Spatial and temporal variability and monitoring of hydrophysical fields of the Black Sea

As part of the Russian-Ukrainian program “The Black Sea as a Simulation Model of the Ocean,” the monitoring of the marine environment is considered using modern measuring systems. On the basis of historical and contemporary observation data, we estimate the spatial and temporal scales of dominant processes in the Black Sea. We describe the main measuring systems used to monitor the structure and variability of the hydrophysical fields. Examples characterizing the specific features of the Black Sea processes are presented.     

Modeling the Magnetic Anomaly of the Bosumtwi (Ghana) Complex Meteorite Crater by Taking Into Account the Impact Demagnetization and Morphological Features

Izvestiya, Physics of the Solid Earth - Abstract—The formation of impact craters on the Earth’s surface is accompanied by the effect of shock waves on rocks. The shock wave compression...     

Modeling damage and deformation in impact simulations

Abstract— Numerical modeling is a powerful tool for investigating the formation of large impact craters but is one that must be validated with observational evidence. Quantitative analysis of damage and deformation in the target surrounding an impact event provides a promising means of validation for numerical models of terrestrial impact craters, particularly in cases where the final pristine crater morphology is ambiguous or unknown. In this paper, we discuss the aspects of the behavior of brittle materials important for the accurate simulation of damage and deformation surrounding an impact event and the care required to interpret the results. We demonstrate this with an example simulation of an impact into a terrestrial, granite target that produces a 10 km‐diameter transient crater. The results of the simulation are shown in terms of damage (a scalar quantity that reflects the totality of fragmentation) and plastic strain, both total plastic strain (the accumulated amount of permanent shear deformation, regardless of the sense of shear) and net plastic strain (the amount of permanent shear deformation where the sense of shear is accounted for). Damage and plastic strain are both greatest close to the impact site and decline with radial distance. However, the reversal in flow patterns from the downward and outward excavation flow to the inward and upward collapse flow implies that net plastic strains may be significantly lower than total plastic strains. Plastic strain in brittle rocks is very heterogeneous; however, continuum modeling requires that the deformation of the target during an impact event be described in terms of an average strain that applies over a large volume of rock (large compared to the spacing between individual zones of sliding). This paper demonstrates that model predictions of smooth average strain are entirely consistent with an actual strain concentrated along very narrow zones. Furthermore, we suggest that model predictions of total accumulated strain should correlate with observable variations in bulk density and seismic velocity.     

Sector Structure, Rotation, and Cyclic Evolution of Large-Scale Solar Magnetic Fields

Auto-correlation analysis was performed using digitized synoptic charts of photospheric magnetic fields for the past three solar activity cycles (1965–1994). The obtained correlograms were used to study the rotation and the zonal-sector structure of large-scale solar magnetic fields all over the observable region of heliolatitudes in various phases of solar activity. It is shown that the large-scale system of solar magnetic fields is rather complex and comprises at least three different systems. One is a global rigidly rotating system. It determines the cyclic variation of magnetic fields and is probably responsible for the behavior of magnetic fields in the polar zones. Another is a rigidly rotating 4-sector structure in the central (equatorial and mid-latitude) zone. The third is a differentially rotating system that determines the behavior of the LSSMF structure elements with a size of 30–60° and less. This one is the most noticeable in the central zone and absent in the polar zones. Various cyclic and rotation parameters of the three field structures are discussed.     

Ideality of fermi gases in a strong magnetic field

Brest Pedagogical Institute. Translated from Astrofizika, Vol. 31, No. 1, pp. 191–194, July–August, 1989.     

New stellar associations in M33 galaxy

Extending the numeration of Humphreys and Sandage (1980) 54 new associations are identified in the galaxy M33 by comparing the plates in theU andB system. The larger part of the associations are located in the spiral arms. The young associations are prevailing in proximity to the nucleus. A large part of the newly identified associations are connected withHii regions. Judging by the farthest associations M33 diameter is estimated 20 kpc. The associations outline two strong and two faint spiral arms up to 4 kpc away from the nucleus. Their possible behaviour is observed in the further parts.     

Ratios of the I 630.0/I 427.8 and I 557.7/I 427.8 emission intensities in auroras

More than 3800 measurements of the 630.0, 557.7, and 427.8 nm emission intensities have been statistically manipulated, and the dependences of the I ₆₃₀/I _427.8 and I _557.7/I _427.8 ratios on the I _427.8 nm emission intensity have been obtained. The I ₆₃₀/I _427.8 ratio decreases from 2 to 0.4 when the I _427.8 nm emission intensity increases from 0.1 to 3 kR. In the I _427.8 nm emission range 0.1–1.8 kR, the I _557.7/I _427.8 ratio tends to increase and takes the values 4.2–6.4. The experimental results have been confirmed by theoretical calculations. The obtained I _557.7/I _427.8 ratios suggest that the NO density at a maximum of its height profile is on the average 10⁸ cm^?3 in typical nighttime auroras.