CONDITION OF FIELD PROTECTIVE STRIPS IN CONDITIONS OF STEPPE ZONE OF VORONEZH REGION

The paper presents the results of studies of protective strips located in the Voronezh region in the Rossoshansky district. The characteristic of biometric data of forest belts of the same age and their dependence on the density of planting, width of strips and row spacing is given. The comparison of the soil, its impact on the growth and development of trees is displayed. The influence of the design of protective forest stands on the temperature of the surface air layer is also shown. The state of the plantings and the factors that adversely affect it are determined: the lack of care measures, deforestation, clutter and the presence of a large number of diseases and pests.

Detecting the relations between meteorological elements and alpha and beta activity concentration at Al-Tuwaitha site, Baghdad

In this study, 50 samples of air particulates collected from different places in- and outside the Al-Tuwaitha nuclear site, south of Baghdad were used to measure daily gross alpha and beta activity concentrations (AAC and BAC) for the period from 28 January 2015 to 13 April 2017. At the same time, several meteorological factors such as air temperature, wind speed, wind direction, air pressure, relative humidity, and solar radiation, were also measured. Air stability classes were also derived from wind speed and solar radiation. AAC/BAC variations in the surface air layer were discussed in relation to these factors. The results show that there are inverse relations between AAC/BAC and wind speed and temperature, linear relations between AAC/ABC and air pressure and weak relations between AAC/BAC and relative humidity and solar radiation. Lastly, AAC/BAC measurements in unstable air are as large as in neutral air.

ON THE THERMAL REGIME OF THE SURFACE AIR LAYER IN THE DEBED RIVER BASIN (ARMENIA)

The features of the thermal regime of the surface air layer in the Debed river basin are considered. A statistical analysis of the average annual and average seasonal values of air temperature from 1964 to 2018 was carried out, two periods were identified, their time course was shown. The analysis was carried out using data from six meteorological stations representing the lowland, mountain and high-mountain climatic zones of the Debed river basin. A correlation was obtained between the absolute altitude and the monthly average values of air temperature for January and July, which can be used to assess the thermal conditions of unexplored or poorly studied territories and for cartography. The time course of average values of air temperatures for the seasonal period has been studied. Analysis of trend lines of temporal changes in air temperatures shows that in all situations on the territory of the basin as a whole, there is a tendency of temperature growth. Moreover, with a range of interannual fluctuations, a break in the course of temperatures in the early to mid 1990 is clearly visible, after which their significant increase began. It turned out that a significant increase in seasonal temperatures is observed especially over the period 1993-2018, which means that the annual warming after the mid 1990 occurred primarily due to summer and spring seasons. The regular dynamics indicates that in the studied area in terms of temperatures, a tendency of softening winters, a decrease in the water content of rivers, aridization of the climate. The results obtained can be used to assess the regularities of the spatial-temporal distribution of the temperature of the study area, to clarify the thermal balance, for the rational use of heat resources, as well as in the development of strategic programs for longterm analysis.

Radioactive Aerosols within Conditions of the New Safe Confinement in 2017–2020

The results of monitored behavior of radioactive aerosols within the conditions of the New Safe Confinement (NSC) in 2017–2020 are presented. Maximum “unorganized” flux of beta-emitting products of the Chornobyl accident from the Shelter object through the process openings and leakages of light roofing in the NSC basic volume observed in 2017 made 7.9 kBq/(m2 ∙day). Mean annual density of radionuclide deposition onto the light roofing during four years has been changing within the range of 1.7–2.2 kBq/(m2 ∙day). Over these years, mean annual volumetric activity of sum of long-lived beta-emitting nuclides coming in the “Bypass” system dropped from 0.84 to 0.17 Bq/m3 . Their carriers were aerosol particles with activity median aerodynamic diameter, mainly, from 4.3 to 10 μm. The data are given on radioactive contamination of near-surface air layer in the NSC basic volume.

VARIABILITY OF WINTER EXTREME LOW TEMPERATURES OF THE SURFACE AIR LAYER IN THE LAKE SEVAN BASIN (ARMENIA)

The purpose of this work to study, analyze and evaluate the patterns of spatial variability of long-term fluctuations in winter extreme low temperatures of the surface layer of atmospheric air in mountainous territories of Armenia (for example, the lake Sevan basin). To achieve this goal, the results of actual observations by Armhydromet and the available literary sources have been collected, processed and analyzed. As a result of the analysis of the values of extreme low temperatures, it can be noted that the genesis of winter extreme low temperatures is different in the territories under consideration. Winter extreme low temperatures stand out for their uneven distribution – they range from -26.3 to -38.1. For the calculation of winter extreme low air temperatures of unexplored or poorly studied territories, correlations were obtained between the value of extreme low temperatures and the altitude of the area above sea level. In the study area, a tendency towards an increase in winter extreme low temperatures is mainly observed. The scientific novelty of the obtained results lies in the fact that in modern observational materials, for the first time, the regularities of the variability of the spatio-temporal distribution of winter extreme low temperatures of the surface air layer in the lake Sevan basin are estimated. Findings • The study of the patterns of variability of the spatial-temporal distribution of winter extreme low temperatures of the surface air layer under conditions of regional and global climate change is an urgent task of modern geographical science; • Winter extreme low air temperatures are mainly due to the nature of the underlying surface and the features of the relief. The smallest values are observed not in high-altitude zones, but in those places where cold air accumulates (that is, in depressions). In winter, in the hollow valleys, an inversion is mainly observed- in parallel with the height, the air temperature rises. In valleys, as a result of the accumulation of cold air, low temperature conditions can be observed for quite a long time; • The study area is distinguished by a characteristic regime and an uneven spatial distribution of winter extreme low temperatures. They range from -26.3 (Semenovka) to -38.1(Masrik). • Winter extreme low temperatures rise up to 2000-2100m with altitude, and on the contrary, they decrease at altitudes above 2000-2100m. The vertical temperature gradient is -0.5C/100m and 0.8C/100m, respectively; • On the basis of the obtained correlation between winter extreme low temperatures and terrain heights, two regions were identified: 1) heights up to 2000-2100m and 2) 2000- 2100m and higher; • Temporal trends during perennial winter extreme low temperatures are mixed. In the study area, these is a predominance of positive trends. Negative trends are characteristic for the period 1935-1966 at the Sevan, Masrik and Martuni meteorological stations; • In the study area, winter conditions become thermally milder, which should be taken into account when developing strategic programs for the future development of this area.