Представлены результаты расчетов метеорологических параметров и качества атмосферного воздуха во время аномально холодной погоды (T ниже - 20 оС) в г. Томск, полученные с помощью комплекса моделей WRF/CAMx. Результаты расчетов сравниваются с наблюдениями ультразвуковых метеостанций и температурных профилемеров ЦКП «Атмосфера», а также TOR-станции ИОА СО РАН. Для оценки уровня загрязнения атмосферы используется адаптированный Common Air Qiality Index (проект CiteairII, поддерживаемый ЕС), рассчитанный по ежечасным концентрациям.

Для краткосрочного прогноза опасных метеорологических условий и качества атмосферного воздуха над ограниченной территорией с крупными населенными пунктами предлагается математическая модель и эффективный численный метод, ориентированный на применение суперкомпьютеров. Математическая модель включает модель переноса примеси с сокращенным химическим механизмом и негидростатическую мезомасштабную метеорологическую модель с современной схемой параметризации микрофизики влаги. Приведены примеры успешного применения разработанной моделирующей системы при численном прогнозировании ухудшения качества приземного воздуха при слабом ветре и температурных инверсиях, а также при предсказании некоторых опасных погодных явлений.

The relevance of the study is associated with the development and validation of the TSUNM3 model for numerical local weather prediction. The results of its application over a limited territory of the Siberian region are presented. A study of the characteristics of an urban "heat island" and the analysis of the reliability of forecasting precipitation have been carried out. The calculation results are compared with observations of the atmospheric boundary layer parameters obtained with meteorological instruments of the Joint Use Center "Atmosphere" at the Institute of Atmospheric Optics of the Siberian Branch of the Russian Academy of Sciences.

На основе наблюдений ЦКП «Атмосфера» ИОА СО РАН рассмотрено содержание CO, O3 и PM10 при разных метеорологических величинах. Показано, что существует неслучайная корреляционная связь между содержанием указанных примесей и скоростью ветра, включая разные его направления, температурой и давлением воздуха.

Dangerous fire elements are forest fires, which annually cause enormous damage of a social and economic nature. The territory of the Tomsk region is located in the taiga zone of Western Siberia; the forestry industry is one of the leading in the economic complex. For the period 2012-2019 here more than 20 thousand hectares of forest plantations died from fires. In this regard, the climatic assessment of trends in conditions favorable to the occurrence of fires in specific territories is of considerable scientific and practical interest. The purpose of this work is to assess climatic changes in meteorological factors for the Tomsk station affecting the potential for a fire, and an economic interpretation of the events taking place. To assess the fire hazard, special indicators (indices) have been developed, which take into account, first of all, the temperature and humidity conditions of the time period. In our study, the CI indicator (complex indicator) is used. The fire hazard is the higher, the higher the CI value. The economic indicators of the degree of adaptation of the forest complex to modern climatic conditions are estimated. The conditions at Tomsk station during rainless periods during fire hazardous seasons (April - September) from 1924 to 2015 were considered. Determined rainless periods and their characteristics - the beginning and end, the duration of the period without precipitation, air temperature (average and maximum), minimum relative humidity and wind speed (average and maximum). Analysis of the fire hazard index revealed an increase in the fire hazard of forests in Tomsk over the past 90 years. There is a statistically significant increase in the number of days with meteorological conditions that create preconditions for the occurrence of forest fires. During the warm half of the year, the sum of the flammability indices increased significantly. The number of days with a high forest fire hazard has increased and the number of days with a low fire hazard has decreased. The presented quantitative indicators of the fire hazardous season confirm a certain influence of the climatic factor on the frequency of forest fires in the region. In unfavorable fire-hazardous seasons, an important role is played by the technical component (equipment and technical means) and technological equipment (methods of work, rules of procedure) of forestry organizations. With the existing natural recurrence of fires in the region, the necessary conditions for improving economic indicators are a decrease in the cost of forest protection measures and a decrease in the coefficient of unforeseen losses.

This paper presents a parallel algorithm for numerical solution of equations for the non-hydrostatic mesoscale meteorological model TSUNM3. To justify the choice of the Message Passing Interface technology, computational experiments were performed to compare the effectiveness of the following parallelizing technologies: MPI, OpenMP, OpenACC, and CUDA. 2D decomposition of the gridded domain for the TSUNM3 model has been carried out with MPI technology. It allows for a numerical forecast for the next day in 17 minutes of CPU time on 144 cores of the TSU Cyberia computing cluster.

