Analysis of the Northern Hemisphere Atmospheric Circulation Response to Arctic Ice Reduction Based on Simulation Results

The amplified warming of the Arctic is one of several factors influencing atmospheric dynamics. In this work, we consider a series of numerical experiments to identify the role of Arctic sea ice reduction in affecting climate trends in the Northern Hemisphere. With this aim in mind, we use two independent mechanisms of ice reduction. The first is traditionally associated with increasing the concentration of carbon dioxide in the atmosphere from the historic level of 360 ppm to 450 ppm and 600 ppm. This growth increases air temperature and decreases the ice volume. The second mechanism is associated with a reduction in the reflectivity of ice and snow. We assume that comparing the results of these two experiments allows us to judge the direct role of ice reduction. The most prominent consequences of ice reduction, as a result, are the weakening of temperature gradient at the tropopause level in mid-latitudes; the slower zonal wind at 50–60∘ N; intensification of wave activity in Europe, Western America, and Chukotka; and its weakening in the south of Siberia and Kazakhstan. We also consider how climate change may alter regimes such as blocking and stationary Rossby waves. The study used the INM-CM48 climate system model.

Analysis of the Northern Hemisphere Atmospheric Circulation Response to Arctic Ice Reduction Based on Simulation Results

The amplified Arctic warming is one of several factors influencing atmospheric dynamics. In this work, we consider a series of numerical experiments to identify the direct role of the Arctic sea ice reduction process in forming climatic trends in the northern hemisphere. Aimed at this, we used two more or less independent mechanisms of ice reduction. The first is traditionally associated with increasing the concentration of carbon dioxide in the atmosphere from the historic level of 360 ppm to 450 ppm and 600 ppm. This growth increases air temperature and decreases the ice volume. The second mechanism is associated with a reduction in the reflectivity of ice and snow. We assume that comparing the results of these two experiments allows us to judge the direct role of ice reduction. The most prominent consequences of ice reduction, as a result, were the weakening of temperature gradient at the tropopause level in mid-latitudes, the slower zonal wind at 50-60∘N, intensification of wave activity in Europe, Western America, and Chukotka, and its weakening in the south of Siberia and Kazakhstan. We also consider how climate change may alter regimes such as blocking and stationary Rossby waves. The study used the INM-CM48 climate system model .

The Effect of Salinity and Nutrient Load on the Ecosystems of Selected Lakes in the South of Siberia

Salinity largely determines the species diversity and structure of the food web in lake ecosystems. Many studies have been focused on the salinity tolerance of various plankton species. There are fewer studies investigating the modifications in the food web interactions under the effect of salinity. An appropriate system for such studies is closely located lakes of different salinity. We took samples during the summer stratification and analyzed the physicochemical and biological characteristics of 20 lakes (salinity 0.1-35 g/l) in southern Siberia in order to provide general description of this system and to test a number of hypotheses about the effect of salinity on the structure of the food web. The analysis revealed two key factors structuring ecosystems of the studied lakes. The species composition of zooplankton was determined by salinity, with a decrease in the number of species and the transformation of the community from a diverse community of zooplankton (salinity up to 3 g/l) to the dominance of large daphnia (3-8 g/l), copepods (> 8 g/l), small cladocerans and rotifers (20-30 g/l), and Artemia (> 30 g/l). The top predator (fish) was eliminated at salinity above 10 g/l. The biomass of zooplankton did not depend on salinity, but significantly increased in lakes with an increased nutrient load. The nutrient load also had a significant effect on the concentration of total phosphorus, turbidity and transparency of water, and the concentration of chlorophyll “a”. Thus, we recorded the structuring effect of the nutrient load (bottom-up control) on the biomass of the trophic levels and the parameters of water transparency, while salinity transformed the trophic chain from the top, leading to the disappearance of fish and a change in the dominant species of zooplankton. At the same time, salinity did not affect the biomass of the trophic levels. In order to detect top-down effects in the ecosystems of saline lakes, it is necessary to perform a comparative analysis of the seasonal dynamics of ecosystems of lakes with different salinity

VARIATIONS IN THE SURFACE AIR TEMPERATURE IN THE SOUTH OF SIBERIA AND THEIR RELATIONSHIP WITH LARGE-SCALE CIRCULATION PROCESSES IN THE ATMOSPHERE

The article analyzes changes in surface air temperature in the south of Siberia, in 8 regions of the Russian Federation. Based on the geographical and climatic approaches, the study area was divided into four zones. It is shown that interannual changes in air temperature both within the identified zones and between them are consistent, while changes in the series of average monthly air temperatures are not so unambiguous. The calculated values of the linear trends of long-term changes in the mean annual air temperature indicate that, despite its widespread significant increase, in the last decade, a slowdown in the temperature growth has been noted across the territory of southern Siberia. An increase in air temperature is observed in almost all months of the year, with the exception of the winter period, when, according to data from individual meteorological stations, a slight fall in temperature is noted. An assessment of the relationship between air temperature and circulation mechanisms, carried out using correlation analysis, indicates a significant influence of the Scandinavian teleconnection index practically throughout the year in zones related to areas of continental climate. In areas of a sharply continental climate, its influence decreases to some extent, especially in summer, although it remains the leading factor in some months. The ongoing climatic changes cannot but entail both positive and negative socio-economic effects. In this regard, the results of the research should be taken into account when developing mechanisms for adapting the economy to climate change at regional levels.

