Physics of the Atmosphere, Climatology and Environmental Monitoring

The article provides brief information on the history of the development of hail suppression works in the USSR and the Russian Federation, the main provisions of the currently used Russian automated rocket technology to prevent hail, the characteristics of a modern anti-hail protection system, including the radar parameters of seeding objects (hailstorms), the average annual number of seeding objects, the consumption of rockets and glaciogenic agents for seeding objects of different hail categories, the results of assessing the physical effectiveness of long-term protection against hail, the main problems and prospects for further improvement of rocket technology.

Lightning is a powerful electrical discharge in the atmosphere, which occurs due to the potential difference inside a thundercloud or between a cloud and the ground. To prevent the detrimental effects of lightning, lightning protection measures are organized. The effectiveness of them largely depends on a well-executed grounding system. In the above work, an experimental and theoretical study of the physical and statistical characteristics of thunderstorm activity and the susceptibility of the territory and objects to lightning, characteristic of the territory of the North Caucasus, was carried out. A map of the average annual lightning strike rate of the territory of the North Caucasus has been constructed.

The article considers the influence of the daily rotation of the Earth on the oscillatory processes in the atmosphere. When considering axial rotation, diurnal changes in air temperature are taken into account. If the frequency of Brent-Väisälä coincides with the frequency of the daily rotation of the Earth or their difference is insignificant, then phenomena such as resonance or beats occur. In a standard atmosphere, the Brunt—Väisälä frequency is many times greater than the axial rotation frequency, so these cases are very rare. However, such high-intensity fluctuations can lead to significant periodic temperature changes at the considered point.

The analysis of changes in meteorological parameters according to the data of two high-altitude weather stations of the Central Caucasus “Klukhorsky Pass” 1960–2020 and “Shatdzhatmaz” 1950–2020 was carried out. The weather stations are located at an altitude of about 2000 m. It has been established that in recent decades, the thermal regime of the high-altitude zone of the Central Caucasus is characterized by an increase in air temperature, which is most noticeable in recent decades and is 1.4° at the Klukhorsky Pass weather station and 2.2° at the Shatdzhatmaz weather station. Humidity data from the Klukhorsky Pass weather station show a long-term variation lasting about 35 years with highs near 1985 and 2010. Perhaps this is due to the Brückner cycle.

The work is devoted to the problems of reducing risks in tourist and recreational areas of mountainous areas associated with climate change. The main factors through which this global factor can influence this area of activity are discussed. Such slope processes as snow avalanches and mudflows are considered as such factors in mountainous areas. It is noted that the reduction of risks in the tourist and recreational zones of mountainous areas associated with climate change requires adaptation of the functioning of these zones to climate change. In this case, it is considered appropriate to consider this problem for two cases. In the first case, this problem is considered for a functioning tourist and recreational zone, and in the second case, for the zones being created, taking into account the consequences of climate change. The formulations of the tasks of adapting the existing tourist and recreational zones of mountainous regions to climate change are given, the features of information support and methods for solving these problems are discussed. A method for solving one of these problems is presented, namely, the development of models for reducing risks in the tourist and recreational zone associated with such a climatic factor as snow avalanches. It is noted that the features of the information support of this problem, which consist in the presence of uncertainties, make it natural to search for a solution to this problem within the framework of decision theory. The statement of this problem is given.

The reasons for the slowdown in the development of the convective cloud physics and active influences on them in recent decades are discussed. As the results of the analysis showed are that the present period of time is a transitional one for this scientific direction: there is a transition from the stage of studying “elementary” processes in clouds to the stage of studying the formation and development of clouds as a whole, considering their systemic properties. The main tasks arising at the coming stage of its development are formulated. It is noted that such tasks include aggregating the results of studying “elementary” processes in clouds and studying the role of systemic properties of clouds in the formation of macro- and microstructural characteristics of clouds. The state of research on the development of numerical models of convective clouds, within which the aggregation of “elementary” processes in clouds is carried out, is touched upon. As for the study of the role of the system properties of clouds in the formation of their macro- and microstructural characteristics, the study of the role of the interaction of clouds with the atmosphere surrounding them (the property of the hierarchy of systems) and the interaction of processes in clouds, which are the most important structure-forming factors for clouds, seems to be the most important and difficult task in this area of research. Methods and some results of research in this direction are presented, which confirm the significant role of these factors in the formation and development of clouds, in the formation of their macro- and microstructural characteristics.

