A field experiment on modeling the impact of aerosol layers on the variability of solar insolation and meteorological characteristics of the surface layer

Described are the results of a field experiment carried out in 2010 on studying the impact of artificial aerosol formations on the solar insolation intensity and thermal characteristics of the atmospheric surface layer. The composition of the measuring equipment complex is given and the results of the experiment and its theoretical analysis are presented. It is demonstrated that the solar radiation flux decrease results in rather rapid response of the surface air layer manifesting itself in the considerable decrease in temperature and turbulent heat fluxes. The theoretical estimates corroborate the obtained experimental data. The field experiment is the continuation of researches carried out in 2008 and 2009.     

Safety assessment concept for repositories of spent nuclear materials in crystalline rocks

The methodological issues in safety assessment of repositories of spent nuclear materials (high level wastes and untreatable irradiated fuel) in crystalline rocks are discussed, and a concept of such assessment is proposed. The problem is urgent because of the need for scientific confirmation of the safety assessment procedure for such repositories in Russian territory.     

Structure of the North Kara Shelf from results of seismostratigraphic analysis

The sedimentary cover section of the North Kara Shelf had been subdivided based on extensive seismic data, and seismic correlation was carried out. The predominant role of Upper Riphean-Middle Paleozoic rocks has been corroborated. A series of relatively deepwater basins filled with primarily terrigenous fly-schoid rocks up to 7–9 km in thickness existed in the Late Riphean-Vendian at the place of the shelf. In the Cambrian, isolated basins merged into a wide and shallow-water basin as a result of the Baikalian reactivation in southeast Severnaya Zemlya and probably in Taimyr. After the pre-Ordovician hiatus, a vast sedimentation basin with a regressive section was formed on the shelf from Ordovician to Late Devonian. Shallow-water marine and near-shore carbonate and carbonate-terrigenous sequences accumulated in this basin and gave way to continental and less frequent near-shore, marine, variegated, and red beds in the Devonian. The thickness of the Ordovician-Devonian sequence reaches 6 km. Since the Mid-Carboniferous, block emergence and deep erosion of Ordovician-Devonian complexes have occurred in the north Kara shelf as a result of Hercynian events in northern Taimyr, Severnaya Zemlya, and in the southern Kara Sea. No Permian-Triassic rifts existed on the North Kara Shelf. At that time, the shelf was an area of erosion. The thickness of the Middle Carboniferous-Cretaceous sequence was insignificant and gradually increased toward Barents Sea troughs. The newly formed Svyataya Anna and Voronin troughs arose due to opening of the Eurasia Basin of the Arctic Ocean. The terrane concept has been subjected to criticism. The available data show that a large epi-Grenvillian continental block existed, and the North Kara region was part of it. Collision of the northern continent with the Paleosiberian Platform in the Late Paleozoic resulted in the formation of the Hercynian fold arc to the south of the North Kara Shelf, and an inverted orogenic arch arose at the place of shelf basin. The individual geological features that distinguish the North Kara Shelf from the Barents Sea troughs and the South Kara Syneclise are emphasized. The ancient pre-Riphean basement, a system of Late Riphean-Vendian relatively deepwater troughs and basins, Hercynian tectonic inversion, deep erosion of the most uplifted part of the arch, and significant block motions are the distinguishing features of the North Kara Shelf.     

Simulation of the Kinetics of Precipitation Formation in a Mixed-Phased Cloud

Izvestiya, Atmospheric and Oceanic Physics - A system of kinetic equations describing microphysical processes in a three-phase vapor–water–ice system is analyzed in terms of its...     

Interval Algorithm for the Planetary Problem

To calculate the dynamics of celestial bodies, we suggest the nonclassic interval algorithm based on taking into account explicitly the limitations of the resolving capacity of instrumental observation facilities. This algorithm is consistent with the correspondence principle (has a classic limit) and is a system of integer mappings of a recurrent type which is free of the effect of the round-off error accumulation. Another feature is its relative simplicity, which allowed us to make the calculations less time-consuming as compared to the classic approach. This algorithm was used to calculate the evolution of the Solar System's planetary orbits over times of about 500 million years. The calculations support the results obtained earlier by classic methods and make it possible to conclude that the suggested interval approach can be adequately applied to the planetary problem under consideration.     

