Seasonal Variability in the Sedimentary Matter Flux on the Shelf of the Northern Kara Sea

Oceanology - Sedimentation rates in the northern Kara Sea between September 2019 and July 2020 were calculated from integrated monthly values for sedimentary matter, organic carbon, nitrogen, total...     

An emission layer as a gravity wave detector

A three-dimensional model is used to investigate the relations between parameters of atmospheric gravity waves (GW) and the spatial structure of O₂ atmospheric (0,0) nightglow wave perturbations observed from space. It is shown that observed perturbations may be divided into the linear and nonlinear parts. The linear perturbations appear as wavelet signatures observed at certain viewing directions. The nonlinear part of the perturbations causes an increase in all sky brightness of the O₂ atmospheric (0,0) nightglow. The model shows that at certain viewing directions the cancellation effect for waves passing through the emission layer disappears. The latter gives the opportunity to create the complete set of functions that may be used for the spectral decomposition of observed brightness field. The obtained spectrum may be interpreted in terms of the Fourier coefficients of 3D-decomposition of the temperature fluctuations induced by gravity waves just near the emission layer.     

Transport of the colloid matter of riverine runoff through estuaries

A procedure for separating the colloid component of natural waters is proposed. It was shown that this component is the main form of matter transfer in Ob River runoff, because the mass of colloid substance is two orders of magnitude higher than that of particulate matter in the outer part of the estuary. Simulation and field experiments revealed the influence of nature and concentration of organic matter on their ability to stabilize or flocculate clay particles with an increase in salinity, thus affecting the range of transfer of riverine runoff matter. It was shown that the interaction of humic acids and clay particles, as well as the increase in hydrophobic properties of a flocculant, improve flocculation efficiency. Criteria are proposed to recognize in the estuarine region areas of pronounced contribution of flocculation processes to sedimentation of fine particles. It is shown that the newly formed organic matter produced by biota under saline stress might be flocculants of fine particulate matter.     

Analysis of the variability of hydrological characteristics of the north subpolar front using the model of frontal-trapped baroclinic Rossby waves

Solutions, termed frontal-trapped Rossby waves, have been found for the long-wave equation in a model of a two-layer fluid with the frontal boundary given in the form of an exponential function. Data from a hydrological survey of a subpolar hydrological front in the vicinity of Newfoundland are analysed. A frontal-trapped wave model is shown to describe about 40% of the dispersion of the initial seawater density field. Translated by V. Puchkin.     

Hydrochemical features of boggy river sources and lakes in central European Russia

Water chemistry in deep freshwater lakes and springs, situated in boggy areas and giving rise to the majority of the Russian rivers, is considered. Those lakes and springs can serve as an important reserve of fresh drinking water.     

A layer of ozone detected in the nightside upper atmosphere of Venus

To date, ozone has only been identified in the atmospheres of Earth and Mars. This study reports the first detection of ozone in the atmosphere of Venus by the SPICAV ultraviolet instrument onboard the Venus Express spacecraft. Venusian ozone is characterized by a vertically confined and horizontally variable layer residing in the thermosphere at a mean altitude of 100 km, with local concentrations of the order of 10⁷–10⁸ molecules cm⁻³. The observed ozone concentrations are consistent with values expected for a chlorine-catalyzed destruction scheme, indicating that the key chemical reactions operating in Earth’s upper stratosphere may also operate on Venus.     

Apatite-bearing greenstone belts in Russia

The paper discusses the important and urgent problem of enlarging the mineral resources of Russia. Volcanosedimentary complexes of greenstone belts are suggested as a new alternative source of apatite ores. The distinguishing features and minerageny of greenstone complexes in the Karelian, Aldan, and Anabar Shields have been considered. Apatite occurrences have been described in brief. The paper suggests the main lines of study and geological exploration of apatite-bearing metavolcanic sedimentary complexes.     

The Mechanism of Formation of Mesoscale Pulsating Jet Streams in the Earth’s Atmosphere

Izvestiya, Atmospheric and Oceanic Physics - The formation mechanism of local pulsatile jet streams is considered. It may in general be reduced to the following sequence: (i) a breaking gravity...     

Studies of the planetary atmospheres in Russia (2007–2010)

An overview of results obtained in the field of planetary atmosphere studies in Russia in 2007?C2010 prepared by the Commission on Planetary Atmospheres of the National Geophysical Committee for the National Report on Meteorology and Atmospheric Sciences to the XXV General Assembly of the International Union of Geodesy and Geophysics (Melbourne, 28 June?C7 July 2011) [1, 2] is presented.