The purpose of the work is to analyze the problem of adaptation of various fields of activity to climate change, to formulate the tasks of adapting the agro-industrial complex (AIC) and to analyze the features of information support and methods for solving the tasks of its adaptation plan, to develop a method for solving one of the tasks of this plan the formation and coordination of target indicators of the development of the agro-industrial complex. To solve the above problems, the results of the analysis of climate change in the territory of the North Caucasus, the model for optimizing the functioning of the “crop industry—processing industry” system, developed to form and agree on target indicators for the development of the regional agro-industrial complex, were used. It is noted that at the regional level it is not advisable to limit adaptation to climate change only to agriculture, this problem at this level should be considered for the “agriculture—processing industry” system, taking into account the relationship between its elements, the goals of adapting this system to climate change are formulated. The formulations of the tasks of the adaptation plan for the regional agro-industrial complex are given, the approach to solving the problem of forming and coordinating the target indicators of the agro-industrial complex is outlined, some calculation results are given. The main results of the work are: the formulation of the tasks of adapting the agro-industrial complex to climate change, the model for optimizing the functioning of the “crop industry—processing industry” system, developed to solve the problem of forming and coordinating target indicators for the development of the regional agro-industrial complex.

Object: to analyze the mechanisms of the impact of climate change on demographic processes and to determine methods for reducing their consequences for the demographic state of society. Methods: review of literature data on the results of analysis and forecast of climate change, as well as its consequences for human health. Also, analysis of the influence of other global factors on the demographic state of society. Results: the analysis of the problem of adaptation to climate change of demographic processes was carried out. Conclusions: under the influence of climatic factors, powerful migration flows from the islands and coastal zones of the oceans will be formed. Due to the rise in the level of the world ocean and the increase in the power of hurricanes, the likelihood of the disappearance of island nations in the oceans will increase significantly. Also, under the influence of these phenomena, there will be an expansion of the area of the coastal zone along the oceans with unfavorable living conditions. With the frequent and intense impact of these factors, the flows that will be directed to neighboring countries that are less affected by these factors.

The problem of climate change is currently attracting the attention of specialists in various scientific branches. The great interest is the analysis of the consequences of climate change on the development of various sectors of the economy. For balneology, this problem is also relevant, since the climate is often one of the important therapeutic factors in resort regions. Pyatigorsk, along with other cities of the ecological resort region Caucasian Mineralnye Vody, is famous not only for its mineral water sources, but also for its healing climate. However, systematized data on the climate of Pyatigorsk are contained only in issues of the Handbook on the Climate of the USSR and refer to the observation period up to 1966. Due to the climate changes taking place on the planet, these data, of course, are outdated. This article is devoted to the study of the current climate and the temporal dynamics of changes in the main climatic characteristics of the Pyatigorsk resort. The article describes modern climate and the temporal dynamics of the change of major climatic characteristics of Pyatigorsk resort. Data on the temperature regime, precipitation regime, snow cover, wind, as well as data on the frequency of adverse and dangerous weather phenomena are analyzed.

Today neural networks (NN) are omnipresent and its using is continuously growing in different areas like automation and optimization, researching, health care, engineering etc. This is due to NN possibility to recognize difficult patterns and structures. There are feed-forward and recurrent neural networks (RNN) among various architectures. Former implies only one-directional neuron’s relations, later permits bidirectional neuron’s interactions which mean possible cycles occurring, similar with cyclic graph. Nowadays RNN are within the best NN architectures for time series predictions. This paper we applied one of RNN architectures, namely long short-term memory (LSTM) for surface temperature time series prediction purposes, producing only short-term forecasts, not more than three hours lead time. Data was sourced from automatic weather station (AWS) archive, located in the Saint-Petersburg. The results obtained from conducted experiments showed LSTM fairly good performance. We also induced an algorithm to train LSTM and tackle with required predictions deadlines.

