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Due to the increase in radon emanation, the conductivity in the surface layer of air increases, which causes variations in the electric fields in the low atmosphere and according to some hypotheses in the ionosphere. There are well-known proposals on the possibility of using such ionospheric disturbances as precursors of earthquakes. In this study, the ionospheric electric fields are calculated in the framework of a quasi-stationary model of the conductor consisting of the atmosphere, including the ionosphere. The consequences of the paradoxical point of view on the decrease in the conductivity of surface air with an increase in radon content are also considered. It is shown that even with extreme radon emanation, the obtained calculated perturbations of the ionospheric electric field are three to four orders of magnitude smaller than the supposed precursors of earthquakes. [ABSTRACT FROM AUTHOR]

To assess the relative contribution of key chemical and physical processes to the observed variability in climate and atmospheric gas composition from the 1980s to the 2020s, numerical experiments were conducted using the chemical-climatic model SOCOLv3. The study investigated factors determining the variability of principal climatic characteristics, including changes in the concentrations of ozone-depleting substances; variations in greenhouse gas concentrations, sea surface temperature, and sea ice extent; fluctuations in solar activity; and alterations in atmospheric aerosol content. Calculations for scenarios considering each of these factors individually, as well as a baseline model experiment accounting for all factors concurrently, were performed to evaluate the relative roles of these factors. The outcomes of the numerical experiments determined the relative contributions of different factors to changes in tropospheric temperature, lower stratospheric temperature, and ozone content from 1980 to 2020. The results of the model calculations were then compared with data from SBUV satellite measurements. [ABSTRACT FROM AUTHOR]

We present the most significant results of Russian scientists in the field of atmospheric ozone research for 2019–2022 and examine observations of tropospheric ozone, its distribution and variability on the territory of the Russian Federation, its relation with atmospheric parameters, modeling of formation processes, and its impact on public health. The state of stratospheric ozone over Russia, modeling of processes in the ozonosphere, and methods and instruments being developed are also analyzed. The review is a part of Russia's national report on meteorology and atmospheric sciences, which was prepared for the International Association of Meteorology and Atmospheric Sciences (IAMAS). It has been reviewed and approved at the 28th General Assembly of the International Union of Geodesy and Geophysics (IUGG). [ABSTRACT FROM AUTHOR]

Protolytic equilibrium constants in an aqueous solution of pyridoxal-5'-phosphate hydrazone and L-tyrosine are determined spectrophotometrically at 25.0 ± 0.1°C and near-zero ionic strength. The obtained constants agree with the literature data for similar compounds. [ABSTRACT FROM AUTHOR]

The contribution of Igor' Leonidovich Karol' to world and national science is described. Three stages of his scientific research are identified: (1) modeling of the dynamics of the atmosphere, (2) modeling of chemical and radiation processes in the atmosphere, and (3) modeling of modern climate changes. Attention is paid to the pedagogical work of Karol' and his contribution to the popularization of science. [ABSTRACT FROM AUTHOR]

This paper presents the results of model calculations of the behavior of the ionosphere during a complex space-weather event that occurred in September 2017. The main attention is paid to the analysis of the response of an integral characteristic of the ionosphere—global electron content (GEC)—to geomagnetic storms on September 7–8. Comparison of the temporal behavior of the model and experimental GEC showed there to be a good qualitative agreement between the temporal variations of hydroelectric power stations associated with geomagnetic storms. At the same time, the absence in the results of model calculations of positive hydroelectric disturbances observed on September 7, 8, and 11 is noted. It is hypothesized that these positive disturbances of the GEC on the indicated days may be associated with the observed solar-proton events and precipitation of protons from the magnetosphere, but not taken into account in model calculations. [ABSTRACT FROM AUTHOR]

