Stratwarm Effects in the Ionospheric D Region Wind Field

An analysis is made of the wind field structure in the strato-thermosphere over Eastern Siberia during the winter stratwarms of 1975-1977. It is found that coupling between dynamical processes in the stratosphere and lower thermosphere is effected through changes of the temperature regime of the atmosphere. The circulation regime both in the stratosphere and lower thermosphere depends on location of the source of perturbations that cause stratospheric warmings. The effect of warming-induced perturbations on the dynamics of above- and underlying layers and the meridional extent of the processes are determined by the altitude and region where anti-cyclones originate. In conditions of a warmer stratosphere, there is a considerable loss of wind stability in the ionospheric D-region. A time delay of 1 to 2 days of lower-thermosphere processes is found to occur with respect to stratospheric processes of temperature variation at 30 mb level

The Planetary Wave Activity in Temperatures of the Stratosphere, Mesosphere and in Critical Frequencies of Ionospheric F2 Layer

A large body of experimental evidence lends credit to the existence of a close relationship between ionospheric parameters and the underlying atmosphere. Vertical-incidence ionospheric sounding data and temperature measurements at stratospheric (30 km) and mesospheric (80 km) heights have been used in investigating the interrelation between the occurrence of fluctuations with periods of planetary waves in temperature variations at different heights and in F2 layer critical frequency variations (foF2) under low solar activity conditions for the time interval 2006-2007. The distinctive characteristics of the manifestation of common periodicities of the wave structures under consideration are discussed. The statistically significant periods of stratospheric and mesospheric temperature fluctuations vary from 11 to 49 days, whereas foF2 periodograms show higher-frequency fluctuations with periods of 5, 8, 9, and 10 days. The study revealed a similarity between periodic structures for the variations in the parameters involved

The crystal structure of fedotovite, K2Cu30(SO4) 3

Abstract The crystal structure of fcdotovite, K1CU30(S04h has been determined, space group C2/e, a 19.037(6), h 9.479(2), e 14.231(5) A,~1 11.04(3t, Z = 8, Dx = 3.09 g/cm3. The main units of the fedotovite structure are formed around two additional oxygen atoms and consist of edge-sharing [OCU4J tetrahedra and four [S04J tetrahedra attached to them. The units are further connected by two [S04J tetrahedra, building distinct layers parallel to the yz plane. These layers are interconnected by potassium atoms. In the fedotovite structure, the three kinds of copper atoms are fivefold (4 + 1) coordinated to oxygen atoms with a strong Jahn-Teller effect. The coordination polyhedra of Cui and Cu2 atoms are distorted and flattened orthorhombic pyramids with Cu-O distances varying from 1.912 to 2.333 A,. the sixth neighbour of the both atoms is the copper atom lying at 2.975 and 2.981 Afor Cu2 and Cui respectively. The coordination environment of the Cu3 atom is a distorted elongated orthorhombic pyramid with four Cu-O distances from 1.943 to 1.961 A, a fifth at 2.558 A, and further sixth and seventh neighbours (oxygen and copper atoms) at 2.809 and 2.806 A, respectively

Mesospheric, lower thermospheric dynamics and external forcing effects: A review

7-36A review is presented on some of the most important experimental results and models obtained by international scientific community during last decade for the mesospheric and lower thermospheric dynamics (mean winds, planetary waves, tides and internal gravity waves). In addition to climatological features, the external forcing – the coupling from below (stratosphere) and possible influence of solar and geomagnetic activity on the dynamical processes at this region are presented

The Ashes of 2017 from the Klyuchevskoy and Kambalnyy Volcanoes: A Comparative Mineralogical-Geochemical Analysis

The results of the mineralogical and geochemical study of the ash of the Klyuchevskoy and Kambalnyy volcanoes located in different geological conditions (Klyuchevskoy – Central Kamchatskaya Depression, Kambalnyy - Southeast end Eastern Kamchatka Volcanic Ridge) were obtained in 2017, and allowed making following conclusions. The investigated ashes differ somewhat in chemical composition: the Klyuchevskoy volcano ash is close to andesibasalts, but that from Kambalnyy is close to andesites. According to the normative-mineral composition, they are composed of 65–87% basic plagioclases, 3–22% quartz, 6.5–14% Mg-Fe-Ca silicates (olivine, pyroxene, probably hornblende). In this case, the ashes from the volcano Kambalnyy are characterized by more acidic composition of plagioclase and higher content of quartz.  The accessory minerals found in the ashes are presented by spinels (Ulviya magnetite, magnetite, and chromite), ilmenite, rutile, apatite, zircon, pyrite and native metallic-phase (Al, Cu, Fe). Pelitic (silty) fractions are enriched in quartz, but impoverished in Mg-Fe-Ca silicates. As a small admixture in the ash of the Cumulus volcano, titanite, andradite, kaolinite and gypsum are inherently resurgent. The fact of detecting the filamentous forms of abiogenic condensed organopolymer substance of CNO composition in the investigated ashes is of particular importance. It should be noted that, according to the isotope composition of carbon, these formations are identical to similar threads and particles identified in products of modern volcanism in the Kamchatka-Philippine island arc megabelt. Moreover, the analysis showed the presence in the ashes of the Kliuchevskoy and Kambalnyy volcanoes of the carbon substance, which carbon isotopic composition practically coincides with that in the organic filaments. Ashes contain 50 microelements divided into five groups: alkaline and alkaline earth, hydrolyzed, lanthanides, chalcoceridophiles, semi- and non-metals. The analysis leads to the conclusion that the predominantly plagioclase containing ash from both volcanoes show a 75% geochemical similarity to the deep source matter. According to the shape of the curves of chondritotropic concentrations of lanthanides, the ashes from both volcanoes are close to the basaltic lavas of TTI-50. The insignificance of the Eu anomaly on the most curves and the apparent moderate differentiation of the lanthanides indicate that the fractionation of plagioclases in the primary melts and the significant realization of the fractionation of olivine and pyroxenes are weak. Based on the granulometric and morphological homogeneity of particles and the presence of a significant content of fresh volcanic glass in ash from both volcanoes, it can be assumed that in both cases the ashes were predominantly or largely melt-formed, and primarily associated with deep magmatic chambers. It is supposed that the process of slow rise of magmatic melts with their fractionation and gravitational stratification into the lower Mg-Fe-silicate and upper aluminosilicate parts took place. Last eruption of the aluminosilicate substrate occurred in the ash form. Because of the viscosity and tendency to quick solidification, aluminum silicate magmatic magma plugged the channel thus preventing the eruption of the lava Hawaiian type