Climate change over the past two decades, driven by a variety of factors, including greenhouse gas emissions, is unprecedented. As the temperature rises, the absolute humidity increases, reaching a maximum in July–August. Based on the close relationship between the values of the average annual temperature and absolute humidity, one can assume that water vapor is the main factor responsible for changing the temperature of the surface air layer.

The difference in the level and relative temporal variations of input signals of multifrequency microwave radiometric system sets certain requirements to the task of increasing its sensitivity. In general, for low-frequency channels, increase of sensitivity is caused by the requirement of accuracy and reliability of assessment of possible small increments of input signal, and for high frequency measurements perfect identification of the temporal trend of the signal level, especially during studies of fast flowing atmospheric processes. This article is devoted to research of influence of change of sensitivity of multifrequency microwave radiometric system at variation of one of radiometer parameters—time constant of accumulation of an output signal on accuracy of measurements at changing meteorological conditions.

“Invisible” mountain waves are a particularly dangerous type of atmospheric disturbances associated with a high risk of aircraft operation in conditions of orographic turbulence. The paper presents the experience of using a digital Gabor filter to improve the quality of detection of “invisible” orographic waves in satellite images in water vapor channels. In the course of the work, an archive of 20 MODIS/Aqua, Terra multispectral images with “invisible” orographic waves for 2000–2020 was formed. The results of numerical experiments demonstrate the successful extraction of mountain waves in satellite images using the Gabor filter. The Gabor filter is resistant to scaling, rotation, brightness and contrast changes.

The nonlinear problem of the acceleration of heavy particle picked up by a fast flow in a gravity field is studied analytically. This problem is interesting, in particular, in connection with dangerous convective phenomena in the lower atmosphere (heavy wind gusts, tornadoes). Heavy particles/objects carried by intense winds are one of the main hazards associated with such phenomena. The corresponding theoretical problems are complicated by the nonlinear dependence of the hydrodynamic resistance on the velocity of the particle relative to the medium, and were studied, as a rule, by numerical methods. The paper considers an analytical model that makes it possible to establish some general regularities of particle acceleration in the non-stationary flows. According to the solutions derived, the characteristic time of the acceleration of a particle during a fast intensification of the flow is an order of magnitude of the ratio of the particle settling velocity in the gravity field to the acceleration of gravity.

Errors of radar measurement of precipitation are investigated at the High-Altitude Geophysical Institute with the help of a locator and a network of pluviographs. It is shown that the radar, subject to its correction by ground data, is a very reliable and accurate measuring device. The radar method of measuring precipitation has an advantage over ground measurements, it covers a large area (within a radius of 128 km), efficiency (in real time). Studies have shown that the radar, provided it is calibrated with ground data, is a very reliable and accurate measuring device. The conducted comparisons of radar and ground measurements of precipitation showed that almost always the matching coefficient is greater than one and on average for seven years it varied from 1.3 to 1.5. This suggests that the radar systematically underestimates the size of the thickness of the precipitation layer by 1.3–1.5 times. The average relative error of measuring total precipitation for the summer season by radar method does not exceed 42%.

It is well known that the radar reflectivity of the precipitation zone Z is related to the intensity of precipitation I. The heavier the precipitation, the higher its reflectivity. The presence of such a relationship makes it possible to determine both the very fact of the presence of precipitation and its intensity from the measured Z values. By measuring the intensity of precipitation at different points in time, it is possible to calculate the amount of precipitation. The error of radar measurement of precipitation amounts can be easily determined by comparing radar readings with data from ground-based precipitation gauges. In this case, the data of the precipitation gauge are taken as “true” and are, as it were, reference. Recently, a large amount of work has been done to compare the intensities and amounts of precipitation measured by contact (precipitation network) and remote (radar) methods. It was found that along with good matches, there were significant differences in precipitation parameters. This is due to the large heterogeneity of precipitation and the previously unknown parameters of the Z–I ratio. Therefore, radar data is usually corrected by ground data. To reduce errors in radar measurements of precipitation, such measurements are made as close as possible to the Earth's surface, at a level of 0.5–1.0 km. However, in conditions of rough terrain in the mountains and foothills, this condition often cannot be met.

