Pub Date : 2023-12-25DOI: 10.1134/s0001433823060075
Y. P. Perevedentsev, N. V. Ismagilov, N. A. Mirsaeva, V. V. Guryanov, A. A. Nikolaev, K. M. Shantalinsky
Abstract
Based on the data of ERA5 reanalysis, the dates of spring and autumn changes in the stratospheric circulation on isobaric surfaces of 30, 20, and 10 hPa in the latitude zone of 30°–90° N in the period 1979–2020 have been obtained. Of the 42 cases of spring changes, 10 are early, 15 are middle, and 17 are late. The spread in the dates of spring changes on the surface of 10 hPa is 69 days. Most often, the spring changes of the circulation occurs from top to bottom; in some years, the delay of spring changes on the surface of 30 hPa relative to the surface of 10 hPa reaches 22–25 days. Autumn change takes place from the bottom up, and their terms at the 3 levels under consideration are close to each other. The relationship between the timing of the spring changes of the stratospheric circulation with solar activity and large sudden winter stratospheric warming is shown. An analysis of the fields of anomalies of daily temperature values and zonal wind velocity in the 1000-1 hPa layer in the period of January–May showed their significant spatiotemporal difference in the case of early and late spring changes. Thus, foci of positive anomalies of temperature and wind speed are formed initially in the upper stratosphere and then shifted from top to bottom. The interrelations between the layers of the atmosphere in different seasons are considered.
{"title":"Seasonal Changes in Stratospheric Circulation and Interactions between the Troposphere and the Stratosphere","authors":"Y. P. Perevedentsev, N. V. Ismagilov, N. A. Mirsaeva, V. V. Guryanov, A. A. Nikolaev, K. M. Shantalinsky","doi":"10.1134/s0001433823060075","DOIUrl":"https://doi.org/10.1134/s0001433823060075","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Based on the data of ERA5 reanalysis, the dates of spring and autumn changes in the stratospheric circulation on isobaric surfaces of 30, 20, and 10 hPa in the latitude zone of 30°–90° N in the period 1979–2020 have been obtained. Of the 42 cases of spring changes, 10 are early, 15 are middle, and 17 are late. The spread in the dates of spring changes on the surface of 10 hPa is 69 days. Most often, the spring changes of the circulation occurs from top to bottom; in some years, the delay of spring changes on the surface of 30 hPa relative to the surface of 10 hPa reaches 22–25 days. Autumn change takes place from the bottom up, and their terms at the 3 levels under consideration are close to each other. The relationship between the timing of the spring changes of the stratospheric circulation with solar activity and large sudden winter stratospheric warming is shown. An analysis of the fields of anomalies of daily temperature values and zonal wind velocity in the 1000-1 hPa layer in the period of January–May showed their significant spatiotemporal difference in the case of early and late spring changes. Thus, foci of positive anomalies of temperature and wind speed are formed initially in the upper stratosphere and then shifted from top to bottom. The interrelations between the layers of the atmosphere in different seasons are considered.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":"28 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-25DOI: 10.1134/s0001433823060099
V. P. Shutyaev, E. I. Parmuzin
Abstract
The methodology of variational assimilation of observational data for the reconstruction of the initial state and heat fluxes for the mathematical model of sea thermodynamics is presented. An algorithm is developed for estimating the sensitivity of a model solution to errors in observational data. The calculation of the gradient of the response function of the model solution is based on the use of the Hessian of the cost functional. The results of numerical experiments for the Black Sea dynamics model developed at the Institute of Numerical Mathematics, Russian Academy of Sciences, are presented.
