IDENTIFICATION OF SELF-ORGANIZED CRITICALITY IN ATMOSPHERIC LOW FREQUENCY VARIABILITY

Fractals ◽  
1999 ◽  
Vol 07 (04) ◽  
pp. 421-425 ◽  
Author(s):  
R. R. JOSHI ◽  
A. M. SELVAM
Keyword(s):  
Low Frequency ◽  
Direct Consequence ◽  
Atmospheric Flows ◽  
Self Organized ◽  
Inverse Power Law ◽  
Power Spectral ◽  
Low Frequency Variability ◽  
Self Organized Criticality ◽  
Non Local ◽  
Temperature Time

Atmospheric flows exhibit long-range spatiotemporal correlations manifested as self-similar fractal geometry to the global cloud cover pattern concomitant with inverse power law form fB. Such non-local connections are ubiquitous to dynamical systems in nature and are identified as signatures of self-organized criticality. Standard models in meteorological theory cannot explain satisfactorily the observed self-organized criticality in atmospheric flows. A recently developed cell dynamical model for atmospheric flows predicts the observed self-organized criticality as a direct consequence of quantumlike mechanics governing flow dynamics. The model predictions are in agreement with continuous periodogram power spectral analyses of two-day mean TOGA temperature time-series. The application of model concepts for prediction of atmospheric low frequency variability is discussed.

scholarly journals Universal spectrum for short period (days) variability in atmospheric total ozone

MAUSAM ◽  
2022 ◽  
Vol 46 (3) ◽  
pp. 297-302
Author(s):  
A. M. SELVAM ◽  
M. RADHAMANI
Keyword(s):  
Energy Spectrum ◽  
Power Law ◽  
Fractal Geometry ◽  
Total Ozone ◽  
Inverse Power ◽  
Atmospheric Flows ◽  
Temporal Correlations ◽  
Self Organized ◽  
Inverse Power Law ◽  
Self Organized Criticality

  Long-range spatio-temporal correlations manifested as the self-similar fractal geometry to the spatial pattern concomitant with inverse power law form for the power spectrum of temporal fluctuations are ubiquitous to real world dynamical systems and are recently identified as signatures of self-organized criticality Self-organised criticality in atmospheric flows is exhibited as the fractal geometry 10 the global cloud cover pattern and the inverse power law form for the atmospheric eddy energy spectrum, In this paper, a recently developed cell dynamical system model for  atmospheric flows is summarized. The model predicts inverse power law form of the statistical normal distribution for atmospheric eddy energy spectrum as a natural consequence of quantum-like mechanics governing atmospheric flows extending up to stratospheric levels and above, Model Predictions are in agreement with continuous periodogram analyses of atmospheric total ozone. Atmospheric total ozone variability (in days) exhibits the temporal signature of self-organized criticality, namely, inverse power law form for the power spectrum. Further, the long-range temporal correlations implicit to self-organized criticality can be quantified in terms of the universal characteristics  of the normal distribution. Therefore the total pattern of fluctuations of total ozone over a period of time is predictable.  

Hyperinsulinemia produces cardiac vagal withdrawal and nonuniform sympathetic activation in normal subjects

1999 ◽  
Vol 276 (1) ◽  
pp. R178-R183 ◽  
Author(s):  
Philippe Van De Borne ◽  
Martin Hausberg ◽  
Robert P. Hoffman ◽  
Allyn L. Mark ◽  
Erling A. Anderson
Keyword(s):  
High Frequency ◽  
Sympathetic Activity ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Normal Subjects ◽  
Power Spectral ◽  
Low Frequency Variability ◽  
High Frequency Variability