The currently existing radar methods for determining the microphysical characteristics of hail require constant improvement. The purpose of this work is to consider radar methods for determining the hail microstructure (two-wave and single-wave methods). The result of long-term studies of the microstructural characteristics of hail growing in a cloud is presented. A comparison is made of the results of determining the hail size by the two considered methods. The repeatability of some parameters of real hail spectra is determined. More than 600 hail clouds of various intensities that developed over the territory of the KBR and adjacent areas were studied. Based on the results of many years of research, a curve was constructed that describes the correlation between concentrations and the average cubic hail diameter in the growth zone at the moment of maximum development of convective cells.

The article describes ground-based measurements of precipitation by a network of ground-based precipitation gauges. The main task is to restore the precipitation field from the values measured at reference points (location of precipitation gauges). Precipitation fields were measured using a network of automatic weather stations Vantage Pro2 created at the High Mountain Geophysical Institute. For remote measurement and construction of precipitation fields for various local areas of the territory of the Kabardino-Balkarian Republic (KBR) and adjacent areas, data from a meteorological radar located at the research site of the High-Mountain Geophysical Institute “Kyzburun” are used. The data from it were sent to the FTP server of the High Mountain Geophysical Institute, from where they were further used upon request to construct sediment fields. Similar studies of the precipitation regime were carried out for the catchment area of the Nalchik River. When carrying out radar measurements of precipitation, the entire length of the Nalchik River was conditionally divided into three approximately equal sections: the upper, middle and lower reaches. In this case, the catchment was divided into squares 2 × 2 km. The conducted studies of precipitation fields for the territory of Nalchik and surrounding villages in June 2012 showed that the average precipitation layer is 31.2% less than that obtained according to the data of the Kabardino-Balkarian Center for Hydrometeorology and Environmental Monitoring. The method of constructing precipitation fields can be used to predict nano-water floods of storm origin and monitor mudflow hazard.

Thunderstorms affect aviation operations. Weather forecasters providing aviation forecasts need to develop the accuracy of forecasting. In addition, according to some studies, thunderstorms are becoming more frequent due to climate change. It has been analyzed those synoptic conditions with thunderstorms occurred at different times of the year. The indices of convective instability of the air mass, successfully predicting the presence and absence of thunderstorms, were considered and systematized.

The need to develop new methods for predicting the characteristics of hail processes is dictated, on the one hand, by the trend of growth of convective dangerous weather events due to climate change, on the other hand, by the lack of actual data of aerological sounding due to the location of individual weather stations far enough from each other and the existence of a significant time interval of measurements. In this research instead of upper-air atmospheric sounding data, it is proposed to use the output of the GFS NCEP global atmospheric model, which has sufficient accuracy and the required lead time. The size of the hail is considered as a quantitative characteristic of the hail process. The hail assessment regression model was implemented using statistical analysis methods based on pre-calculated atmospheric parameters that are most responsible for the development of convective phenomena. The model parameters characterizing the statistical significance and practical applicability of the model showed the possibility of applying the proposed model in practice.

The paper presents the results of the study of the regime of snow cover and snowstorm phenomena in the Stavropol Upland in the first twenty years of the twenty-first century. It is shown that against the background of increasing winter temperatures, the timing of snow cover appearance shifts to later dates, and periods of continuous snow cover for 30 days or more are observed only in 30% of years. In addition, on the Stavropol Upland there is a decrease in the number of days with snow cover, a decrease in the frequency of years with stable snow cover, and an increase in the frequency of snowless months of the cold period, especially November and December. Also, comparison of the current characteristics of the snowstorm regime with the data for the previous multi-year periods showed that the frequency and duration of snowstorms in the Stavropol Upland decreased, despite an increase in the number of days with strong winds. The main reason for the changes occurring is primarily an increase of air temperature in winter and transitional periods of the year.