{"title":"Variational Data Assimilation for the Sea Thermodynamics Model and Sensitivity of Marine Characteristics to Observation Errors","authors":"V. P. Shutyaev, E. I. Parmuzin","doi":"10.1134/s0001433823060099","DOIUrl":"https://doi.org/10.1134/s0001433823060099","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The methodology of variational assimilation of observational data for the reconstruction of the initial state and heat fluxes for the mathematical model of sea thermodynamics is presented. An algorithm is developed for estimating the sensitivity of a model solution to errors in observational data. The calculation of the gradient of the response function of the model solution is based on the use of the Hessian of the cost functional. The results of numerical experiments for the Black Sea dynamics model developed at the Institute of Numerical Mathematics, Russian Academy of Sciences, are presented.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":"14 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-25DOI: 10.1134/s0001433823060129
S. S. Vlasenko, O. A. Ivanova, T. I. Ryshkevich, E. F. Mikhailov
Abstract
The results of a back-trajectory analysis of 9-year (2013–2021) measurements of organic (OC) and elemental (EC) aerosol carbon concentrations made at the atmospheric monitoring station near St. Petersburg (Peterhof, 59.88° N, 29.83° E) are presented. The spatial location of sources was estimated by the concentration weighted trajectory (CWT) method in the geographic area 16°–44° E × 48°–68° N. The data allow us to identify the territories with the strongest OC and EC emissions and estimate the seasonal variability of these emissions. In particular, the estimates show that the most intense sources of OC and elemental aerosol carbon in the studied region are located in the Volga-Oka interfluve and on the adjacent territories. It is demonstrated that linear regression coefficients between CWT function values for OC and EC differ for different regions and seasons and may indicate the prevailing type of sources of carbon-containing aerosol particles.
{"title":"Estimation of Spatial Distribution of Potential Sources of Carbonaceous Aerosol from Local Measurements near St. Petersburg","authors":"S. S. Vlasenko, O. A. Ivanova, T. I. Ryshkevich, E. F. Mikhailov","doi":"10.1134/s0001433823060129","DOIUrl":"https://doi.org/10.1134/s0001433823060129","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of a back-trajectory analysis of 9-year (2013–2021) measurements of organic (OC) and elemental (EC) aerosol carbon concentrations made at the atmospheric monitoring station near St. Petersburg (Peterhof, 59.88° N, 29.83° E) are presented. The spatial location of sources was estimated by the concentration weighted trajectory (CWT) method in the geographic area 16°–44° E × 48°–68° N. The data allow us to identify the territories with the strongest OC and EC emissions and estimate the seasonal variability of these emissions. In particular, the estimates show that the most intense sources of OC and elemental aerosol carbon in the studied region are located in the Volga-Oka interfluve and on the adjacent territories. It is demonstrated that linear regression coefficients between CWT function values for OC and EC differ for different regions and seasons and may indicate the prevailing type of sources of carbon-containing aerosol particles.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":"13 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-25DOI: 10.1134/s0001433823060105
A. V. Slunyaev
Abstract
Based on the direct numerical modeling results of irregular nonlinear waves on the surface of deep water within the framework of three-dimensional potential equations of hydrodynamics, the contributions of various wave components (second, third, and difference harmonics) to the formation of probability distributions of extreme wave heights, as well as the amplitudes of crests and troughs, are determined. The simulation results are analyzed taking into account four- and five-wave nonlinear interactions. Various nonlinear harmonics participate in the formation of probability distributions in a nontrivial way, which is essentially not amenable to the principles of linear addition and the contribution of ordering by a small nonlinearity parameter.