Research of the ecologo-climatical niche of Brunnera sibirica Stev.

Brunnera sibirica is a Southern-Siberian endemic herb. Being a Pliocene relict, it is included in Red Data Books of many Siberian regions. The aim of our study was to identify the climatic niche and territories suitable for this vulnerable species using the MaxEnt method. The climatic profile of B. sibirica was constructed using the BIOCLIM method with 19 bioclimatic variables. The research has revealed that the climatic conditions in the most of Siberian territory are not suitable for the growth of B. sibirica, which confirms its relic origin in the south of Siberia.

First records of the Dendroxena quadrimaculata (Scopoli, 1771) (Coleoptera, Silphidae) in Tyumen region and possible reasons for its range expansion in Western Siberia

The paper presents data on the first records of Dendroxena quadrimaculata (Scopoli, 1771) in the Tyumen region. D. quadrimaculata is distributed in the European part of Russia, Caucasus and south of Siberia. This species was not previously recorded in the Tyumen region, but within two years (2018–2019), it spread throughout the region. We considered the possible reasons for its range expansion in Western Siberia.

URBAN DEVELOPMENT IN THE SOUTH OF SIBERIA: FORMATION OF COMMUNICATION CORRIDORS

This publication is devoted to the prospects of urban development in the southern part of Siberia, including the Altai territory, the southern part of the Novosibirsk region, the southern tip of the Krasnoyarsk territory, the Kemerovo and Irkutsk regions, the Altai Republic, Khakassia and Tyva. From the North, the territory under study is bounded by the Trans-Siberian railway and from the East by the shore of Lake Baikal. Within the boundaries of the South Siberian settlement system, the author identifies three major settlement systems (agglomeration systems). The first system is developed in the Ob river basins (formed by the confluence of the Biya and Katun rivers) and the Tomi, including the Novosibirsk, Barnaul–Biysk, Kemerovo–Novokuznetsk, and Gorno-Altaisk–Maima agglomerations. The second system is developing along the Yenisei and includes the Krasnoyarsk and Abakan agglomerations and the city of Kyzyl. The third Baikal-Angra system is developing in the triangle Trans-Siberian railway-the West Bank of Baikal – Baikal-Amur highway, including the Irkutsk agglomeration of a number of cities and settlements. Each settlement system has been formed and is developing on the lines of intersection of transport and logical corridors (the Trans-Siberian highway, the Baikal-Amur highway, the Chui tract, and others). The lines of these corridors are determined by natural and landscape factors (coasts of large rivers, mountains, intermountain basins, steppes). The study of typological features of the territory allows to identify directions for the formation of future communication and logistics corridors and the development of a network of interconnected settlements.

Migration in rural areas of Russia: territorial differences

The article analyzes indicators of intensity of migration growth of municipal formations of the rank of district or urban district with completely rural or predominantly rural population. Rural areas in the suburbs of regional capitals and intraregional periphery, as well as those located in the South, the Non-Chernozem region, the South of Siberia and the Far East, the territories of the Far North and its equivalent areas, are considered separately. Both general indicators of the intensity of migration population growth (decline) and by 5-year age groups are compared. The source was data on long-term migration for 2012-2016, published in the Indicators of Municipal Entities databases of Rosstat. The analysis showed that suburban/peripheral differences in the migration balance of rural areas are more pronounced than spatial-geographical (zonal). Age profiles of migratory growth (loss) by geographical zones are similar, but differ in intensity — in the north and east outflow is higher. Suburban and peripheral rural areas in terms of intensity of migration balance differ fundamentally: the most intense migratory growth in all ages except for the youngest is noted in the suburbs.

The carbon isotopes ratio in small lakes bottom sediments located in the forest-steppe and steppe zones of southern Siberia

Isotopic variations of carbon of the carbonates and organic matter in bottom sediments of lakes of two lake systems located in the South of Siberia are studied: Baraba (Baraba steppes) and Tazheran (Tazheran steppes). Isotopic studies of δ13C carbonates and organic matter of the lacustrine bottom sediments of the Tazheran and Baraba systems indicate two main mechanisms of authigenic carbonates formation: chemogenic deposition and biochemogenic deposition due to bacterial destruction of organic matter. The dependence of the δ13Corg and δ13Ccarb, the degree of water salinity is not revealed. Forms by chemogenic carbonates are similar to water isotopic values, i.e. with dissolved bicarbonate - ion reservoir. However, in most of the studied lakes the light isotopic composition δ13Ccarb was revealed, as carbonates are formed in the environment with a high content of isotope-light CO2 formed by the oxidation of carbon dioxide emitted by bacteria-decomposers in the mineralization process of the original organic matter in the stagnant waters in the anaerobic environment.