Quasi-Biennial Oscillations of Global Solar-Activity Indices

Quasi-biennial oscillations of solar activity are investigated using several global indices. The Singular Spectrum Analysis is used to separate out and study quasi-biennial oscillations; this method is one of the modifications of the main components method. The principal components of the solar cycle are stable 11-year, secular, and quasi-biennial variations. The periods and shapes of individual variations in each quasi-biennial train depend on the length and power of the particular 11-year cycle.     

Predictions for the clustering properties of the Lyman-alpha forest – I. One-point statistics

We present predictions for the one-point probability distribution and cumulants of the transmitted QSO flux in the high redshift Lyman- α forest. We make use of the correlation between the Lyman- α optical depth and the underlying matter density predicted by gravitational instability theory and seen in numerical hydrodynamic simulations. We have modelled the growth of matter fluctuations using the non-linear shear‐free dynamics, an approximation which reproduces well the results of perturbation theory for the cumulants in the linear and weakly non-linear clustering regime. As high matter overdensities tend to saturate in spectra, the statistics of the flux distribution are dominated by weakly non-linear overdensities. As a result, our analytic approach can produce accurate predictions, when tested against N -body simulation results, even when the underlying matter field has root-mean-square fluctuations larger than unity. Our treatment can be applied to either Gaussian or non-Gaussian initial conditions. Here we concentrate on the former case, but also include a study of a specific non-Gaussian model. We discuss how the methods and predictions we present can be used as a tool to study the generic clustering properties of the Lyman- α forest at high redshift. With such an approach, rather than concentrating on simulating specific cosmological models, we may be in a position to directly test our assumptions for the Gaussian nature of the initial conditions, and the gravitational instability origin of structure itself. In a separate paper we present results for two-point statistics.     

Power law relating 10.7 cm flux to sunspot number

To investigate the relation between observations of the 10.7 cm flux and the international sunspot number so that a physical unit may be ascribed to historical records, both polynomial and power law models are developed giving the radio flux as a function of sunspot number and vice versa. Bayesian data analysis is used to estimate the model parameters and to discriminate between the models. The effect on the parameter uncertainty and on the relative evidence of normalizing the measure of fit is investigated. The power law giving flux as a function of sunspot number is found to be the most plausible model and may be used to estimate the radio flux from historical sunspot observations.     

U–Pb zircon age of the base of the Ediacaran System at the southern margin of the Qinling Orogen

Global abrupt climate change from Marinoan snowball Earth to greenhouse Earth, recorded as cap carbonate overlain on diamictite, had shed the first light on Cambrian bio-radiation. The most documented cap carbonate sections are typical with comprehensive δ¹³C negative values and ubiquitous sedimentary structures, such as tepee-like, sheet-crack etc., which are associated with successive glacial eustatic variation caused by isostatic rebound in shallow-water facies. Here we report a deep-water basinal cap carbonate section with strong negative δ¹³C values in the southern margin of the Qinling Orogen, Heyu, Chengkou County, Chongqing in China, which consists of massive dolostone with abundant carbonaceous laminae. However, it lacks the sedimentary structure as mentioned above and is overlain by thin-bedded silicious shales and cherts. A K-bentonite bed was discovered within the base of cap carbonates, about 0.7 m above the top of the Marinoan diamictite. Magmatic zircons that were separated from the K-bentonite bed yield a SIMS concordia U–Pb age of 634.1 ± 1.9 Ma (1σ, MSWD_CE = 0.31, Probability_CE = 1.000, n = 20). The age is in good agreement with previously reported TIMS U–Pb ages for the termination of Marinoan glaciation and provides a geochronological constraint for the Ediacaran successions in the Qinling Orogen.     

The eSTAR network – agent architectures for astronomy

The eSTAR Project uses intelligent agent technologies to carry out resource discovery, submit observation requests and analyze the reduced data returned from a meta‐network of robotic telescopes. Linking ground based telescopes with astronomical satellites, and using the emerging field of intelligent agent architectures to provide crucial autonomous decision making in software, the project has succeeded in combining data archives and research class telescopes, along with distributed computing nodes, to build an ad‐hoc peer‐to‐peer heterogeneous network of resources. We present the current operations paradigm of the eSTAR network and describe the direction in which the project intends to develop over the next few years. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Generalized thermodynamics uncertainty and (anti) de Sitter space

The derivation of the thermodynamics uncertainty to anti de Sitter space-time is carried out. The entropy of anti de Sitter space is obtained. Furthermore, for first time, the electromagnetic signal related to the Hawking radiation is suggested to be calculated which may be a key factor in realizing black holes in both cosmos and lab.     

The Shiveluch Volcanic Massif,Kamchatka: Stages in the Evolution of a Magmatic System: Results of Geochronological and Thermobarogeochemical Studies

It is shown that Shiveluch, which consists of several volcanic edifices that stand in one area and in part overlie each other, is a long-lived volcanic massif with a complex structure. The available data on the morphology of the edifice, age, rock compositions, primary melts, and types of eruptive activity were used to identify structurally-temporal units (STUs) in the Shiveluch volcanic massif. It was found that the generation of different-age STUs was due to the activity of at least four magma chambers with different parameters. The durations of the individual chambers were determined. The activities of these chambers were initiated and came to an end nearly instantaneously because of major collapse episodes in the edifice of the massif due to high-magnitude earthquakes.     

Synchronization trends and rhythms of multifractal parameters of the field of low-frequency microseisms

The field of low-frequency microseisms is investigated with the use of data from 83 stations of the F-net broadband network in Japan over the period from the beginning of 1997 through June 2008. Vertical components with a sampling step of 1 s are used for analysis, as well as signals with a sampling step of 1 min obtained from the initial data by averaging and thinning. Long-period regularities of changes in the singularity spectrum support width Δα and the generalized Hurst exponent α* for the field of low-frequency microseisms were revealed by estimating multifractal singularity spectra in consecutive time windows 30 min long for 1-s data and 24 hour long for 1-min data. The average value of the parameter α* for 1-s data significantly decreased before the Hokkaido earthquake of September 25, 2003 (M = 8.3), and was not restored subsequently to its previous level. Prior to September 2003, 1-min data on α* variations experienced strong annual changes, which completely ceased afterwards. Both these effects are interpreted as an increase in the degree of synchronization of microseismic noise on Japan’s islands after the September 25, 2003, earthquake. This hypothesis is also supported by estimates of the measures of correlation and spectral coherence between variations in the average values of Δα and α* calculated for 1-min data inside five spatial clusters of stations from consecutive time fragments two months long. Based on the well-known statement of the theory of catastrophes that synchronization is one of the flags of an approaching catastrophe, it was suggested that the Hokkaido event could be a foreshock of an even stronger earthquake nucleating in the region of Japan’s islands.