{"title":"Contributions of Nonlinear Spectral Components to the Probability Distribution of Rogue Waves Based on the Results of Numerical Simulation of the Euler Equations","authors":"A. V. Slunyaev","doi":"10.1134/s0001433823060105","DOIUrl":"https://doi.org/10.1134/s0001433823060105","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Based on the direct numerical modeling results of irregular nonlinear waves on the surface of deep water within the framework of three-dimensional potential equations of hydrodynamics, the contributions of various wave components (second, third, and difference harmonics) to the formation of probability distributions of extreme wave heights, as well as the amplitudes of crests and troughs, are determined. The simulation results are analyzed taking into account four- and five-wave nonlinear interactions. Various nonlinear harmonics participate in the formation of probability distributions in a nontrivial way, which is essentially not amenable to the principles of linear addition and the contribution of ordering by a small nonlinearity parameter.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":"65 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-25DOI: 10.1134/s0001433823330022
E. A. Malinovskaya, G. I. Gorchakov, A. V. Karpov, L. O. Maksimenkov, O. I. Datsenko
Abstract
The effect of the emergence of quasi-periodic oscillations of particle (with size >50 mсm) concentrations in the saltation flow has been detected in similar arid conditions in desertified areas: (1) using high-speed video in Astrakhan region (2009); (2) by acoustic method in the Republic of Kalmykia (2021). During the field experiments were revealed characteristic low frequencies (<50 Hz), which is associated with the peculiarities of the microrelief shape. More high frequences (>50 Hz) have been observed also. The appearance of these frequencies is determined by changes in the saltation cycle in heterogeneous topography. Such processes is simulated in a numerical experiment using the OpenFoam package. There are demonstrated the characteristic frequencies of changes in the number of particles (from 10 to 200 Hz) in the saltation flow over the surface ledge of the ripple type. Numerical experiments include analysis of frequency characteristics of particle concentration changes in the flow behind the ledge. Spectral analysis of data of numerical realizations of the saltation flow at variation of boundary parameters and height of the obstacle shows that the characteristic frequency or frequencies change and are close to those observed in the experiment. Input parameters such a models can be adjusted with such analysis.
{"title":"On the Conditions of the Emergence of a Periodic Mode of Saltating Flow","authors":"E. A. Malinovskaya, G. I. Gorchakov, A. V. Karpov, L. O. Maksimenkov, O. I. Datsenko","doi":"10.1134/s0001433823330022","DOIUrl":"https://doi.org/10.1134/s0001433823330022","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The effect of the emergence of quasi-periodic oscillations of particle (with size >50 mсm) concentrations in the saltation flow has been detected in similar arid conditions in desertified areas: (1) using high-speed video in Astrakhan region (2009); (2) by acoustic method in the Republic of Kalmykia (2021). During the field experiments were revealed characteristic low frequencies (<50 Hz), which is associated with the peculiarities of the microrelief shape. More high frequences (>50 Hz) have been observed also. The appearance of these frequencies is determined by changes in the saltation cycle in heterogeneous topography. Such processes is simulated in a numerical experiment using the OpenFoam package. There are demonstrated the characteristic frequencies of changes in the number of particles (from 10 to 200 Hz) in the saltation flow over the surface ledge of the ripple type. Numerical experiments include analysis of frequency characteristics of particle concentration changes in the flow behind the ledge. Spectral analysis of data of numerical realizations of the saltation flow at variation of boundary parameters and height of the obstacle shows that the characteristic frequency or frequencies change and are close to those observed in the experiment. Input parameters such a models can be adjusted with such analysis.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":"29 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-25DOI: 10.1134/s0001433823330010
I. P. Chunchuzov, O. M. Johannessen, O. E. Popov
Abstract
The structure and characteristics of the internal wave field (coherence, frequency spectra, phase velocities, dispersion of velocity fluctuations) observed in an ocean frontal zone on the shelf-slope east of the island of Malta is studied. Using spectral and coherence analysis of temporal temperature variations measured by two thermistor chains 7 km apart the near-inertial internal gravity waves (NIWs) were detected, and their wavelengths and trace velocities were estimated. The temperature, salinity and density front that existed during the measurement period and the bottom irregularities of island’s shelf are both proposed to be the sources of the observed NIWs and internal waves of different periods. The mechanism of formation of the frequency spectrum of the observed internal wave field is proposed. By analyzing the effect of advection of internal waves by an alternating current induced by all the internal waves the observed periodic change of the sign of the trace velocity of the internal waves is explained.
