New results on large-scale structures

A new version of the magnetic-tape catalog of ABELL clusters of galaxies is used to obtain redshift estimators and to generate two samples of clusters. A procedure for searching for superclusters of galaxies is applied and the results are given in tabular and graphic form. For a lmited homogeneous sample (distance 60–275 Mpc, galactic latitude B > 35°), 12 multiplets, having member clusters with known redshifts, are found. It is shown that the spatial covariance function for rich clusters has the form ξ = (r₀/r)γ with r₀ = 22.4 ± 1.8 Mpc and γ = 1.90 ± 0.25 for 3 Mpc ≲ r ≲ 80 Mpc.     

New observations and transit solutions of the inflated exoplanets HAT-P-40b and HAT-P-51b

We present high-precision photometric observations of the transiting exoplanets HAT-P-40 b and HAT-P-51 b by the Rozhen 2-m telescope.The newly-observed transit of HAT-P-40 b is the first one with a complete curve.The orbital periods of the two targets were improved.We modeled the observed transits and found bigger stellar radii than those derived from the stellar models.The planet radii of HATP-40 b and HAT-P-51 b obtained from our transit solutions are bigger than the values calculated by the empirical relations for Jupiter-mass and Saturn-mass planets respectively.Their values reveal the highlyinflated nature of the two targets,especially that of HAT-P-51 b.We established that the best transit solutions correspond to a quadratic limb-darkening law.The fitted limb-darkening coefficients of HAT-P-40 are close to the theoretical ones while those of HAT-P-51 are a little different.The precise astrometric Gaia distances of the two targets are smaller by 6%–7%than the calculated values from the stellar models.We propose the Gaia distances to be used for improvement of the stellar models as well as for more reliable calculation of the parameters of the known exoplanets.     

Fluidized mixtures of magma and rock in a late Caledonian breccia dyke and associated breccia pipes in Appin,Scotland

This paper describes an unusual occurrence of igneous material as clasts in dyke and pipe breccias associated with late Caledonian minor intrusions. It is shown that the clasts were in a plastic condition when incorporated into the breccia rock. These igneous clasts were derived from magma disrupted at depth and then transported into the fluidized breccia columns where they were mixed with large numbers of clasts derived from the quartzite wall-rocks. Textures and planar fabrics developed during collapse of the fluidized system are described and shown to be separable from the later compaction associated with extensive pressure solution of the fine matrix. Most Caledonian breccia pipes lack igneous clasts and it is considered that this group of breccias represent the rarely-preserved boundary zone between active magma and breccia systems.     

Intense turbulent convection in a horizontal plane liquid layer

Direct numerical simulation of turbulent convection in a horizontal liquid layer heated from below is performed within the framework of the nonstationary Navier—Stokes equations with the use of the Bubnov—Galerkin method. The main attention is given to calculations for superhigh supercriticalities. Computational burden is reduced by the use of the splitting method at each step of integration. Previously, the smallness of the residual arising from substitution of simulated results into the initial system of equations is demonstrated and the residual’s dependence on the number of reference functions and supercriticality is considered. A good agreement of the results obtained with the use of different numerical implementations of the Bubnov—Galerkin procedure is shown, in particular, for the stochastic processes corresponding to a low supercriticality and appearing with the formation of strange attractors close to a Mobius strip. The calculations were carried out for a wide range of supercriticality (from 1 to 34000). It is shown that simulations and experiment are in good qualitative agreement.     

Negative correlations of variations in near-water wind and surface wind waves

The relationship between the intensity of surface wind waves and near-water wind is analyzed. The data of measuring wind waves and near-water wind under natural conditions in the Black Sea (July 2004) and Norwegian Sea (June 2003, 16th cruise of the R/V Akademik Sergei Vavilov) are used. A phenomenon of negative correlations has been found between the intensity of wind waves and near-water wind in regions of substantial restructuring of wind waves in the field of inhomogeneous flows: wind-wave amplification during wind decay and vice versa. Examples of such observations are presented, a theoretical model is constructed for the observed phenomenon, and a good agreement is obtained between theory and experiment.     

