This article analyzes air temperature and precipitation extremes in the Russian Federation for 1980–2022. Using ERA5 reanalysis data at grid points with a resolution of 0.25° × 0.25°, 27 climate extremeness indices recommended by the WMO Climate Change Detection Panel (CCD/CLIVAR) have been calculated based on hourly air temperature and precipitation data. The spatial distribution of the indices and their linear trends in various regions of Russia are analyzed. The following should be noted among the ongoing consequences of global warming in Russia: a widespread increase in the duration of the warm period, reaching a maximum rate on the Asian Arctic coast (up to 4–5 days/10 years), and a longer growing season, especially in the northern regions of the country. The number of hot days with maximum temperatures exceeding 25°C is also increasing. In the south of European Russia (ER), the increase rate reaches 7–10 days/10 years. At the same time, both the duration of the cold period (in the north of the country by 8–10 days/10 years) and the number of days with severe frosts below –20°C are decreasing. Overall, annual precipitation is increasing across Russia, with the exception of the southern grain-producing regions of the European part and Transbaikal. These regions are experiencing increasing summer aridity, and an increase in the maximum duration of dry periods (consecutive dry days with precipitation <1 mm/day) has been observed, at a rate of up to 4–5 days/10 years. The southern part of the Far East stands out in terms of the increase in annual heavy precipitation, with an increase of 10 mm/10 years, which can contribute to the occurrence of floods. The dynamics of temperature and humidity extremes in Russia are determined by the region’s location, proximity to the ocean, the nature of the terrain, and large-scale atmospheric circulation.
This work is devoted to comparing the levels of mass concentrations of near-surface aerosols PM2.5 and PM10 in Moscow and its suburbs, and also to assessing the contribution of the metropolis to aerosol pollution in suburban and urban air, taking into account seasonality and meteorological conditions. It is based on the data from continuous synchronous observations of aerosol composition in the surface layer of the atmosphere in the center of Moscow (city) and 55 km west of it, near Zvenigorod (suburb), obtained using identical sets of experimental equipment in 2020–2023. An analysis of weather conditions for 2014–2023 is carried out, and similarities and differences between meteorological parameters in the city and western suburb are established. It is revealed that easterly winds in the suburb (the advection of air masses and pollution from Moscow) are recorded on average in 10
This paper presents the results of a study of changes in large-scale extratropical circulation modes (the Arctic Oscillation (AO), Antarctic Oscillation (AAO), North Atlantic Oscillation (NAO), and Pacific–North American (PNA) pattern) in the 21st century based on simulations with the INM-CM6-M Earth system model developed at the Marchuk Institute of Numerical Mathematics, Russian Academy of Sciences. An analysis of the historical experiment (1985–2014) shows that the model accurately reproduces the spatial structures and amplitudes of these large-scale atmospheric circulation modes in the present-day climate, thereby justifying its use for future projections. For the SSP scenario experiments (2071–2100), we examined the spatial structures and explained variance, frequency of occurrence, and long-term trends of the modes. In high-emission scenarios (SSP5-8.5), the model projects a strengthening of the positive phase of the AO and NAO. The AAO exhibits more complex behavior linked to the competing influences of greenhouse gases and stratospheric ozone recovery processes. In contrast, the PNA shows a decrease in intensity in the future climate according to INM-CM6-M—a result that stands in opposition to projections from most other climate models.