{"title":"Structure and Characteristics of Internal Wave Field in an Ocean Frontal Region East of Malta in Mediterranean","authors":"I. P. Chunchuzov, O. M. Johannessen, O. E. Popov","doi":"10.1134/s0001433823330010","DOIUrl":"https://doi.org/10.1134/s0001433823330010","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The structure and characteristics of the internal wave field (coherence, frequency spectra, phase velocities, dispersion of velocity fluctuations) observed in an ocean frontal zone on the shelf-slope east of the island of Malta is studied. Using spectral and coherence analysis of temporal temperature variations measured by two thermistor chains 7 km apart the near-inertial internal gravity waves (NIWs) were detected, and their wavelengths and trace velocities were estimated. The temperature, salinity and density front that existed during the measurement period and the bottom irregularities of island’s shelf are both proposed to be the sources of the observed NIWs and internal waves of different periods. The mechanism of formation of the frequency spectrum of the observed internal wave field is proposed. By analyzing the effect of advection of internal waves by an alternating current induced by all the internal waves the observed periodic change of the sign of the trace velocity of the internal waves is explained.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":"22 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-25DOI: 10.1134/s0001433823060063
M. V. Kalashnik
Abstract
The classical problem of geophysical hydrodynamics is the problem of instability of a zonal geostrophic flow with a vertical velocity shear. At present, the instability with respect to symmetric perturbations that do not depend on the coordinate along the flow has been most thoroughly studied. For a symmetric instability to arise, the two-dimensional perturbation wave vector must lie inside a certain sector in the vertical plane of the wave numbers. In this paper, we study the instability with respect to unsymmetric perturbations oriented at an angle to the flow. Fundamentally new features of the temporal dynamics of the amplitudes of such perturbations are found. The main feature is associated with the existence of a stage of exponential explosive growth of finite duration. A kinematic interpretation of this stage is given that is related to the passage of the projection of the three-dimensional wave vector onto the plane transversely to the flow through the sector of symmetric instability.
{"title":"Explosive Growth of Unsymmetric Perturbations in a Flow with a Vertical Shear","authors":"M. V. Kalashnik","doi":"10.1134/s0001433823060063","DOIUrl":"https://doi.org/10.1134/s0001433823060063","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The classical problem of geophysical hydrodynamics is the problem of instability of a zonal geostrophic flow with a vertical velocity shear. At present, the instability with respect to symmetric perturbations that do not depend on the coordinate along the flow has been most thoroughly studied. For a symmetric instability to arise, the two-dimensional perturbation wave vector must lie inside a certain sector in the vertical plane of the wave numbers. In this paper, we study the instability with respect to unsymmetric perturbations oriented at an angle to the flow. Fundamentally new features of the temporal dynamics of the amplitudes of such perturbations are found. The main feature is associated with the existence of a stage of exponential explosive growth of finite duration. A kinematic interpretation of this stage is given that is related to the passage of the projection of the three-dimensional wave vector onto the plane transversely to the flow through the sector of symmetric instability.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":"6 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-25DOI: 10.1134/s0001433823060026
B. A. Babanov, V. A. Semenov, I. I. Mokhov
Abstract
Various methods of cluster analysis are used for identifying large-scale atmospheric circulation regimes (weather regimes (WRs)). In this paper we compare the four most commonly used clustering methods: k-means (KM), Ward’s hierarchical clustering (HW), Gaussian mixture model (GM), and self-organizing maps (SOMs) to analyze WRs in the Euro-Atlantic (EAT) region. The data used for identifying WRs are 500 hPa geopotential height fields (z500) from the ERA5 reanalysis for 1940–2022. Four classical wintertime WRs are identified by the KM method—two regimes associated with positive and negative phases of the North Atlantic Oscillation (NAO+ and NAO–), a regime associated with the Scandinavian blocking (SB), and a regime characterized by elevated pressure over the Northern Atlantic. For summer months, the KM method gets WRs that are similar in spatial structure to the classical winter ones. The SOM method yields results that are almost identical to the results of the KM method. Unlike KM and SOM methods, HW and GM do not fully catch the spatial structure of all of the four classical winter EAT WRs and their summer analogues. Compared to WRs of the KM and SOM methods, WRs obtained by HW and GM methods explain less z500 variance; they have different occurrences, persistence, and transition features. Summer and winter WRs obtained by HW and GM methods are less similar to each other compared to WRs provided by the KM method. Average spatial correlation coefficients between mean z500 fields of WRs obtained by KM and HW methods are 0.76 in winter and 0.83 in summer; 0.70 in winter and 0.72 in summer for KM and GM methods; and 0.41 in winter and 0.44 in summer for the regimes compared between HW and GM methods, respectively. There are statistically significant trends of the seasonal occurrence of WRs found by some of the studied clustering methods—a positive trend for the occurrence of the NAO+ regime and a negative trend for the occurrence of the NAO-regime.