The exact mechanisms for the decrease in R-R interval (RRI) during acute physiological hyperinsulinemia with euglycemia are unknown. Power spectral analysis of RRI and microneurographic recordings of muscle sympathetic nerve activity (MSNA) in 16 normal subjects provided markers of autonomic control during 90-min hyperinsulinemic/euglycemic clamps. By infusing propranolol and insulin ( n = 6 subjects), we also explored the contribution of heightened cardiac sympathetic activity to the insulin-induced decrease in RRI. Slight decreases in RRI ( P < 0.001) induced by sevenfold increases in plasma insulin could not be suppressed by propranolol. Insulin increased MSNA by more than twofold ( P < 0.001), decreased the high-frequency variability of RRI ( P< 0.01), but did not affect the absolute low-frequency variability of RRI. These results suggest that reductions in cardiac vagal tone and modulation contribute at least in part to the reduction in RRI during hyperinsulinemia. Moreover, more than twofold increases in MSNA occurring concurrently with a slight and not purely sympathetically mediated tachycardia suggest regionally nonuniform increases in sympathetic activity during hyperinsulinemia in humans.

SELF-ORGANIZED CRITICALITY AND THE BARKHAUSEN EFFECT IN AMORPHOUS AND POLYCRYSTALLINE METALS

1993 ◽  
Vol 07 (01n03) ◽  
pp. 934-937 ◽  
Author(s):  
PAUL J. COTE ◽  
LAWRENCE V. MEISEL
Keyword(s):  
Power Law ◽  
Barkhausen Effect ◽  
Self Organized ◽  
Polycrystalline Metals ◽  
Power Spectral ◽  
Power Spectral Densities ◽  
Spatially Extended ◽  
Self Organized Criticality ◽  
Dissipative Dynamical Systems ◽  
Pulse Energies

An investigation of the possibility that the Barkhausen effect in amorphous and polycrystalline ferromagnets is an example of self-organized criticality is described. Since the theory of self-organized criticality was introduced by Bak, Tang, and Weisenfeld to explain the behavior of spatially extended, dissipative, dynamical systems the Barkhausen effect is a natural candidate for such a description. The data are consistent with self-organized critical behavior: the power spectral densities depend on frequency f as 1/fa and the distribution of pulse energies are well described by a power law analogous to the Gutenberg-Richter law for earthquakes. Alternative explanations for power law dependences are also presented.

scholarly journals Fractal analysis for the ULF data during the 1993 Guam earthquake to study prefracture criticality

2006 ◽  
Vol 13 (4) ◽  
pp. 409-412 ◽  
Author(s):  
Y. Ida ◽  
M. Hayakawa
Keyword(s):  
Fractal Analysis ◽  
Main Shock ◽  
Epicentral Distance ◽  
Sense Of Self ◽  
Low Frequency ◽  
Large Earthquake ◽  
Self Organized ◽  
Self Organized Criticality ◽  
Electromagnetic Signature

Abstract. An extremely large earthquake (with magnitude of 8.2) happened on 8 August 1993 near the Guam island, and ultra-low-frequency (ULF) (frequency less than 1 Hz) electromagnetic fields were measured by 3-axis induction magnetometers at an observing station (with the epicentral distance of 65 km) with sampling frequency of 1 Hz. In order to study electromagnetic signature of prefracture criticality, we have undertaken the fractal (mono-fractal) analysis by means of the Higuchi's method for the ULF data during the 1993 Guam earthquake. Then, it is found that the fractal dimension exhibits five maxima 99, 75, 52, 21, and 9–4 days before the earthquake main shock, which suggests the ULF electromagnetic signature of nonlinear evolution (in the sense of self-organized criticality) taking place in the lithosphere just before the 1993 large Guam earthquake. That is, there take place step-like changes in the lithosphere during the long-term of the order of several months before the main shock.

Self-organized criticality revisited: non-local transport by turbulent amplification

2015 ◽  
Vol 81 (6) ◽  
Author(s):  
A. V. Milovanov ◽  
J. J. Rasmussen
Keyword(s):  
Real Space ◽  
Magnetized Plasma ◽  
Tokamak Plasma ◽  
Growth Time ◽  
Strong Nonlinearity ◽  
Inverse Cascade ◽  
Self Organized ◽  
Self Organized Criticality ◽  
Non Local ◽  
Local Transport