The paper presents the results of studying the influence of the development of meteorological situation in clear weather with a weak wind on the level of atmospheric surface air pollution in the city of Tomsk (Russia). Mesoscale meteorological and photochemical models with a new kinetic scheme were applied to the analysis. The main local weather conditions were identified, in which numerical calculations show increased values of the air pollution index. The numerical predictions have confirmed an increase in the ground-level concentration of pollutants in the presence of temperature inversion or isothermy.

Based on the analysis of meteorological observations on the territory of the Tomsk region in the last 20 years, new climatic characteristics of the spatio-temporal changes in ground icing (GI) have been obtained. Information is provided on the intensity of the types of deposits (large diameter, weight), the duration of the growth phase and, in general, a phenomenon that is important for the transport and energy industries. The revealed meteorological and synoptic conditions for the formation of various types of ground icing are necessary both for a more confident diagnosis and for improving the methods for predicting them. A large variation in the frequency of occurrence of GI is observed across the territory - ten or more times, and over the years - from two to seven times. The smallest number of GI is noted in the southeastern part, most often occur in the northern part of the region, which is extremely inaccessible for transport. In recent years, the rate of change in the repeatability of types GI has different signs: grained rime (GR) - slightly increases at most stations, glaze (G) - decreases; crystal rime (CR) also decreases. The recurrence of all types of GI in Tomsk has been declining. The non-stop duration of glaze and grained rime in most cases does not exceed one day, crystal rime, moist snow (MS) and ice-crusted ground (ICG) - two days. The maximum duration of ice-crusted ground is ten days, for other types of GI - up to two days. The intensity of G and MS most often does not exceed 16 mm, a maximum of 44 mm; GR and CR - respectively, does not exceed 4 mm with a maximum of up to 9 mm. The occurrence of GI was observed both in cyclonic and anticyclone baric fields: in the first, GI and MS prevail, and secondly, CR and GR. GI in 77,3% of cases were observed in homogeneous air, 22,7% - on atmospheric fronts. The homogeneous air mass GI (especially CR) most often occur in anticyclones at the maximum developmental stage, or in low-gradient anticyclone fields, but there are cases in decaying or regenerating anticyclones. G was rarely observed in the rear parts of cyclones and low-gradient cyclonic fields, and MS in an anticyclone. The GR and MS often occur during the passage of warm, and G - cold sections of the Arctic fronts. CR was predominantly in homogeneous air mass. It is necessary to note the insufficient number of observation stations for the phenomena for high-quality service of the regional economic complex, especially taking into account the development strategy of the oil and gas industry and its road, pipeline and electricity supply. The emergence of intramass GI could not have been detected by such a rare network of hydrometeorological stations. We think that the results of the research can be used in various applications to clarify the climatic characteristics of GI, as well as in predicting the effects of ground icing.

The paper describes the mathematical formulation and numerical method of the TSUNM3 high-resolution mesoscale meteorological model being developed at Tomsk State University. The model is nonhydrostatic and includes three-dimensional nonstationary equations of hydrothermodynamics of the atmospheric boundary layer with parameterization of turbulence, moisture microphysics, long-wave and short-wave (solar) radiation, and advective and latent heat flows in the atmosphere and at the boundary of its interaction with the underlying surface. The numerical algorithm is constructed using structured grids with uniform spacing in horizontal directions and condensing to the Earth surface in the vertical direction. When approximating the differential formulation of the problem, the finite volume method with the second order approximation in the spatial variables is used. Explicit-implicit approximations in time (Adams–Bashforth and Crank–Nicolson) are used to achieve second-order accuracy in time. The paper presents results of numerical forecasting of the main meteorological parameters of the atmosphere (temperature, humidity, wind speed and direction) and precipitation in different seasons in the Siberian region. The models were tested with the help of observations obtained using the Volna-4M sodar, MTR-5 temperature profile meter, and Meteo-2 ultrasonic weather stations of the Atmosfera Collective Use Center. The improved TSUNM3 model is shown to adequately reflect the precipitation time and intensity. However, in some cases, the times of its beginning and end do not always coincide, the difference can reach several hours. The precipitation phase state is reflected reliably. Over 70% of precipitation cases are confirmed by numerical calculations. The model satisfactorily predicts temperature and humidity characteristics. The quality of the precipitation forecast model is comparable to the modern mesoscale models, such as the Weather Research and Forecasting (WRF) model.