{"title":"Comparison of Cluster Analysis Methods for Identifying Weather Regimes in the Euro-Atlantic Region for Winter and Summer Seasons","authors":"B. A. Babanov, V. A. Semenov, I. I. Mokhov","doi":"10.1134/s0001433823060026","DOIUrl":"https://doi.org/10.1134/s0001433823060026","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Various methods of cluster analysis are used for identifying large-scale atmospheric circulation regimes (weather regimes (WRs)). In this paper we compare the four most commonly used clustering methods: k-means (KM), Ward’s hierarchical clustering (HW), Gaussian mixture model (GM), and self-organizing maps (SOMs) to analyze WRs in the Euro-Atlantic (EAT) region. The data used for identifying WRs are 500 hPa geopotential height fields (z500) from the ERA5 reanalysis for 1940–2022. Four classical wintertime WRs are identified by the KM method—two regimes associated with positive and negative phases of the North Atlantic Oscillation (NAO+ and NAO–), a regime associated with the Scandinavian blocking (SB), and a regime characterized by elevated pressure over the Northern Atlantic. For summer months, the KM method gets WRs that are similar in spatial structure to the classical winter ones. The SOM method yields results that are almost identical to the results of the KM method. Unlike KM and SOM methods, HW and GM do not fully catch the spatial structure of all of the four classical winter EAT WRs and their summer analogues. Compared to WRs of the KM and SOM methods, WRs obtained by HW and GM methods explain less z500 variance; they have different occurrences, persistence, and transition features. Summer and winter WRs obtained by HW and GM methods are less similar to each other compared to WRs provided by the KM method. Average spatial correlation coefficients between mean z500 fields of WRs obtained by KM and HW methods are 0.76 in winter and 0.83 in summer; 0.70 in winter and 0.72 in summer for KM and GM methods; and 0.41 in winter and 0.44 in summer for the regimes compared between HW and GM methods, respectively. There are statistically significant trends of the seasonal occurrence of WRs found by some of the studied clustering methods—a positive trend for the occurrence of the NAO+ regime and a negative trend for the occurrence of the NAO-regime.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-25DOI: 10.1134/s0001433823060087
S. A. Riabova, S. L. Shalimov
Abstract
The variations of the ionospheric current in the lower ionosphere and the plasma density of the upper ionosphere have been studied based on the monitoring of the horizontal component of the geomagnetic field induction and height-frequency sounding of the critical frequency of the ionosphere F layer at the Moscow Observatory. It is shown that, in the spectra of time variations of the geomagnetic field and the critical frequency of the F2 layer in the range of planetary waves in winter, there are both harmonics associated with solar activity and harmonics corresponding to quasi-5-, 10-, and 16-day planetary waves. The involvement of geomagnetic field registration data for a 20-year time interval (from 2001 to 2020) have made it possible to identify more subtle effects, namely, the harmonics associated with the modulation effect of longer period variations and tidal effects are identified.
