Home – Home – Jornals – Advanced Search

Atmospheric waves on a planetary scale play the main role in the formation of the atmosphere regime, and a polar vortex forms in the stratosphere in winter. A striking example of the interannual variability of the stratospheric polar vortex caused by stationary planetary waves is sudden stratospheric warming (SSW). The internal dynamics of major sudden stratospheric warming accompanied by displacement and splitting of the stratospheric polar vortex (SPV) was studied based on the MERRA-2 reanalysis data from the point of view of explicitly calculating nonlinear interactions of planetary waves with each other and with the mean flow to identify similar trends in the formation of SSW of various types. In particular, it is shown that the formation of a SSW with SPV splitting is not always accompanied by dominant variations in the wave activity of stationary planetary wave with zonal wavenumber 2 (SPW2), but is determined by the maximum interactions of SPW2 with the mean flow. It was obtained that the wave-wave interactions during the generation of secondary stationary planetary wave with zonal wavenumber 1 (SPW1) are maximal 1-2 weeks before, and during the generation of secondary SPW2, 5-10 days before a SSW with SPV displacement. The results aimed at identifying predictors of SSW formation are important due to the fact that SSW significantly affects the entire middle atmosphere, ionosphere, as well as weather conditions in the troposphere and the formation of extreme weather events.

Solar thermal tides have a significant impact on global atmospheric circulation, making it important to study the various external factors that can influence their generation and propagation throughout the atmosphere. Using the mechanistic nonlinear numerical general circulation model of the middle and upper atmosphere (MUAM), this paper examines the influence of solar activity (SA) variations on the spatiotemporal structure of tides. Two ensembles of MUAM simulations of the global atmospheric circulation in January are considered, each consisting of 16 runs, corresponding to high and low SA. It is shown that with increasing solar forcing at high SA, the diurnal migrating tide (DW1) weakens in the altitude range 100-150 km and intensifies at higher altitudes. The analysis of the Eliassen-Palm (EP) fluxes demonstrates a significant correlation between changes in the vertical propagation of wave activity and the amplitude of DW1: downward flux increments generally correspond to tide weakening in the range 110-150 km, while upward flux increments correspond to strengthening of the tide above 150 km. The semidiurnal migrating tide (SW2) weakens at high SA at altitudes of up to 140 km in the Southern Hemisphere and 190 km in the Northern Hemisphere in the mid- and high-latitude thermosphere. This is accompanied by mainly weakening of the ascending EP fluxes. Above 200 km, SW2 amplitude in the Northern Hemisphere increases by a factor of 2-3 at high SA. Above 150 km in the thermosphere, the amplitude of the stationary planetary wave with zonal number 1 (SPW1) decreases at high SA, while the amplitude of the migrating tides increases. Taken together, this leads to a complex structure of changes in the amplitudes of non-migrating tides. As an important link in the dynamic relationship between atmospheric layers, tides, in particular, provide the distribution of the effect of changing solar forcing during varying solar activity across all atmospheric layers. Understanding the complex mechanisms of dynamic interactions between tides and atmospheric circulation is important for improving numerical forecasts of changes in atmospheric processes on various time scales, from days to decades.

A detailed study of the spatial distribution of aerosol sources is essential for understanding their impact on air quality and public health. The source fields of various atmospheric aerosol types arriving to the Middle Urals were estimated with the use of the analysis of the potential source contribution function. The initial data comprised information on the aerosol type obtained through the classification of aerosol particles based on the spectral values of atmospheric aerosol optical depth. The results demonstrate a clear spatial differentiation of atmospheric aerosol sources for the classes “dust” and “elevated smoke”. The proposed approach can significantly enhance the information provided by spectral ground-based photometric measurements, thus improving the accuracy of air quality assessments.

The peculiarities of reproduction and population structure of the northern red-backed vole in the northern taiga of Western Siberia are considered. Rodent trapping was carried out in the snowless period using the method of ditch with pitfalls (guide fences made of polyethylene film) and trap-lines. A total of 2704 northern red-backed vole were recorded in the southern strip of northern taiga over a 9-year period and in the northern strip of northern taiga over a 4-year period. The reproductive participation of females was determined by the presence of embryos and placental scars, the participation of males by the presence of spermatozoa in the epididymis and the size of the testis. The age of voles was determined by M² root development, and mass, body length, and thymus development were used. Adult overwintered voles have a reproductive period of up to five months, and up to three months for young voles. Overwintered males remain sexually active throughout the entire snowless period. Overwintered females of the southern strip bring three litters, and young females two litters. Most overwintered females in the northern strip bring two litters, and in rare cases a third litter is possible, while young females bring two litters. In the southern strip in April-May, and in the northern strip in June, the northern red-backed vole population is represented exclusively by overwintered animals. In August and September are universally dominated by young. Males predominate among adults and young animals, only in late summer and autumn the numerical advantage is shifted towards females among overwintered animals.