The variability of daily sea level pressure anomalies in Russia has been studied using weather stations data and ERA5 reanalysis for period 1970–2023. Four variability ranges: interdaily (<3 days) range, synoptic (4–9 days) range, the range of stable weather patterns (SWP, 10–30 days), and the intramonthly (<30 days) range have been analyzed. In the modern period (2000–2023), the most significant reduction (15–25
In this paper, the exchange of sensible and latent heat in a turbulent air flow carrying salt droplets over a wavy water surface has been studied. Various air and water surface temperatures typical of polar and tropical cyclones have been considered. An eddy-resolving numerical model, where the equations for the air velocity, temperature, and humidity fields are solved in the Euler formulation simultaneously with the integration of the Lagrangian equations for the velocities, temperatures, and masses of individual droplets, has been used. Based on the calculation results, diameter distributions (i.e., spectra) of the sensible and latent heat fluxes from droplets to air, QS and QL, have been obtained. It has been shown that under tropical cyclone conditions, the fluxes are opposite in sign, QS < 0 and QL > 0, i.e., the droplets evaporate and cool the air. Furthermore, the latent heat flux predominates over the sensible heat flux. On the other hand, under polar cyclone conditions, the signs of both fluxes are positive, the droplets moisten and heat the air, and the sensible heat flux predominates, i.e., QS > QL > 0. In both cases, the total heat flux (enthalpy) from droplets to air is positive (QL + QS > 0) and increases with increasing droplet diameter. The resulting flux spectra can be used to estimate the relative contribution of droplets to sensible and latent heat fluxes from the ocean to the atmosphere under cyclonic conditions.
The effects of extreme temperatures and precipitation on the variability of CO2 and H2O fluxes in ecosystems across tropical, temperate, and polar regions during the warm season were investigated using ERA5 reanalysis data and data from the global FLUXNET and regional AmeriFlux networks. The study revealed that extremely high temperatures and heavy precipitation represent the most unfavorable conditions for plant community productivity in temperate and polar regions across all studied ecosystems. These conditions are accompanied by enhanced CO2 emissions to the atmosphere, largely driven by increased ecosystem respiration. Elevated temperatures weaken assimilatory processes and reduce primary production. Heavy precipitation exerts the strongest impact on CO2 fluxes by accelerating the decomposition of soil organic matter, increasing autotrophic and soil respiration, and consequently enhancing CO2 emissions. In the tropics, a similar response was observed with increased CO2 emissions across most biomes except savannas. This response is driven by the same processes as in extratropical regions. However, the response of CO2 fluxes to abnormally high temperatures differs in the tropics compared to temperate latitudes. In tropical ecosystems, enhanced CO2 uptake occurs during hot periods because anomalously high temperatures are not a limiting factor for plant growth under sufficient soil moisture conditions. The response of CO2 fluxes to low temperatures is more complex and varies even within the same biome, a pattern characteristic of all latitudinal zones. The key distinction in ecosystem responses to weather extremes is the dominant influence of temperature anomalies in temperate and polar regions, while precipitation extremes have a stronger influence in tropical regions. The response of water vapor fluxes to extreme temperatures is generally similar across latitudinal zones: evaporation increases with high temperatures and decreases with low temperatures. However, the response to extremely heavy precipitation differs between tropical and extratropical regions. In tropical regions, intense precipitation enhances evaporation. In temperate and polar regions, however, heavy precipitation reduces evaporation.
Thermokarst lakes are a significant source of methane, the second-most important greenhouse gas. At high latitudes, the rise in air temperature increases the total area of thermokarst lakes. This can enhance methane emissions from permafrost regions. The area of thermokarst lakes grows especially strongly in Western Siberia. We assess poorly studied local variability in methane emission from lakes in the region and its drivers, focusing on lake area. We measure methane flux at the summer peak on four small (0.1–1.0 km2) and five extra-small (<0.1 km2) lakes, considering possible variability within the lakes and two methane transport pathways to the atmosphere (diffusion and ebullition). Contrary to widely observed patterns, fluxes from larger lakes are higher than from smaller lakes: the mean methane flux measured by the chamber method is 4.1 and 2.1 mg CH4 m–2 h–1, and the median flux is 1.3 and 0.43 mg CH4 m–2 h–1 for small and extra-small lakes, respectively. Higher temperatures of bottom sediments, higher photosynthetic activity of algae, more intense ebullition in larger lakes, and equal depths and oxygen concentrations in lakes of different area categories could all explain the observed pattern. Results can improve predictions of methane emissions from the West Siberian tundra.