We revise the applications of self-organized criticality (SOC) as a paradigmatic model for tokamak plasma turbulence. The work, presented here, is built around the idea that some systems do not develop a pure critical state associable with SOC, since their dynamical evolution involves as a competing key factor an inverse cascade of the energy in reciprocal space. Then relaxation of slowly increasing stresses will give rise to intermittent bursts of transport in real space and outstanding transport events beyond the range of applicability of the ‘conventional’ SOC. Also, we are concerned with the causes and origins of non-local transport in magnetized plasma, and show that this type of transport occurs naturally in self-consistent strong turbulence via a complexity coupling to the inverse cascade. We expect these coupling phenomena to occur in the parameter range of strong nonlinearity and time scale separation when the Rhines time in the system is small compared with the instability growth time.

scholarly journals Generation of X-Ray Fluctuations in X-Ray Binaries

1996 ◽  
Vol 158 ◽  
pp. 359-362
Author(s):  
S. Mineshige ◽  
M. Takeuchi ◽  
H. Negoro
Keyword(s):  
Accretion Disks ◽  
Mass Density ◽  
Temporal Distribution ◽  
Critical Value ◽  
Short Term ◽  
X Ray ◽  
Self Organized ◽  
Power Spectral ◽  
Self Organized Criticality ◽  
X Ray Binaries

AbstractShort-term aperiodic fluctuations with 1/f-like power spectral density (PSD), where f is the frequency, are characteristics of X-ray radiation from X-ray binaries. To investigate a mechanism creating fluctuations, we construct a cellular-automaton model for accretion disks based on the concept of self organized criticality (SOC). In this model, mass accretion takes place either by an avalanche triggered when the local mass density exceeds some critical value, or by a gradual diffusion occurring regardless of the critical condition. With this model, we can reproduce the observational PSD, the distributions of peak intensities of X-ray shots, and non-random temporal distribution of the shots. Possible accretion disk models producing l/f-like X-ray fluctuations are discussed. We conclude that such disks are likely to be advection dominated.

Evidence of enhanced self-organized criticality (SOC) dynamics during the radially non-local transient transport in the HL-2A tokamak

2015 ◽  
Vol 55 (11) ◽  
pp. 113010 ◽  
Author(s):  
O. Pan ◽  
Y. Xu ◽  
C. Hidalgo ◽  
W.L. Zhong ◽  
Z.B. Shi ◽  
...  
Keyword(s):  
Transient Transport ◽  
Self Organized ◽  
Self Organized Criticality ◽  
Non Local

scholarly journals Low frequency 1/<i>f</i>-like fluctuations of the AE-index as a possible manifestation of self-organized criticality in the magnetosphere

1998 ◽  
Vol 16 (12) ◽  
pp. 1580-1588 ◽  
Author(s):  
V. M. Uritsky ◽  
M. I. Pudovkin
Keyword(s):  
Solar Wind ◽  
Power Spectrum ◽  
Low Frequency ◽  
Solar Wind Plasma ◽  
Mhd Waves ◽  
Current Layer ◽  
Sandpile Model ◽  
Self Organized ◽  
Ae Index ◽  
Self Organized Criticality

Abstract. Low frequency stochastic variations of the geomagnetic AE-index characterized by 1/f b-like power spectrum (where f is a frequency) are studied. Based on the analysis of experimental data we show that the Bz-component of IMF, velocity of solar wind plasma, and the coupling function of Akasofu are insufficient factors to explain these behaviors of the AE-index together with the 1/f b fluctuations of geomagnetic intensity. The effect of self-organized criticality (SOC) is proposed as an internal mechanism to generate 1/f b fluctuations in the magnetosphere. It is suggested that localized spatially current instabilities, developing in the magnetospheric tail at the initial substorm phase can be considered as SOC avalanches or dynamic clusters, superposition of which leads to the 1/f b fluctuations of macroscopic characteristics in the system. Using the sandpile model of SOC, we undertake numerical modeling of space-localized and global disturbances of magnetospheric current layer. Qualitative conformity between the disturbed dynamics of self-organized critical state of the model and the main phases of real magnetospheric substorm development is demonstrated. It is also shown that power spectrum of sandpile model fluctuations controlled by real solar wind parameters reproduces all distinctive spectral features of the AE fluctuations.Key words. Magnetospheric physics (MHD waves and instabilities; solar wind · magnetosphere interactions; storms and substroms).

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