The plague microbe (Yersinia pestis) is unique in the family of pathogens of intestinal infections of the family Yersiniaceae (Enterobacteriaceae) and the genus Yersinia. This is the only species of the family and genus that, in natural conditions, is transmitted in rodent populations not by an alimentary route, as typical intestinal pathogens, but by a transmissible way through flea bites, which indicates some unique circumstances of its speciation. Such a special circumstance was the wound infection in populations of the Mongolian marmot (Marmota sibirica) with the causative agent of pseudotuberculosis of the 1st serotype (Y. pseudotuberculosis O:1b) or, in other words, Far Eastern scarlet-like fever (FESLF). The abiotic trigger for speciation was the maximum Sartan cooling, which covered vast areas of Central Asia at the turn of the Pleistocene and Holocene, 22-15 thousand years ago. Deep freezing of the ground in the settlements of the Mongolian marmot led to a change in the behavior of the larvae of the marmot flea Oropsylla silantiewi - a transition to hematophagy on marmots during hibernation, which caused a massive penetration of the FESLF pathogen into the blood of marmots through wounds on the mucous membrane in the oral cavity, created by flea larvae. Aberrant resistant wound infection of marmots with FESLF caused change in gene flow and speciation of Y. pestis. According to the optimistic version of the environmental scenario, the speciation process took place autonomously in three geographical populations of marmots; almost simultaneously, three initial microbial subspecies 2.ANT3, 3.ANT2 and 4.ANT1 appeared, which later became the basis of the entire world intraspecific diversity of this pathogen.

The results of parasitologic and metagenomic study of two nests of the long-tailed gopher obtained in the Tuva mountain plague focus (Mongun-Taiga kozhun of the Tyva Republic) are presented. The fauna of blood-sucking arthropods of both nests was formed by fleas Citellophilus tesquorum Wagn., Frontopsylla elatoides Wagn., Rhadinopsylla li transbaikalica Ioff et Tifl., Oropsylla alaskensis Baker, Neopsylla mana Wagn. and ticks Haemogamasus mandschuricus Vitzthum and Hg. hodosi Goncharova et Buyakova. F. hetera Wagn., F. frontalis baikal Ioff were sporadically present in nest No. 1. According to the size, depth of occurrence, length of passage to the nest chamber, species composition and physiological state of ectoparasites, nests were defined as wintering nest No. 1 and reserve nest No. 2. According to the results of metagenomic analysis, nest community No. 1 contained 64.2 % of Proteobacteria phyla (Allorhizobium - 22.8 %, Aureimonas - 9.71 % and Methylobacterium - 7.68 %), 35 % of Actinobacteria (including Brachybacterium - 3.8 %, Amycolatopsis - 3.33 %, Brevibacterium - 1.76 %), 0.8 % of Firmicutes (Staphylococcus). In the sample from nest No. 2, 87.1 % of sequenced sequences belonged to Actinobacteria phyla (Brachybacterium - 51.0 %, Brevibacterium - 19.6 % and Nocardioides - 7.4 %), 12.8 % to Firmicutes (Staphylococcus), 0.08 % to Proteobacteria (Methylobacterium). Possible reasons for the differences in the composition of nest bacterial communities are discussed.

Extreme weather events change the diurnal and seasonal variations in CO₂ fluxes between the forest and the above surface atmosphere. The analysis of interannual variability of net CO₂ exchange (NEE), total ecosystem respiration (TER), gross ecosystem photosynthesis (GEP) and evapotranspiration (ET) in a cowberry-lichen pine forest of the middle taiga subzone was performed under different weather conditions during the 2021-2023 growing season. According to measurements by eddy covariance system, in the pine forest over three years of observations, the total NEE in May-August varied from -653 to -980 g CO₂/m², GEP varied from 1711 to 2360 g CO₂/m², TER - from 913 to 1380 g CO₂/m². The total evapotranspiration corresponded to 137-262 mm, and the GEP/ET ratio varied within 1.8-3.9 mgC/g H₂O. As a result of multi-level statistical analysis, a correlation GEP with gross radiation, temperature and humidity in the growing season was revealed. A relationship between GEP and air temperature and humidity characteristics of the growing season was revealed. GEP and NEE decreased at abnormally high temperatures and a long absence of precipitation in the first half of the 2021 growing season. Maximal effect of air temperature on ecosystem CO₂ exchange was observed in 2023 at increased supply of soil moisture. It was concluded that the water reserve in the soil mitigates the negative effect of atmospheric moisture deficit in the summer on photosynthesis and evapotranspiration and thereby ensures a stable seasonal net sink of CO₂ in the ecosystem of the cowberry-lichen pine forest of the middle taiga subzone.