Influence of chemical composition and microstructure on the hygroscopic growth of pyrogenic aerosol

The hygroscopic properties of a model smoke aerosol series including ammonium sulfate, levoglucosan, and oxalic and humic acids were investigated. The condensation growth of particles and the relative humidity of direct and inverse particle-droplet phase transitions were measured with a tandem differential mobility analyzer. The data were obtained in the range of relative humidity from 4 to 95% at 298 K. Experimental growth factors were compared to the results of Koehler theory by using contemporary models of water activity in particles. It was shown that the hygroscopic properties of the aerosols were substantially different from the hygroscopic properties of the corresponding bulk phases. It was found that a complex microstructure of nanoparticles resulted in excess volume absorption of water, in some cases causing their full deliquescence at lower relative humidities than in macrosystems of identical composition. From the measurement data, a parametrization of hygroscopic particle growth was performed. The results of parametrization can be used to construct refined models of a smoke aerosol.     

Physical modeling of long-range infrasonic propagation in the atmosphere

The results of experiments on the physical modeling of long-range infrasonic propagation in the atmosphere are given. Such modeling is based on the possible coincidence between the forms of the vertical profiles of the effective sound speed stratification in the atmospheric boundary layer (between 0 and 600 m for the case under consideration) and in the atmosphere as a whole (from the land surface up to thermospheric heights (about 150 km)). The source of acoustic pulses was an oscillator of detonation type. Owing to the detonation of a gas mixture of air (or oxygen) and propane, this generator was capable of producing short, powerful (the maximum acoustic pressure was on the order of 30 to 60 Pa at a distance of 50 to 100 m from the oscillator), and sufficiently stable acoustic pulses with a spectral maximum at frequencies of 40 to 60 Hz and a pulsing period of 20 to 30 s. The sites of acoustic-signal recording were located at different distances (up to 6.5 km) from the source and in different azimuthal directions. The temperature and wind stratifications were monitored in real time during the experiments with an acoustic locator—a sodar—and a temperature profiler. The data on the physical modeling of long-range sound propagation in the atmosphere are analyzed to verify the physical and mathematical models of predicting acoustic fields in the inhomogeneous moving atmosphere on the basis of the parabolic equation and the method of normal waves. A satisfactory agreement between calculated and experimental data is obtained. One more task was to compare the theoretical relations between variations in the azimuths and angles of tilting of sound rays about the horizon and the parameters of anisotropic turbulence in the lower troposphere and stratosphere with the experimental data. A theoretical interpretation of the experimental results is proposed on the basis of the theory of anisotropic turbulence in the atmosphere. The theoretical and experimental results are compared, and a satisfactory agreement between these results is noted.     

Organic matter of the North Atlantic

The areas that we studied in the North Atlantic (53 and 60°N) and in the Labrador Sea in the summer were characterized by a wide variability of the concentrations of dissolved and particulate organic matter and its elemental composition both in the surface and in the deep waters. The concentrations of dissolved and particulate C_org varied within 69–360 μM and 0.7–25.6 μM, respectively; the N_org and P_org contents varied within 1.4–22.2 μM and 0.02–0.86 μM, respectively. The maximal concentrations were registered in the photic layer and in the zones of mixing between the waters of different genesis. The particulate matter contribution to the total organic matter (OM) content varied from 0.5 to 15.4%. The waters of the photic layer contained more particulate C_org than those of the near-bottom layer. The values of the C/N molar ratios from the surface to the bottom over the entire aquatic area surveyed varied 5-to 6-fold; at that, the values of the C/P molar ratios varied more than tenfold. In the most productive waters, the values of the C/N ratios were close to the Redfield ratios (6–10). The values of the C/P molar ratios varied from 160 in the photic layer to 4831 in the deep waters. The pronounced non-uniformity in the spatial distribution of the OM and its elemental composition is caused not only by the penetration of the waters of different origins but also by the changes in the microplankton metabolism under mixing of these waters.