T Tauri Stars

The observable characteristics of young solar-mass stars (T Tauri stars) are reviewed. Modern theoretical concepts and models of these stars are discussed briefly.     

Physicochemical Conditions of Formation of Productive Mineral Assemblages of Gold Deposits in the Taimyr–Severnaya Zemlya Orogen

Doklady Earth Sciences - The PTX parameters of the formation of gold mineralization in the Taimyr–Severnaya Zemlya orogen were established for the first time based on data from studies of...     

C, О, S,and Sr Isotope Geochemistry and Chemostratigraphy of Ordovician Sediments in the Moyero River Section,Northern Siberian Platform

The ⁸⁷Sr/⁸⁶Sr ratio in gypsum and limestones of the Ordovician section of the Moyero River decreases from the bottom upward from 0.7091?0.7095 in the Irbukli Formation (Nyaian Regional Stage, ~Lower Ordovician Tremadocian Stage) to 0.7080 in the upper part of the Dzherom Formation (Dolborian Regional Stage, ~Upper Ordovician Katian Stage), which is well consistent with biostratigraphic subdivision of the section and existing concept concerning the strontium isotope evolution of the World Ocean. The most characteristic feature of the carbon isotope curve is decrease of δ¹³С values in carbonates from weakly positive values (0.5…1.1‰) in the Irbukli Formation (Nyaian Regional Stage) to sharply negative values (–5.4...–5.8‰) in the middle part of the Kochakan Formation (top of the Kimaian Regional Stage, ~end of the Dapingian–base of the Darriwilian Stage). Increase of δ¹⁸О from 20?22‰ to 26?28‰, the negative correlation of δ¹³С and δ¹⁸О, and decrease of δ³⁴S in gypsum from 30?32‰ to 22?24‰ in this interval indicate that the ¹³С depletion of carbonates was not related to the sulfate reduction and oxidation of organic matter during diagenesis and that the negative δ¹³С excursion was of primary nature. The presence of negative δ¹³С anomalies at this stratigraphic level in Ordovician sections of the South and North America (Buggish et al., 2003; Edwards and Saltzman, 2014; McLaughlin et al., 2016) indicates the global or subglobal distribution of this event, which was possibly related to the emergence of the oldest ground vegetation. Against the general decrease of δ¹³С, the lower part of the section reveals three low-amplitude (1?2‰) positive excursions, the position of which in general confirms the existing correlation scheme of the Moyero River section with the international scale. The upper part of the section is characterized by the alternation of low-δ¹³С intervals (from–2 to–3‰) and brief positive excursions with amplitude of 0.5?1.3‰. The positive δ¹³С excursion terminating the Ordovician section of the Moyero River correlates with the δ¹³С excursion in the middle Katian Stage, while the δ¹³С excursion in the lower part of the Baksian Regional Stage correlates with the excursion marking the Katian–Sandbian boundary.     

Carbon,oxygen, and sulfur isotope compositions and model of the Silurian rock formation in northwestern Belarus

The paper describes the results of study of the Silurian clayey–carbonate rocks ranging from the Telychian Stage (Llandovery) to the Gorstian Stage (Ludlow) recovered by the Borehole Davtyuny 3k in northwestern Belarus. Rocks of the Sheinwoodian Stage demonstrate a positive excursion of δ¹³C with amplitude of 4.7‰, marking the Ireviken biotic event recorded in the global chemostratigraphic curve. Values of δ¹⁸O for the carbonate material in the studied section (25.5–29.2‰ SMOW) are close to those for Silurian rocks from the Baltic region, Scandinavia, Ukraine, Poland, and Canada. The whole section contains postsedimentary gypsum as nodules and the infilling of fissures and fenestrae. Values of δ³⁴S in gypsum (21.3–26.7‰ CDT) are close to those for the Silurian rocks on the Phanerozoic isotope plot. The formation of gypsum was related to a partial development of the supralittoral environment over the sublittoral and littoral clayey–carbonate substrate. The seawater accumulated in lowlands of the supralittoral plain after storms was intensely concentrated during arid conditions and accumulated in the clayey–carbonate sediment. The subsequent underground evaporation promoted the formation of gypsum as nodules in the unlithified sediments and the infilling of fissures and fenestrae in the lithified rocks.