Understanding the relationship between the conditions prevailing in anthropogenic altered soils and the diversity of the soil microbiome can provide important information for assessing the state and solving the problem of maintaining the stability of natural and man-made ecosystems. Using high-throughput Illumina sequencing, the diversity and composition of bacteria, archaea, and fungi in the soils of five different phytocenoses within the Meshcherskaya Lowland (Southern Moscow region), as one of the most industrially saturated regions in the country, were analyzed. The results showed a reduction in taxonomic richness and a decrease in phylogenetic diversity and alignment of microbial communities during the transition from the soil of a conventionally background site to soils of secondary phytocenoses and soils associated with man-made objects - an overgrown phosphogypsum dump and an industrial wastewater discharge site. Representatives of 28 bacterial and 1 archaeal phylum were identified in the prokaryotic component of the microbiomes of the studied soils. The dominant position was occupied by the phylum Actinomycetota (relative abundance 21-30 %) and Pseudomonadota (16-19 %). The taxonomic composition of the fungal component of the communities was dominated by Ascomycota (53-74 %), represented by the classes Dothideomycetes, Sordariomycetes, Eurotiomycetes, and Leotiomycetes. Representatives of Basidiomycota in the soils of different phytocenoses accounted for from 16 to 29 % of all identified fungal taxa. The most numerous among the basidiomycetes were the classes Tremellomycetes, Agaricomycetes, and Microbotryomycetes. Using the FAPROTAX software package for predicting the ecological functions of bacterial and archaeal taxa obtained by sequencing 16S rRNA amplicons, as well as the automatic FUNGuild algorithm for sorting by ecologically significant categories of the fungal taxa identified during ITS amplicon sequencing, the ecological profiles of the studied microbial communities were characterized. The data obtained can be used in the environmental monitoring system of impact zones of industrial enterprises.

Biosorption is a promising method for preventing REE migration in natural environments and for their purification, and microscopic fungi are considered effective biosorbents. The article is devoted to studying the biosorption capacity of soil microscopic fungi in relation to REE in aqueous solutions. The dyna`mics of adsorption was studied using the example of lanthanum by the biomass of micromycetes Penicillium canescens and Talaromyces funiculosus depending on the contact time and its concentration in the solution. It was found that adsorption equilibrium in the fungal biomass - aqueous lanthanum solution system occurs within 24 hours, the T. funiculosus biomass demonstrated a higher sorption capacity. Lanthanum adsorption is more intense at medium acidic pH values of solutions; the maximum lanthanum sorption for 24 hours was noted at pH 3.1 by P. canescens biomass. It was revealed that REE with larger ionic radii are extracted more effectively, they more actively occupy free sorption centers with the formation of complexes. With prolonged interaction of REE with fungal biomass, nanoparticles are formed, the composition of which is close to monazite. According to IR spectroscopy data, the REE sorption centers are amide, carboxyl, amine and phosphate groups of the fungal cell wall. The presence of many ionogenic groups determines the high sorption capacity of the fungal cell wall. Intermolecular modeling of the interaction of lanthanum with amino acid residues of fungal cell wall proteins revealed that proteins form strong complexes by complex formation of REE with amino acid residues, where the active centers are glutamic and aspartic amino acids.

Based on the results of microbial indication for 2023 and 2024, it was established that Avacha Gulf and the southwestern coast of Kamchatka are subject to significant oil pollution. The number of hydrocarbon-oxidizing microorganisms at most of the studied stations was 10³ CFU/ml (g) and higher. The results of molecular genetic analysis identifying marker bacterial genes for the oxidation of alkanes (ALK-1, ALK-2, ALK-3) and PAHs (nah, phn, bphA1, xylE, GN-PAH, GP-PAH) in the environment indicated the dominance of bacteria capable to oxidize short- and medium-chain alkanes in the surface waters of Avacha Gulf in 2023, and bacteria that are potential destructors of medium- and long-chain alkanes in the waters of the southwestern coast of Kamchatka. Also, the waters of both areas were characterized by a significant presence of gram-negative bacteria that oxidize various types of PAHs. In 2024, the proportion of stations with bacteria that degrade phenanthrene and short-chain alkanes sharply decreased in Avacha Gulf, but the proportion of stations with microorganisms that oxidize long-chain alkanes increased. An increase in the proportion of water samples with bacterial biphenyl oxidation genes and PAH oxidation genes of gram-negative microbiota was noted for the southwestern coast of Kamchatka. In bottom sediment samples collected in 2023 from both study areas, the genes responsible for PAH oxidation by gram-positive microbiota and for the degradation of long-chain alkanes were most often detected. Analysis of bottom sediment samples collected in 2024 indicated a decrease in the proportion of stations with microorganisms capable of oxidizing various petroleum hydrocarbons in both study areas.