At present, among the many tasks in the field of active influences on clouds, one should single out issues related to the study of reagents and means of influencing clouds. Under laboratory conditions, the crystalline properties of many substances are studied (the pyrotechnic composition of an As rocket with the addition of aerosol particles of a smoke bomb, the pyrotechnic composition with AgI with the addition of graphite, ZnO nanotubes). At the same time, fundamental laboratory experiments are being carried out to study the effect of electricity on the formation of an ice phase on the particles of the reagent and zinc oxide. At present, it is already known that the presence of an electric field in clouds and a charge on reagent particles can affect the specific yield of ice-forming nuclei when working on active influences on cloud processes. Moreover, nanosized particles, as well as particles of reagents, depending on the shape, can increase the electric field near their surface by thousands of times, which can lead to a significant increase in the temperature threshold for the formation of an ice phase on reagent particles.

An approximation of the refractive index vertical profile in the troposphere of St. Petersburg and Moscow has been performed. The coefficients of the exponential regression equation at different times of the day and in different seasons of the year are determined: the value of the refractive index in the surface layer and the exponent responsible for the rate of change of the index with height. The refractive index gradient at the stations under consideration varies within –33 ÷ –46 N-units/km, which corresponds to substandard and superstandard refraction types.

The article investigates the role of the cloud system properties based on a comparison of the results of calculations of the formation and development of clouds corresponding to the real and model structures of the wind field in the atmosphere. In this case, the hierarchy property is considered, i.e., the interaction of convective clouds with the surrounding atmosphere, due to the structure of the wind field in the atmosphere. A three-dimensional unsteady model of thunderstorm clouds with a detailed account of microphysical processes was used for the research. The results of numerical experiments are presented in order to study the role of the interaction of convective clouds with the surrounding atmosphere.

Based on the data of field studies of dust aerosol concentration and meteorological parameters, the relationships between wind direction on the aeolian relief and the type of size distribution of transported dust microparticles have been revealed. Based on the field observations, two main cases can be distinguished related to the wind direction with respect to the line of dune ridges: tangential and frontal. At tangential wind direction slightly lower concentrations of fine dust particles are observed in comparison with the frontal wind direction case. This is attributed the electric field increases by increasing the dispersion of particle sizes and enhancing the tunnel effect of charge transfer from larger particles to smaller ones. Relative increase of coarse fraction at tangential wind direction is connected with involvement of larger particles from accumulation zone. The best conditions for generation of microparticles under the influence of electric field are relatively low wind velocities (close to critical). Therefore, during statistical evaluation of the indices in the power law of microparticle size distribution, a sample of data was taken at time moments with wind velocities from 3.5 to 5 m/s. This selection of data makes it possible to clearly highlight existing differences related to the physics of microprocesses in the near-surface soil–air layer for the two wind directions. A significant influence of mutual orientations of aeolian relief inhomogeneities and wind direction on the speed and size composition of dust aerosol emission was revealed. The development of accounting for such effects in the dust-emission blocks of atmospheric models seems relevant.

The results of full-scale aircraft studies of the relationship between microphysical characteristics and turbulence in supercooled clouds are presented. In zones with the simultaneous presence of supercooled liquid droplets and ice crystals, anisotropy of turbulent pulsations of air flow velocities is observed—the energy of vertical pulsations was greater than the energy of horizontal pulsations, sometimes by more than 2 times. The velocities of the updrafts exceeded 4.5 m/s, which create conditions for the growth of the liquid phase in the presence of ice crystals. In clouds with a mixed phase composition, in areas with increased turbulence intensity, there is a high probability of an aircraft falling into icing due to the presence in these zones of conditions for the generation and growth of the liquid phase in the presence of ice crystals, even for fairly low temperatures.

The article provides an analysis of the case of a mesoscale convective system using remote sensing data of the atmosphere: radar, satellite, lightning detection network and atmospheric electric field. The principle of complex diagnosis of the stages of development of the convective system with the identification of certain diagnostic signatures is applied. The features of the distribution of diagnostic parameters important for nowcasting of dangerous phenomena associated with the formation of stable severe convective structures are revealed.