A method for calculating the radiative properties of ozone under vibrational–rotational nonequilibrium conditions is proposed. The method is based on the classical narrowband K-distribution model, which includes corrections for nonequilibrium. These corrections include vibrational and rotational distribution functions, as well as averaged Boltzmann functions over vibrational and rotational temperatures. To verify the method, a series of nonequilibrium calculations is performed and compared with the exact line-by-line (LBL) method in the spectral range of 500 to 1150 cm–1. The comparison, conducted over a wide range of pressures and translational, rotational, and vibrational temperatures, shows good agreement (within 5
Improving the quality of modeling the net radiation components is an urgent task that contributes to the development of modern models for numerical weather and climate forecasting. This study provides estimates of the accuracy of various computational schemes in the widely used ecRad radiation model based on comparisons with measurements of the RAD-MSU (BSRN) radiation complex at the Meteorological Observatory (MO) at Moscow State University for clear and cloudy conditions for the warm, snowless period from August 2021 to October 2023. For cloudless sky conditions, the reproduction of the total net radiation using CAMS aerosol reanalysis and ERA-5 reanalysis is satisfactory (error less than 4
Accurate ocean wave turbulence prediction is essential for maritime safety, offshore operations, and climate modeling. However, traditional models often overlook key meteorological factors, struggle with long-range dependencies, and fail to integrate spatial-temporal patterns effectively, leading to reduced predictive reliability. Extensive preprocessing further limits their adaptability across varying sea conditions. This study introduces DeepWave-TurbNet, a scalable and adaptive model for real-time ocean wave turbulence classification. Sensor readings from accelerometers, gyroscopes, and wave height sensors often suffer from misalignment due to varying sampling rates, while extreme wave conditions and sensor malfunctions introduce outliers. To address these issues, propose Z-Score KNN-Based Adaptive Filling (Z-KAF), which normalizes wave height, acceleration, and gyroscope data while handling missing values and removing outliers, ensuring robust feature representation. Following preprocessing, Pearson Correlation Coefficient (PCC) extracts meaningful relationships between sensor signals, eliminating redundancy. Feature selection is performed using DeepTurb-CNN-LSTM, where CNN captures local dependencies, and LSTM refines sequential learning, selecting the most relevant PCC-extracted features. A Softmax activation function classifies turbulence into Low, Moderate, and High levels, enabling precise decision-making. The proposed model achieves high performance, with RMSE of 0.0223 and MAE of 0.0153, significantly enhancing predictive reliability. DeepWave-TurbNet effectively mitigates traditional challenges, ensuring real-time turbulence assessment with improved accuracy, robustness, and efficiency.
Oxygen is vital for humans and animals. Nevertheless, until recently, undeservedly inadequate attention has been paid to trends and the variability of its content in surface air. This is due to the fact that the percentage of oxygen in the Earth’s atmosphere varies slightly, and measuring these small changes is rather difficult. However, even small changes in the oxygen content in inhaled air turn out to be quite significant for people, especially during heat waves, which are becoming more frequent and intensified in conditions of rapid climate change. This review is devoted to the history of knowledge about changes in oxygen content in the atmosphere and a review of research in recent decades, when the results of measurements of oxygen content in background and urban conditions became available.
Longwave radiation plays an important role in the middle and high latitudes’ climate formation. According to measurements of the RAD–MSU (BSRN) complex at the Moscow State University Meteorological Observatory, there were recorded cases with positive daily doses of net longwave radiation (NLR) for 23 days over the period from 2021 to 2024. All these cases were connected with warm or occluded fronts in condition of snow cover. For the two periods with positive NLR (December 19–21, 2023 and December 29–31, 2023), the experiments were performed with the ICON numerical weather prediction model. The positive NLR values were mostly reproduced by the model. We analyzed the factors (temperature profile, specific humidity, and cloud cover), which could influence the generation of positive NLR values. A comparison of the difference between the calculated and measured air temperature at various altitudes with the difference between the calculated and measured NLR values has revealed their statistically significant relationship up to a height of 500 m with correlation coefficients r > 0.5 and an increase in r to 0.7 in the lower atmosphere. A significant relationship with r = 0.55 was found between the difference in the low layer cloud cover amount and the difference in NLR. A closer relationship (r = 0.66) between these characteristics is observed with a 30-minute inertia. We discuss physical mechanisms, which are responsible for the revealed patterns.