{"title":"Atmospheric Planetary Waves at Ionospheric Heights Measured at the Moscow Observatory (IZMIRAN)","authors":"S. A. Riabova, S. L. Shalimov","doi":"10.1134/s0001433823060087","DOIUrl":"https://doi.org/10.1134/s0001433823060087","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The variations of the ionospheric current in the lower ionosphere and the plasma density of the upper ionosphere have been studied based on the monitoring of the horizontal component of the geomagnetic field induction and height-frequency sounding of the critical frequency of the ionosphere F layer at the Moscow Observatory. It is shown that, in the spectra of time variations of the geomagnetic field and the critical frequency of the F2 layer in the range of planetary waves in winter, there are both harmonics associated with solar activity and harmonics corresponding to quasi-5-, 10-, and 16-day planetary waves. The involvement of geomagnetic field registration data for a 20-year time interval (from 2001 to 2020) have made it possible to identify more subtle effects, namely, the harmonics associated with the modulation effect of longer period variations and tidal effects are identified.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":"71 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-25DOI: 10.1134/s0001433823060051
D. P. Gubanova, A. A. Vinogradova, E. A. Lezina, M. A. Iordanskii, A. A. Isakov
Abstract
Data from continuous observations of aerosol composition in the surface atmosphere in Moscow (in the city center) and in Moscow oblast (near the city of Zvenigorod) for three years, from the fall of 2019 to the end of 2022, are analyzed. The data were compared with the results of observations at the Moscow network of stations of the State Budgetary Institution Mosecomonitoring. The concept of conditional background aerosol pollution of the near-surface atmosphere in Moscow has been introduced for those days when the daily mean mass concentration of PM10 particles was below the maximum permissible concentration (MPC) (60 μg/m3). The number of such days exceeded 91% in Moscow over three years of observations. Previously, the authors found that all episodes of higher aerosol pollution of urban air (exceeding the MPC) are associated either with the presence of a close local source in the city or with the long-distance transport of combustion aerosols and/or dust to Moscow and its suburbs from other regions. The daily mean concentration of PM2.5 in the city and the suburb is year-round below the MPC (35 μg/m3). The conditional background aerosol pollution of the surface atmosphere is formed by both natural and anthropogenic sources of aerosols, not only of local, but also of remote origin. Its level and composition implicitly reflect the influence of meteorological parameters on the sources and sinks of aerosols and also the influence of advective transport of aerosol by air masses to and from the city. The results of analysis of seasonal variations in various indicators of aerosol composition in the surface atmosphere under conditional background pollution are presented: the mass concentration of PM10 and PM2.5 particles and individual chemical elements and the distribution of chemical elements by size of aerosol particles. Similarities and differences between these characteristics in the surface air of the city and the suburb in different seasons are specially emphasized.
{"title":"Conditional Background Level of Aerosol Pollution in Surface Air in Moscow and One of its Suburbs: Seasonal Variations","authors":"D. P. Gubanova, A. A. Vinogradova, E. A. Lezina, M. A. Iordanskii, A. A. Isakov","doi":"10.1134/s0001433823060051","DOIUrl":"https://doi.org/10.1134/s0001433823060051","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Data from continuous observations of aerosol composition in the surface atmosphere in Moscow (in the city center) and in Moscow oblast (near the city of Zvenigorod) for three years, from the fall of 2019 to the end of 2022, are analyzed. The data were compared with the results of observations at the Moscow network of stations of the State Budgetary Institution Mosecomonitoring. The concept of conditional background aerosol pollution of the near-surface atmosphere in Moscow has been introduced for those days when the daily mean mass concentration of PM<sub>10</sub> particles was below the maximum permissible concentration (MPC) (60 μg/m<sup>3</sup>). The number of such days exceeded 91% in Moscow over three years of observations. Previously, the authors found that all episodes of higher aerosol pollution of urban air (exceeding the MPC) are associated either with the presence of a close local source in the city or with the long-distance transport of combustion aerosols and/or dust to Moscow and its suburbs from other regions. The daily mean concentration of PM<sub>2.5</sub> in the city and the suburb is year-round below the MPC (35 μg/m<sup>3</sup>). The conditional background aerosol pollution of the surface atmosphere is formed by both natural and anthropogenic sources of aerosols, not only of local, but also of remote origin. Its level and composition implicitly reflect the influence of meteorological parameters on the sources and sinks of aerosols and also the influence of advective transport of aerosol by air masses to and from the city. The results of analysis of seasonal variations in various indicators of aerosol composition in the surface atmosphere under conditional background pollution are presented: the mass concentration of PM<sub>10</sub> and PM<sub>2.5</sub> particles and individual chemical elements and the distribution of chemical elements by size of aerosol particles. Similarities and differences between these characteristics in the surface air of the city and the suburb in different seasons are specially emphasized.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":"10 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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