obtained findings put into evidence an exponential amplification of the temperature variation from the interglacial to the glacial age supporting the hypothesis that the system energization be connected to periodic variations in the internal solar system parameters. More in details, it is shown that, following the parametric resonance climate model, even small oscillations increase over time proportionally to the system energy itself, i.e. exponentially, and hence, a series of connected resonances is able to energize the climate system.

The ∼170 kyr astronomical cycle in the Early Permian Lucaogou Formation of the Junggar Basin

“…Based on these findings, they proposed the "obliquity threshold response model, " suggesting that the ∼170 kyr AM cycle impacts the Earth's climate system through "nonlinear" sedimentary processes, thus regulating the Earth's carbon cycle. This "nonlinear" feature and threshold responce has also been demonstrated in climate models (e.g., stochastic climate models and parametric climate models) and numerical simulation works (Caccamo and Magazù, 2021;Caccamo and Magazù, 2023). However, the specific mechanisms of how the 173 kyr obliquity AM cycle influences Earth's climate are still not fully understood, especially for the old strata beyond Mesozoic Era.…”

“…Additionally, recent climate modeling studies also support these nonlinear features. Caccamo and Magazù (2023) conducted comparative Wavelet-Fourier analysis on reconstructed temperature records, discussing exponential feedback effects in a climate parametric resonance model. They found exponential amplification of temperature changes from interglacial to glacial periods, demonstrating that external orbital forcings provide energy to the climate system through a series of connected resonances.…”

On a New Theory of Climate Interference for MISs and Glacial Terminations from Antarctica Ice-core Records. 1: Interference Model

“…The nonlinear phase locking, in which the external Milankovitch forcing affects the amplitude and period of climate oscillations to satisfy the nonlinear resonance condition [70], is likely the mechanism linking weak forcing perturbations with the induced feedback signals to produce exponential responses. Similarly, the climate parametric resonance model of Caccamo and Magazù [52] introduces a set of positive feedback loops in which the climate system response is non-linearly amplified with a net positive gain. This leads to a self-reinforcing feedback mechanism that amplifies the effects of the small disturbances connected with Milankovitch's cycles including eccentricity [52,71].…”

“…Similarly, the climate parametric resonance model of Caccamo and Magazù [52] introduces a set of positive feedback loops in which the climate system response is non-linearly amplified with a net positive gain. This leads to a self-reinforcing feedback mechanism that amplifies the effects of the small disturbances connected with Milankovitch's cycles including eccentricity [52,71]. Interference is a different phenomenon involving response components at a given time through a process of stochastic energy redistribution to produce the bulk climate wave.…”

“…Indeed, climate responses resulted from an exponential feedback-driven (albedo mechanisms, carbon cycle, etc.) energy-transfer [16,[39][40][41][42][43][44][45][46][47][48][49][50][51][52] from an initial, low-energy, and orbitally paced insolation change [24][25][26]. This viewpoint involves an interesting perspective change in climate studies from being nominal-centric to responsecentric, thus providing new possible interpretative insights into the climate system because response components acquire different characteristics [9].…”