Intense atmospheric vortices—tropical cyclones (hurricanes) and tornadoes—are among the most destructive natural disasters. A necessary element in these processes is rapid differential rotation, in which different parts of an object rotate around a common axis with different angular velocities, maintaining the structure not only in azimuth, but also vertically. One approach to studying these phenomena is numerical experiment, which has exceptional information content and the ability to obtain predictive results that cannot be achieved by any other methods. In this paper, based on direct numerical modeling of the Navier–Stokes system of equations, the formation of coherent column structures in a cubic closed volume in the presence of rotation (Coriolis force) and a constantly acting external force (forcing) is investigated. In these experiments, depending on the values of the rotation and forcing parameters, several types of motion of the fluid were obtained: a turbulent regime, a regime with the occurrence of several cyclonic vortices, and a regime with the occurrence of one large anticyclone. This paper establishes a mutual correspondence between the single-point statistics of vorticity, energy, and pressure values and the indicated types of flows. We show that using a rank-based approach and the occurrence frequencies of these quantities is productive in this way. The correspondence of the rank curves for a numerical and physical experiment conducted in a similar formulation is obtained. Without claiming to describe real atmospheric phenomena, the authors propose an original method for identifying different types of vortex flows based on the rank distribution of the occurrence frequencies of flow parameters.
Numerical experiments have been performed with the introduction of anomalies into the axisymmetric distribution of the velocity field generated by sources and sinks in a rotating circular channel with an inclined bottom (to simulate the β effect). The anomalies can be interpreted, on the one hand, as the influence of permanent centers of action (CAs)—zones of predominantly anticyclonic or cyclonic circulations—and, on the other, as a change in the intensity of the subtropical Hadley cell, which is accompanied by a weakening or strengthening of the trade winds in some sector of the near-equatorial atmospheric circulation and changes in the westerly transport in the middle latitudes. When simulating the influence of CAs, an effect of changing the circulation directions and the number of eddies was detected with an increase in the CA power above some critical values; here, small changes in the CA power lead to a reversal of the flow. Sectoral changes in the intensity of the external force effect in a certain range of values have an inhibitory effect on the speed of anticyclones passing through the channel (blocking). In this case, a significant part of the moving anticyclones may disappear or practically stop, or new quasi-stationary anticyclones may arise, although there are no noticeable changes in the visible picture of eddy propagation in the channel in the sector in which external intervention was carried out. The influence of the intensity of the external force action on the dynamics of eddy motion is also studied, in particular, when the movement of cyclones and anticyclones in the channel completely stops.
The Weather Research and Forecasting Model coupled with Chemistry (WRF-Chem) was utilized to examine the effects of aerosols on cloud microphysical properties and precipitation development. Three sensitivity tests were designed by changing the weight of anthropogenic emissions. The increase in the number concentration of aerosols resulted in the formation of more numerous and smaller cloud droplets, through which the optical properties of the clouds were changed. While shortwave cloud forcing is reduced in more polluted tests, changes in aerosol concentration have an insignificant incidence on longwave cloud forcing. The net radiative cloud forcing highlighted the contribution of aerosols to the greenhouse effect. In more polluted tests, cloud water content increased whereas rainwater content decreased, and as for ice water content; no real change was observed. It is found that; cloud fraction is reduced in more polluted tests. Results obtained showed a significant variation in precipitation as the aerosol concentration changed. The domain-averaged accumulated rainfall and the maximum accumulated rainfall in the clean and polluted tests decreased compared to that in the control test. When the weight of anthropogenic emission was increased by 10 times compared to that of the clean test, moderate and heavy rains increased compared to light rains in the Far North region of Cameroon; implying that in certain areas and under certain conditions, the inclusion of aerosols leads to an increase in rainfall, especially for moderate and heavy rainfalls.
