Dynamics of Dissolved Carbon in the Mainstem of the Lena River in July 2017

Doklady Earth Sciences - The dynamics of dissolved carbon forms in the waters of the mainstem of the Lena River from the middle reaches (the city of Yakutsk) to the nearshore zone of the Laptev Sea...     

Thermal properties of ice and of different types of open surface in the Antarctic Peninsula area

Results are considered of measurements of the temperature regime and albedo of different surfaces typical of polar regions. The measurements were carried out at King George Island, where, in summer, surfaces with different reflectivities and thermal properties are free of snow. Also, snow fields and ice with different morphometric properties persist during the whole summer. Tables of characteristic values of albedo and temperature of different surfaces and parametric relationships between albedo and temperature are presented. One of the important results is an improved interpretation of satellite images with low and medium resolution, which is impossible without detailed information on reflectivity of different surfaces.     

Zoning and sectoriality of the florencite and xenotime group minerals from quartz veins,the Subpolar Urals

A detailed study of the florencite and xenotime assemblage from quartz veins of Au-REE occurrences in the Subpolar Urals allowed the REE fractionation and distribution of REE mixtures in the crystal structure to be characterized. In minerals of selective composition, isomorphic mixtures of LREE and HREE are divided into lanthanum La_sg (La-Pr) and samarium Sm_sg (Nd-Eu) subgroups in florencite and gadolinium Gd_sg (Gd-Dy) and ytterbium Yb_sg (Ho-Lu) subgroups in xenotime. Concentrations of elements from these subgroups are inversely proportional to each other. Each florencite or xenotime crystal is characterized by several mineral varieties: xenotime-(Y) and Gd-bearing xenotime-(Y), florencite-(Sm), -(Nd), and -(Ce); they are selectively distributed by growth zones and pyramids of the crystal with formation of direct and inverse zoning. In both cases, cores of the crystals are enriched in HREE. The correlation between REEs, Y, and such trace elements as As, S, Ca, Sr, U, and Sc is established. REE deportment is considered in minerals formed as products of primary crystallization and hydrothermal redeposition. The REE fractionation is interpreted in terms of quantum mechanics.     

Field studies of variation scales of gravitational capillary waves and near-water wind in the Black Sea shelf area

In this study we present the results of data processing from the 2004 Gelendzhik Bay expedition on the Akvanavt research vessel. The data were processed using the method of wavelet analysis. We found an emerging kilometer-scale variation in the surface heaving and near-water wave over the shelf area. This effect was shown to be possibly caused by the inhomogeneity of current in the depth-drop area.     

Air—Surface Turbulent Heat Exchange in the Antarctic Coastal Zone Derived from Instrumental Observations

The results of direct measurements of turbulent fluxes at Bellingshausen station (the Antarctic) in the summer of 2002, 2003, 2007, and 2009 are considered. The features of energy exchange are studied for these seasons. The interannual and intraseasonal variability of energy exchange characteristics is investigated. It is found that heat fluxes depend on the surface state and on the wind direction. Also, as a rule, they have a clear diurnal course with negative or near-zero values at night and with positive values in the daytime, when intensive convective fluxes are observed over open ground. The momentum flux is defined by the wind direction and wind speed and by stratification conditions. The main factors affecting energy exchange between the atmosphere and the surface in the Antarctic coastal zone are synoptic conditions and the surface state (snowless season duration and moss cover presence).     

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.     

Features of Wind Wave–Induced Turbulence in Water According to Measurements in a Wind-Wave Tank

Izvestiya, Atmospheric and Oceanic Physics - Three velocity components ui (i = x, y, z) have been measured in a wind-wave tank at three levels in water in the presence of wind waves. The degree of...