Research and Production Association Typhoon

The article presents the experience of training foreign students of Rosatom State Corporation’s flagship universities at the MEPhI Resource Center. It is shown that over the period 2018–2024, more than 500 bachelor’s, specialist and master’s students from 33 countries studying at the five largest flagship universities of the state corporation (VSU, MEPhI, SPbPU, TPU, UrFU) underwent practical training in English and Russian at the Resource Center of Obninsk Institute for Nuclear Power Engineering (IATE MEPhI). Students were trained in six educational programs of 13 and 14 specialty groups. In the field of non-energy application of nuclear technologies, practice-oriented training at the Resource Center is carried out to a greater extent on radiation technologies in agriculture and the food industry. High results of cooperation in training foreign students in the field of agro-nuclear technologies between the IATE MEPhI and the National Research Center “Kurchatov Institute” – RIRAE were noted. Practical training of students at RIRAE is carried out on a unique gamma-installation GUR-120 for irradiation of agricultural raw materials and food products for the purposes of phytosanitary and microbiological safety, increase in shelf life, radiation stimulation. The competencies acquired by students in the field of agricultural radiation technologies are in demand by them when applying for jobs in the Centers of Nuclear Science and Technology. The interaction of the Resource Center of the IATE MEPhI and the leading research institutes of Obninsk in training foreign students is the basis for the development of the international scientific and educational center “Obninsk Tech” for training personnel for foreign businesses of the State Corporation “Rosatom” in the nuclear industry and related areas of application of nuclear technologies.

Horizontal inhomogeneities of the gravity field lead to the occurrence of horizontal inhomogeneities of the density and pressure fields in a stratified medium. Taking into account dissipative factors, this causes the appearance of flows. In a number of previous works, the authors theoretically studied atmospheric disturbances caused by inhomogeneities of the gravity field. It is obvious that qualitatively similar effects, in principle, should also exist in a stratified aquatic environment (primarily in the ocean). However, the numerical values of the media parameters and dimensionless determining parameters vary greatly. This article is intended to estimate the intensity of the flows appearing in the case of the aquatic environment. A two-dimensional problem of linear stationary disturbances in a stably stratified medium in an inhomogeneous gravity field above a solid horizontal surface is considered. Coriolis accelerations are taken into account, the Boussinesq approximation and f-planes are used; the coefficients of viscosity and thermal diffusivity are assumed to be constant. The consideration is limited to one horizontal harmonic of disturbances. The essential dimensionless determining parameters are analogs of the Rayleigh (R) and Taylor (Ta) numbers, in which the horizontal scale of the harmonic under consideration appears as a spatial scale. Separation of variables leads to a bicubic characteristic equation, the roots of which, generally speaking, are expressed rather cumbersomely. Situations are considered when the horizontal scales of gravity field inhomogeneities are greater than or about 100 km. The numbers R and Ta are very large, which makes it possible to significantly simplify the problem, since it is sufficient to limit ourselves to the relatively simple asymptotic of solutions to the characteristic equation. An approximate analytical solution is found. The largest amplitude is the horizontal vortex component of the emerging flow, directed along the horizontal inhomogeneities of the gravitational field. Its value can be of the order of the product of the buoyancy frequency of the stratified medium and the amplitude of vertical deviations of the isosurfaces of the gravity potential. According to the given estimate, the amplitude of horizontal velocity disturbances can reach values of about several centimeters per second depending on the stratification.