This article is devoted to the analysis of changes in the air temperature and precipitation regimes in various climatic zones of the North Caucasus region. Time series of seasonal and annual temperatures in the surface layer of the atmosphere and precipitation for the period 1976–2019 were used to study climate change. It was found that in all climatic zones of the North Caucasus region there was a significant increasing in average annual and seasonal temperatures, especially during the summer season. The change in precipitation regime is not as obvious as the change in temperature. In all climatic zones, both an increase and a decrease in seasonal precipitation, mostly statistically insignificant, were observed. The trend resistance of meteorological parameters was assessed using the normalized range method and its quantitative indicator—the Hurst index. The Hurst index, calculated for the average seasonal temperatures and sum of precipitation, showed a high probability of persistence of the trends, especially for summer temperatures and autumn sum precipitation.

Kislovodsk Mountain Astronomical Station (KMAS) is one of the few observatories in the world where daily observations of the solar corona are carried out. The crown can be observed only in perfectly clear weather at altitudes of more than 2000 m. In this paper, the analysis of the number of days of observations of the corona and their relationship with the data of meteorological parameters in 1957–2022 is carried out. To do this, we used data from the Shatdzhatmaz meteorological station. Both seasonal and long-term variations are present in the data of meteorological parameters, as well as in the variations of corona observations. However, there is no obvious connection with the number of observation days of the corona. The number of days of corona observations can be used to estimate the level of atmospheric aerosols.

The multiyear series of mean monthly air temperatures at 65 meteorological stations in Central Africa are considered to assess the influence of climate change on the dynamics of multiyear mean values. Due to the spatial and temporal heterogeneity of observations, a methodology based on a sequential transition from more reliable to less reliable information, the assessment of the stability of nonstationarity indicators, the selection of areas homogeneous in climate change dynamics, and the quantification of the changes occurred depending on the type of mean value change and on the choice of effective climate models was developed. As a result, we received quantitative estimations of air temperature growth in different seasons, which reach 2.2–2.4 °C in southern mountainous and eastern regions in all seasons and summer monsoon in the coastal areas and spring intermonsoon period in the north. In the central part of the territory, the growth of average temperatures does not exceed 0.5–0.6 °C. Efficient climate models were also selected for the territory for the forthcoming assessment of future temperature.

A numerical study of thunderstorm development using 3D model is presented. An investigation of evolution features of cloud parameters and spatial distribution of the cloud characteristics during development is carried out. It is shown that maxima of studied parameters (cloud top height, vertical velocities, hydrometeor specific contents, lightning frequency, etc.) are reached at 50 min of simulation. The cloud appears in simulation domain after 26 min of simulation, maxima are reached in 25 min of cloud development. It is shown that most intensive convective processes take place during 50–60 min of simulation and reduce thereafter. Multilayer electrical charge structure is formed in the cloud. A polarity of the cloud inverts shortly after lightning activity beginning and returns back to the structure with main positive charge in the upper part of the cloud at mature stage of Cb development. A coincidence is established between location of regions with main volume charge and regions with highest specific hail content when discharges begin. A predominance of updrafts in velocity field of the studied thunderstorm during development stage is demonstrated. Downdrafts are formed in precipitation regions under the cloud base. At mature stage downdrafts are formed inside cloud and first appears in an anvil.

The article is devoted to measuring cloud water content. It considers various designs of sensors to measure liquid and total water content. Algorithms to calculate liquid and total water content are presented. As a result of research flights, data on capture coefficients for sensors of various designs were obtained in mixed-phase and droplet clouds.

In this work, an analytical solution of a two-dimensional model of thermal convection in a stratified atmosphere is obtained. Since the atmosphere is stratified, this leads to the fact that pressure, density and temperature decrease with height in a state of atmospheric statics. As a result of the heating of the Earth’s surface, the atmosphere is perturbed and thermal convection occurs. In this work, expressions for the stream function, perturbations of temperature, pressure, and velocity field are obtained.

The article is devoted to the comparison of statistical data of thunderstorm and hail activity on the territory of the Stavropol Region. As a result of data comparison, malfunctions of the North Caucasus lightning Direction Finding network were detected. High-frequency sensors were subject to particularly frequent malfunctions. At the same time, it was found that the discharges of the “cloud-to-earth” type tend to repeat cycles of hail activity.