Colloid-like Behavior and Topological Phase Transitions in Space Plasmas: Intermittent Low Frequency Turbulence in the Auroral Zone

Chang, Tom

doi:10.1238/physica.topical.089a00080

Cited by 30 publications

(36 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In other words, the magnetic substorm is the set of phenomena during which a reduction in topological complexity in the tail regions takes place (see also Chang, 2001a, 2001b, Consolini and Chang, 2001, 2002. The role of the solar-wind driver would be to enhance the internal noise (i.e.…”

Section: Discussionmentioning

confidence: 99%

“…However, the presence of fractal time statistics of the waiting times could be interpreted in terms of more general complex dynamics associated with the existence of metastable states in an out-of-equilibrium system (Conoslini andChang, 2001, 2002). Recently, Chang (Chang, 2001a(Chang, , 2001b has introduced a new point of view where the configuration of the magnetospheric plasma and field topology might be close to a colloidal phase. In particular, it has been proposed that the dynamics of coherent structures could be similar to that of a stirred colloidal suspension, showing topological phase transitions in the evolution from one critical state to another.…”

Section: Data Description and Analysismentioning

confidence: 99%

“…A possible way to reconcile the apparent controversy between the organised low-dimensional nonlinear behaviour and the near-criticality (SOC-like) behaviour seems to be to look at magnetic substorms in terms of noise induced nonequilibrium and/or topological phase transitions (Chang, 2001a,;Sharma et al, 2001;Sitnov et al, 2000Sitnov et al, , 2001Consolini and Chang, 2002). As a matter of fact, the theory of topological phase transitions in out-of-equilibrium systems provides a natural framework for the understanding of the solar wind-magnetosphere coupling mainly because of its input-output nature.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Fractal time statistics of AE-index burst waiting times: evidence of metastability

Consolini¹,

Michelis

2002

Nonlin. Processes Geophys.

View full text Add to dashboard Cite

Abstract. Recent observations and analyses evidenced that the magnetotail, as well as the magnetospheric dynamics are characterised by a scale-free behaviour and intermittence. These results, along with numerical simulations on cellular automata, suggest that the observed scale-invariance may be due to forced and/or self-organised criticality (FSOC), meaning that the magnetotail operates near a marginally stable state (Chang, 1999). On the other hand, it was underlined that a complex magnetic field topology in the geotail regions may play a relevant role in the impulsive energy relaxation (Consolini and Chang, 2001).

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Data Description and Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fractal time statistics of AE-index burst waiting times: evidence of metastability

Consolini¹,

Michelis

2002

Nonlin. Processes Geophys.

View full text Add to dashboard Cite

show abstract

“…In this framework, magnetic substorms are better described in terms of noise-induced topological transitions in an extended out-of-equilibrium system. In other words, the magnetic substorm is the set of phenomena during which a reduction in topological complexity takes place (Chang, 2001a(Chang, , 2001bChang, 2001, 2002;Consolini and De Michelis, 2002). The role of the solar wind driver would be to enhance the internal noise (i.e.…”

Section: On the Transition From The Anti-persistent To Persistent Regimementioning

confidence: 99%

From pre-storm activity to magnetic storms: a transition described in terms of fractal dynamics

Balasis

Daglis²,

Kapiris³

et al. 2006

Ann. Geophys.

102

126

View full text Add to dashboard Cite

Abstract. We show that distinct changes in scaling parameters of the D st index time series occur as an intense magnetic storm approaches, revealing a gradual reduction in complexity. The remarkable acceleration of energy release -manifested in the increase in susceptibility -couples to the transition from anti-persistent (negative feedback) to persistent (positive feedback) behavior and indicates that the occurence of an intense magnetic storm is imminent. The main driver of the D st index, the V B South electric field component, does not reveal a similar transition to persistency prior to the storm. This indicates that while the magnetosphere is mostly driven by the solar wind the critical feature of persistency in the magnetosphere is the result of a combination of solar wind and internal magnetospheric activity rather than solar wind variations alone. Our results suggest that the development of an intense magnetic storm can be studied in terms of "intermittent criticality" that is of a more general character than the classical self-organized criticality phenomena, implying the predictability of the magnetosphere.

show abstract

“…In the recent past, studies have appeared on the role that chaos, turbulence and near-criticality dynamics might play in the magnetospheric dynamics (Baker et al, 1990;Roberts et al, 1991;Vassiliadis et al, 1990). In this framework, new research perspectives to the investigation of the magnetospheric dynamics were opened by the recent advances in the study of complexity and complex systems (Vassiliadis et al, 1990;Chang, 1999Chang, , 2001aChang, 2001, 2002;Ukhorskiy et al, 2002Ukhorskiy et al, , 2004Balasis et al, 2006;Pulkkinen et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Comparison of chaotic aspects of magnetosphere under various physical conditions using AE index time series

Unnikrishnan

2008

Ann. Geophys.

View full text Add to dashboard Cite

Abstract. The deterministic chaotic behaviour of magnetosphere was analyzed, using AE index time series. The significant chaotic quantifiers like, Lyapunov exponent, spatiotemporal entropy and nonlinear prediction error for AE index time series under various physical conditions were estimated and compared. During high solar activity (1991), the values of Lyapunov exponent for AE index time series representing quiet conditions (yearly mean = 0.5±0.1 min −1 ) have no significant difference from those values for corresponding storm conditions (yearly mean = 0.5±0.17 min −1 ). This implies that, for the cases considered here, geomagnetic storms may not be an additional source to increase or decrease the deterministic chaotic aspects of magnetosphere, especially during high solar activity. During solar minimum period (1994), the seasonal mean value of Lyapunov exponent for AE index time series belong to quiet periods in winter (0.7±0.11 min −1 ) is higher compared to corresponding value of storm periods in winter (0.36±0.09 min −1 ). This may be due to the fact that, stochastic part, which is D st dependent could be more prominent during storms, thereby increasing fluctuations/stochasticity and reducing determinism in AE index time series during storms. It is observed that, during low solar active period (1994), the seasonal mean value of entropy for time series representing storm periods of equinox is greater than that for quiet periods. However, significant difference is not observed between storm and quiet time values of entropy during high solar activity (1991), which is also true for nonlinear prediction error for both low and high solar activities. In the case of both high and low solar activities, the higher standard deviations of yearly mean Lyapunov exponent values for AE index time series for storm periods compared to those for quiet periods might be due to the strong interplay between stochasticity and determinism during storms.Correspondence to: K. Unnikrishnan (kaleekkal unni@yahoo.com) It is inferred that, the external driving forces, mainly due to solar wind, make the solar-magnetosphere-ionosphere coupling more complex, which generates many active degrees of freedom with various levels of coupling among them, under various physical conditions. Hence, the superposition of a large number of active degrees of freedom can modify the stability/instability conditions of magnetosphere.

show abstract

Colloid-like Behavior and Topological Phase Transitions in Space Plasmas: Intermittent Low Frequency Turbulence in the Auroral Zone

Cited by 30 publications

References 8 publications

Fractal time statistics of AE-index burst waiting times: evidence of metastability

Fractal time statistics of AE-index burst waiting times: evidence of metastability

From pre-storm activity to magnetic storms: a transition described in terms of fractal dynamics

Comparison of chaotic aspects of magnetosphere under various physical conditions using AE index time series

Contact Info

Product

Resources

About