<strong class="journal-contentHeaderColor">Abstract.</strong> Mercury (Hg) is a toxic substance and accumulates in the biosphere causing negative impacts to the well-being of flora and fauna as well as humans. In this study, we analysed the long-term time-series (2001&ndash;2013) of the gaseous elemental mercury measurements at the Arctic station Amderma (Russia). We explored the influence of long-range atmospheric transport of gas-phase mercury into the Arctic from the volcanic eruptions in Iceland in 2010&ndash;2011. The change in the dynamics of atmospheric Hg concentration was identified. Contrasting time periods of 2001&ndash;2009 and 2010&ndash;2012 periods, we quantified a negative trend of -0.66 ng for the earlier period and a positive trend of +0.97 ng for the latter period. Our analysis highlighted that the elevated Hg concentrations at Amderma were associated with active volcanic eruptions in Iceland, namely Eyjafjallaj&ouml;kull and Gr&iacute;msv&ouml;tn in 2010 and in 2011, respectively. The observed Hg concentrations were in the range of 1.81&divide;2.58 ng m^&minus;3 in Apr&ndash;Jun 2010 and 1.81&divide;3.31 ng m^&minus;3 in May&ndash;Jun 2011 compared with the annual average Hg concentrations of 1.51&plusmn;0.41 ng m^&minus;3. This is the first time to detect such an elevated Hg concentration during the active volcanic eruptions measured over 3200 km away from the eruption source. The calculated atmospheric backward trajectories (at altitudes of 500, 1500 and 3000 meters above sea level) underlined the occurrence of the Hg elevated concentrations and confirmed the atmospheric transport from the areas of these two volcanoes. Therefore, it can be assumed that these volcanoes were the main source of the increased Hg concentrations at the Amderma station resulted due to the long-range atmospheric transport of the volcanic emissions.

The helicity of atmospheric disturbances caused by inhomogeneities in the gravity field is theoretically estimated. For this purpose, a three-dimensional stationary analytical model of linear disturbances introduced by spatial inhomogeneities of the gravity field into the background geostrophic flow of a stratified rotating medium (atmosphere) was used. From the solution found, it follows that in highly anomalous regions the amplitude of the helicity of emerging disturbances can be noticeable.

The Cross-track Infrared Sounder (CrIS) observations (O) contributed greatly to numerical weather prediction. Further contribution depends on the success of all-sky data assimilation, which requires a method to produce realistic cloud/rain band structures from background fields (i. e., 6-h forecasts), and to remove large biases of all-sky simulation of brightness temperature in the presence of clouds. In this study, CrIS all-sky simulations of brightness temperatures at an arbitrarily selected window channel within Typhoon Hinnamnor (2022) are investigated. The 3-km Weather Research and Forecasting model with three microphysics schemes were used to produce 6-h background forecasts (B). The O&amp;#8722;B statistic deviate greatly from Gaussian distribution with large biases in either water clouds, or thin ice clouds, or thick ice clouds within Typhoon Hinnamnor. By developing a linear regression function of three all-sky simulations of brightness temperature from 6-h forecasts with three microphysics schemes, the O&amp;#8722;B statistics approximate a Gaussian normal distribution in water clouds, thin ice clouds and thick ice clouds. Taking the regression function that is established by a training dataset to combine 6-h background forecasts at later times, the cloud/rain band structures compared much more favorably with CrIS observations than those from an individual microphysics, and the O&amp;#8722;B biases are significantly reduced. The work in this study to quantify and remove biases in background fields of brightness temperature and generating realistic typhoon cloud/rain band structures in background fields will allow a better description of center position, intensity and size to improve typhoon forecasts.

Digital twins are emerging in power electronics as a tool for optimized design, fast prototyping, and smart maintenance, given the increasing demand in terms of high power density, reliability, and low cost. A power electronics digital twin can be regarded as a virtual representation of a power electronics system, embodied by a high-fidelity model running in real time, of which the states and model parameters are updated based on the feedback from the sensors or their data fusions. Digital twin models are developed in multiple domains and run in real time or even faster than real time. The data collected from the physical entities are transferred with controlled latencies and quality, and then processed to iterate the models to represent physical power electronics from application-oriented views. However, due to the nonlinearities and fast switching behaviors of power electronics, one significant challenge is to ensure high fidelity and fast computation simultaneously, which stimulates the real-time simulation (RTS) of power electronics with an ultralow time step. Moreover, the electrical, thermal, and electrothermal aspects shall all be considered to improve the model’s accuracy. To consider the uncertainties, the parameters of the digital twin models are either identified by advanced optimization algorithms or represented by probabilistic expressions. To make it possible, real-time communication should be established between the physical and digital twins. Empowered by modern Internet of Things (IoT) technology, many sensor signals can be transferred in a timely fashion to ensure real-time capability of the digital twin. The digital twin gives insightful information about its physical counterpart based on which smart decisions can be made to improve the design, prototyping, control, and lifecycle management of power electronics converters and systems. In this article, we review the digital twin of modern power electronics, and get an insight into its enabling technologies and possible applications.