Spatial and temporal characteristics of climate determining snow accumulation at the motor roads of Tomsk region in 1966-2017 are analyzed in the study.Results of the analysis of snow cover, wind and snowstorm conditions are presented.A certain increase in snow-cover depth is found in the south of Tomsk Region, while decrease is detected in the northern part.Both number of days with snowstorm and average duration of snowstorms have decreases due to reduction in the wind speed.

To solve problems of energy saving and reduce the cost of services that are essential for human comfort in buildings, the calendar duration of the heating season (HS) in Tomsk has been estimated on the basis of an analysis of temperature characteristics of the environment at the HS start and end. Monthly data of meteorological observations for the cold periods in 2011-2018 and existing methods (Ped's and SNiP) for determining the dates of the stable transition of the daily mean temperature through 8 °C are used in addition to the dates of actual heating supply in Tomsk. As an indicator of human comfort, along with the usual daily mean temperature, the index of radiation-equivalent-effective temperature (REET) is used. It has been revealed that using Ped's method for determining the duration of the heating season, which leads to less discomfort from heat or cold for the population, is economically feasible. The calculated characteristic of heating of degree-days (HDDs) is equal to 5800, which confirms a previously revealed tendency to climate warming in the study region.

An approach to the detection of aircraft icing zones based on information from MODIS (Terra, Aqua) and ATOVS (NOAA18, NOAA19, MetOp) radiometers is presented. The prospects of using such an approach are demonstrated for Tomsk airport, which has a 2011-2017 PIREP data bank. The annual icing frequency in the vicinity of Tomsk is rather high and amounts to 14% of days per year, increasing by 30% in October to December according to the PIREPs. The following satellite products are used: 1.375 and 8.50 μm channel information, cloud-top temperature, cloud water path, temperature and specific humidity vertical profiles. The temperature and humidity profiles restored from the satellite data make it possible to identify icing zones on a three-dimensional scale using physical and statistical regularities. An example of a severe icing diagnosis based on the Godske method and a computed intensity of icing in-flight at 250 kph is considered in the paper. A combined analysis of the materials confirms that the identification of icing zones is satisfactory.

We present the results of applying the MTP-5PE meteorological temperature profiler for determining the spatial zones of possible aircraft icing in Tomsk airport on March 17, 2013. The spatial zones were determined using the RAP-algorithm, the Godske formula, as well as the AMIS-RF data for retrieving the humidity profile. The RAP algorithm and the Godske formula are shown to predict similar locations of spatial zones of possible aircraft icing. However, the RAP results are closer to the actual icing reports available from aircraft crews.

In the paper, the possible use of a WRF mesoscale model for the detailed restoring of a temperature profile in the atmosphere boundary layer (ABL) during winter anticyclone is studied. The correctness of air temperature modeling as well as the possible use of a WRF model for predicting a vertical temperature distribution was shown.

Numerical simulation results obtained for meteorological conditions in the area of Bogashevo airport and the city of Tomsk using the Weather Research & Forecasting (WRF) mesoscale system are presented. The main attention is paid to choosing the parameterization of microphysical processes adequate for conditions of Western Siberia with the aim to obtain a reliable forecast of intense rainfalls. The performed comparison of predicted and factual data on precipitation and cloudiness demonstrated good possibilities of the model for forecasting precipitation and dangerous events for aviation. The ETA microphysics parameterization yielded the best results.

We describe the measurement and calculation complex for monitoring and forecasting the meteorological situation at airports, which comprises MTP-5PE meteorological temperature profiler, WXT520 Vaisala Weather Transmitter, main and remote terminals for managing the complex, network data storage, two high-resolution meteorological models, server, and SKIF Cyberia cluster at Tomsk State University. The paper presents the results of monitoring and forecasting the atmospheric temperature profile and surface wind speed and direction, pressure, humidity, and temperature for the previous winter, when different extreme weather events were observed in Bogashevo airport. It is shown that the measured and calculated vertical temperature profiles in the lower part of the atmospheric boundary layer show high level of qualitative and quantitative agreement of results.

Data on temperature inversions in the vicinity of Tomsk on the basis of MTP-5PE profiler data carried out at the IMCES SB RAS were summarized. It is shown that during persistent long-lived powerful anticyclones there is high recurrence of temperature inversions - they occur every day, or 90% of the time. A few characteristics of inversions observed in the region of the Bogashevo airport are presented.