Self-similar and self-affine structures in the observational data on solar activity

2005 ◽  
Vol 24 (2) ◽  
pp. 93-99 ◽  
Author(s):  
O. Chumak
Keyword(s):  
Solar Activity ◽  
Observational Data ◽  
Affine Structures ◽  
Self Similar

scholarly journals Crossover from Self-Similar to Self-Affine Structures in Percolation

1994 ◽  
Vol 26 (6) ◽  
pp. 413-418 ◽  
Author(s):  
E Frey ◽  
U. C Täuber ◽  
F Schwabl
Keyword(s):  
Affine Structures ◽  
Self Similar

SCALING OF FLOW DISTANCE IN RANDOM SELF-SIMILAR CHANNEL NETWORKS

Fractals ◽  
2005 ◽  
Vol 13 (04) ◽  
pp. 265-282 ◽  
Author(s):  
BRENT M. TROUTMAN
Keyword(s):  
Drainage Basin ◽  
Empirical Studies ◽  
Rooted Tree ◽  
Network Size ◽  
Channel Networks ◽  
Tree Graphs ◽  
Affine Structures ◽  
Self Similar ◽  
Function Number ◽  
Behavior Characteristic

Natural river channel networks have been shown in empirical studies to exhibit power-law scaling behavior characteristic of self-similar and self-affine structures. Of particular interest is to describe how the distribution of distance to the outlet changes as a function of network size. In this paper, networks are modeled as random self-similar rooted tree graphs and scaling of distance to the root is studied using methods in stochastic branching theory. In particular, the asymptotic expectation of the width function (number of nodes as a function of distance to the outlet) is derived under conditions on the replacement generators. It is demonstrated further that the branching number describing rate of growth of node distance to the outlet is identical to the length ratio under a Horton-Strahler ordering scheme as order gets large, again under certain restrictions on the generators. These results are discussed in relation to drainage basin allometry and an application to an actual drainage network is presented.

Solar Activity in the Corona

1981 ◽  
Vol 4 (2) ◽  
pp. 132-138 ◽  
Author(s):  
D. J. McLean
Keyword(s):  
Solar Activity ◽  
Internal Structure ◽  
Observational Data ◽  
Radio Astronomy ◽  
Solar Radio ◽  
The Sun ◽  
The Core ◽  
Solar Radio Astronomy

When I began my studies of solar radio astronomy, Dr J. L. Pawsey, who then led the radio astronomy group in the Division of Radiophysics, CSIRO, explained to me that the internal structure of the Sun was ‘well understood’, thanks to a lack of conflicting observational data, but that for the observable layers of the Sun, the photosphere, chromosphere and corona, a great many mysteries remained. I am sure that he would have been amused by the recent discovery that there are not enough neutrons coming from the core of the Sun. I shall devote most of my talk to matters about which we are fairly certain, but often I will only be able to give part of the story because the details have not yet emerged from the wealth of solar mysteries.

scholarly journals Modelling grand minima of solar activity using a flux transport dynamo model

2012 ◽  
Vol 8 (S294) ◽  
pp. 433-438
Author(s):  
Bidya Binay Karak ◽  
Arnab Rai Choudhuri
Keyword(s):  
Solar Activity ◽  
Observational Data ◽  
Meridional Circulation ◽  
Sunspot Cycle ◽  
Maunder Minimum ◽  
Dynamo Model ◽  
Poloidal Field ◽  
Flux Transport ◽  
Grand Minima

AbstractThe occurrence of grand minima like the Maunder minimum is an intriguing aspect of the sunspot cycle. We use the flux transport dynamo model to explain the grand minima, showing that they arise when either the poloidal field or the meridional circulation falls to a sufficiently low value due to fluctuations. Assuming these fluctuations to be Gaussian and determining the various parameters from the data of the last 28 cycles, we carry on a dynamo simulation with both these fluctuations. The results are remarkably close to the observational data.

Current status of special planetary and lunar theories and ephemerides

1966 ◽  
Vol 25 ◽  
pp. 266-267
Author(s):  
R. L. Duncombe
Keyword(s):  
Observational Data ◽  
Current Status ◽  
Numerical Errors

An examination of some specialized lunar and planetary ephemerides has revealed inconsistencies in the adopted planetary masses, the presence of non-gravitational terms, and some outright numerical errors. They should be considered of temporary usefulness only, subject to subsequent amendment as required for the interpretation of observational data.

July 11, 1991 Eclipse Corona Photometry by the Results of Electropolarimetric and CCD-Matrix Observations

1994 ◽  
Vol 144 ◽  
pp. 567-569
Author(s):  
V. Kulidzanishvili ◽  
D. Georgobiani
Keyword(s):  
Solar Corona ◽  
Observational Data ◽  
Solar Limb ◽  
Ccd Matrix

AbstractThe observational data of July 11, 1991 eclipse solar corona obtained by both electropolarimeter (EP) and CCD-matrix were processed. Using these data, the solar corona photometry was carried out. The results of EP data are compared with the ones of CCD data. It must be noted here that the CCD data give us only characteristics of the inner corona, while the EP data show the features of both the inner and middle corona up to 4R⊙. Standard flattening indexϵis evaluated from both data. The dependence of the flattening index on the distance from the solar limb is investigated. The isophotes in Na and Ca lines are plotted. Based on these data some ideas and conclusions on the type of the solar corona are presented.

Influence of Magnetic Fields on Solar Hydrodynamics: Experimental Results

1977 ◽  
Vol 36 ◽  
pp. 143-180 ◽  
Author(s):  
J.O. Stenflo
Keyword(s):  
Solar Activity ◽  
Energy Balance ◽  
Magnetic Fields ◽  
Solar Atmosphere ◽  
General Problem ◽  
Solar Rotation ◽  
Active Regions ◽  
Physical Conditions ◽  
Dynamic Phenomena

It is well-known that solar activity is basically caused by the Interaction of magnetic fields with convection and solar rotation, resulting in a great variety of dynamic phenomena, like flares, surges, sunspots, prominences, etc. Many conferences have been devoted to solar activity, including the role of magnetic fields. Similar attention has not been paid to the role of magnetic fields for the overall dynamics and energy balance of the solar atmosphere, related to the general problem of chromospheric and coronal heating. To penetrate this problem we have to focus our attention more on the physical conditions in the ‘quiet’ regions than on the conspicuous phenomena in active regions.

Prominences and Solar Activity

1979 ◽  
Vol 44 ◽  
pp. 357-372
Author(s):  
Z. Švestka
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
List Type ◽  
Type Number ◽  
Flare Loops ◽  
Filament Activation

The following subjects were discussed:(1)Filament activation(2)Post-flare loops.(3)Surges and sprays.(4)Coronal transients.(5)Disk vs. limb observations.(6)Solar cycle variations of prominence occurrence.(7)Active prominences patrol service.Of all these items, (1) and (2) were discussed in most detail and we also pay most attention to them in this report. Items (3) and (4) did not bring anything new when compared with the earlier invited presentations given by RUST and ZIRIN and therefore, we omit them.

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