A comparative analysis of multiyear measurements of organic carbon (OC), elemental carbon (EC), and CO carried out at the Zotino Tall Tower Observatory (ZOTTO) international background observation station in Central Siberia and at the St. Petersburg State University atmospheric monitoring station near St. Petersburg is presented. The values of background concentrations of these components are calculated, and the statistics of polluted and background periods are analyzed. It is shown that in both regions the total duration of periods with high aerosol carbon concentration is 50
The purpose of this work is to analyze the statistical characteristics that determine the group structure of surface waves in the Black Sea. The analysis used data from wave measurements taken from a stationary oceanographic platform located in the Black Sea. The isolation of the wave envelope, from which the groupiness factor GFH and the length group GLF were calculated, was carried out by several methods based on the Hilbert transform and the SIWEH function. It is shown that there is a statistical relationship between the excess kurtosis of surface elevations E and obtained by different methods GFH; the correlation coefficient of these parameters in the region E > 0.2 is in ranges from 0.35 to 0.49. The existence of a statistical relationship indicates that with the development of the group structure of sea surface waves, the likelihood of extreme waves increases. It is shown that the values GFH and GLF obtained within the framework of existing calculation methods can differ significantly quantitatively. At the same time, they equally reflect general trends in changes in the studied parameter, in particular, the dependence of GFH on the excess kurtosis of surface elevation.
The trends of air pollution in the resort region of Caucasian Mineral Waters (CMW) due to long-range transport in 1980–2024 according to reanalysis data and in 2025–2050 taking into account the most typical climate change scenarios of the SSP group (SSP2-4.5, SSP5-8.5) have been studied. The study is carried out on the basis of solving the conjugate problem of transport and diffusion of pollutants in the atmosphere, calculating the functional characterizing the total amount of pollutants incoming the region, and calculating the air pollution index characterizing the direction of pollutants entering region. The results show no significant changes in the long-range transport and or quantity of pollutants entering in this way (in the case of unchanged intensity of their sources) for the CMW region in both the historical (1980–2024) and future (2025–2050) periods, taking into account climate scenarios. In terms of the impact of climate change, it can be expected that, until 2050, favorable air quality and health potential in the resort region will remain at the same level. At the same time, nearby and remote sources of pollutant emissions require constant monitoring and control.
Estimates of the variability of the electric field potential gradient under the influence of clouds of the main forms were obtained using meteorological and atmospheric–electrical observations over a 15-year period (2006–2020) in Tomsk. A comparative analysis and comparison of these estimates with similar estimates for electrically unperturbed atmospheric conditions (fair-weather conditions) was carried out. It was found that clouds of all main forms, including the upper tier, have a significant effect on the surface electric field, leading both to a shift in the distribution of the potential gradient values towards negative values, and to a change in their dispersion. An analysis of the histograms of the surface electric field potential gradient values during the passage of the main precipitation-forming clouds (Cb, Ns, St, As) showed the presence of heavy tails in their distribution. In the distribution of the potential gradient during the passage of nimbostratus clouds, a clearly expressed secondary mode is observed, which, presumably, may be associated with the development of masked convection.
Over the past two decades, marine heatwaves (MHWs) in the Indian Ocean have significantly increased in both frequency and intensity. The present study focuses on the causes, impacts, and trends of marine heatwave (MHW) events in specific regions like Somalia, Oman, Visakhapatnam, Head Bay of Bengal (HBoB), and Java- Sumatra (JS) of the Indian Ocean (IO) during 1981–2023. More than 100 MHW events, exceeding the 90th percentile threshold, have been noticed at the above regions. Variations in intensity, duration, and frequency analyzed for each location. Our findings shows an average of three MHW events per year, with a notable increase of 1.5 events per decade. During 2015 a very strong MHW event occurred at Somalia region, it continued up to 80 days with a maximum intensity of 2.88°C and a mean intensity of 1.46°C (above climatology mean). Furthermore, we also examined the recurrence patterns of MHW in various regions of the Indian Ocean.