Due to their local, sudden nature, which complicates forecasts, squalls often cause significant material damage and are classified as extreme weather events. Diagnosing squalls and increasing the accuracy of modeling to improve their operational forecasting is very relevant. Determining the main characteristics of squalls by diagnosing particular cases and analyzing such cases is of great interest in order to establish causes of extreme events, which are still insufficiently studied. The source of obtaining primary information on the characteristics of squalls is the processing of a large array of observational data from a high-altitude meteorological mast (HMM) of the Institute of Experimental Meteorology of the Federal State Budgetary Institution Research and Production Association Typhoon, presented in this article for 2014–2023. Such experimental data on a number of long-term observations on the HMM has made it possible, after processing and analyzing the velocity fields, to fix intense squalls passing through the sector. The main characteristics of these special cases of squalls are obtained and analyzed, some of which are simultaneously simulated using the WRF-ARW nonhydrostatic mesoscale atmospheric model, adapted for the observation area; verification is also carried out with data from field experiments. A good agreement between the results and observational data for the particular case of squalls is shown.

This study assessed total hydrocarbon content and polycyclic aromatic hydrocarbon content in Grönfjord (the Greenland Sea, Svalbard). The field study was held in marine expeditions of research vessel “Barentsburg” by the North-Western Branch of the Federal State Budget Institution, Research and Production Associaton «Typhoon» in summer periods of 2012 to 2022. In the framework of the field works simultaneous measurements of hydrological and hydrochemical characteristics of the water column were done. The data was analyzed using standard procedure in purpose to gather new information about the levels of hydrocarbons (measured as total hydrocarbon contents), polycyclic aromatic hydrocarbons. The results showed pronounced interannual variations of total hydrocarbon contents and polycyclic aromatic hydrocarbons concentrations. Supposed that local natural sources contribute to elevated polycyclic aromatic hydrocarbons and total hydrocarbon content levels both in water and in sediments, the levels of contamination do not signify exclusively anthropogenic influence on the sea-body. At the same time, some local elevated petroleum hydrocarbons concentrations, which were detected in the surface water layer, may be a sign of existing industrial activity affecting the waters of the fjord. Continuity of tasks starting from earlier expeditions indicates that many processes in the Norwegian Sea, Greenland Sea require further research.

Abstract—The paper presents the results of a study of spatiotemporal variability of the characteristics of the wind field in the free atmosphere of the Northern Hemisphere in the SEVIRI radiometer field of view of European geostationary meteorological satellites of the second generation Meteosat 8–Meteosat 11 in the time interval 2007–2021. It is noted that the maximum wind speeds, as well as the maximum average monthly and seasonal anomalies of the wind speed modulus, are observed over the Atlantic. A feature of the temporal variability of the area-averaged wind speed modulus is revealed, which consists in a change in the sign of the trend at the turn of 2015–2017 from positive to negative. At the same time, positive linear trends in the time intervals from 2007 to the points of a change in the sign of the trend over the Atlantic, the entire region under consideration and Eurasia, including the European territory of the Russian Federation, are significantly different from zero with a probability of more than 95% and the negative trend is significant only over the Atlantic. A high correlation was noted in the area of seasonal wind speed variations with the area of Arctic sea ice and temperature characteristics of the troposphere at levels of 500 and 200 hPa. Based on the analysis of the relationship between wind speed variability and the main climatic characteristics and large-scale atmospheric processes, a scheme is proposed for the effect of the accelerating reduction in the area of Arctic sea ice associated with global warming on wind speed in the free atmosphere.

—The results of experiments in the Large Aerosol Chamber of RPA Typhoon revealed the appearance of new aerosol particles larger than 15 nm in an aerosol-free volume of atmospheric air isolated from the external environment in darkness 20 min after the air purification. The generation of new particles is associated with the possible presence of precursor gases in the atmospheric air, which, under the influence of cosmic rays penetrating into the chamber, turn into aerosols. The experimentally observed evolution (over several days) of the size spectrum of the resulting particles shows that the generation of new aerosol particles lasts no more than 20 hours. During the evolution, the particles become larger and reach more than 100 nm size. After repeated purification of the air inside the chamber with the removal of newly generated aerosols, no new particles were detected for 10 days.