Results are presented from an analysis of data on the precipitation of high-energy magnetospheric electrons into the atmosphere and their impact on the concentration of nitrogen oxide NO in the atmosphere at altitudes of 64–90 km. Series of data on precipitation recorded on balloons at the Apatity polar station (Murmansk region) in the period 2002–2012 and results from NO measurements with the SCIAMACHY spectrometer installed onboard the European ENVISAT satellite are used. The response of variations in the concentration of nitrogen oxides to individual events of the precipitation of high-energy electrons and the average response to all events recorded in the atmosphere in 2002–2012 are considered. [ABSTRACT FROM AUTHOR]

The results of the study of the variability of the electron concentration in the ionosphere in January 2009 are presented. Variations in the electron density in the ionosphere above individual stations and in the global electron content are considered based on the observation data and the results of the model calculations. Comparison of the ionospheric variability obtained from the results of calculations using the models of the upper atmosphere (GSM TIP) and the entire atmosphere (EAGLE) showed that the atmospheric-ionospheric interaction can play one of the key roles in the variability of the ionosphere at midlatitudes. The paper also discusses the issue of simulating the effects of stratospheric warming in 2009 using the EAGLE model. [ABSTRACT FROM AUTHOR]

Atmospheric electric fields (AEFs) are produced by both natural processes and electrical infrastructure and are increasingly recognized to influence and interfere with various organisms and biological processes, including human well-being. Atmospheric electric fields, in particular electromagnetic fields (EMFs), currently attract a lot of scientific attention due to emerging technologies such as 5G and satellite internet. However, a broader retrospective analysis of available data for both natural and artificial AEFs and EMFs is hampered due to a lack of a semantic approach, preventing data sharing and advancing our understanding of its intrinsic links. Therefore, here we create an ontology (ENET_Ont) for existing (big) data on AEFs within the context of biological systems that is derived from different disciplines that are distributed over many databases. Establishing an environment for data sharing provided by the proposed ontology approach will increase the value of existing data and facilitate reusability for other communities, especially those focusing on public health, ecology, environmental health, biology, climatology as well as bioinformatics. [ABSTRACT FROM AUTHOR]

This article presents the main stages of the development of a new model, the entire atmosphere (EAGLE). We describe the models of the lower,middle, and upper atmospheres that constitute EAGLE and present the way we coupled. The results of the EAGLE model confirm that the four-peak longitude variation and the evening surge of the eastern electric field at the equator are consequences of the atmosphere–ionosphere interaction. This result illustrates that the EAGLE model is an useful tool for studying the influence of the atmosphere on the electric field in the equatorial ionosphere. [ABSTRACT FROM AUTHOR]

The results of analyzing the planetary and tidal variabilities in the mesosphere, thermosphere, and ionosphere acquired in calculations for January 2009 using two versions of the EAGLE model are presented. It is shown that, during a sudden stratospheric warming (SSW), the planetary and tidal-wave activity increases in the lower thermosphere. The features of the changes in solar-migrating and nonmigrating components of tidal variabilities in the parameters of the thermosphere, ionosphere, and electric fields are considered. The reproduction of the vertical electromagnetic drift during the SSW period over the Jicamarca station is explained by a significant increase in the diurnal and semidiurnal tidal variability. [ABSTRACT FROM AUTHOR]

Results are presented from molecular dynamics modeling of the crystallization of a supercooled Lennard-Jones liquid. Calculations are made for three isobars at positive and negative pressures. The height of the crystallization activation barrier is determined via metadynamics, and the size dependence is calculated for the effective surface free energy at the liquid–critical crystal nucleus interface. [ABSTRACT FROM AUTHOR]

The paper presents the results of modeling ionospheric parameters using the Global Self-Consistent Model of the Thermosphere, Ionosphere, and Protonosphere (GSM TIP) of the Earth. Numerical experiments have been performed for three variants of the solar EUV spectrum data: the Nusinov model, EUVAC, and generalized solar flux measurements (SOLID). The calculations have been carried out on March 22, 2009 (F10.7 ~ 68) and March 22, 2014 (F10.7 ~ 154). The maximum ionization rate and, correspondingly, the critical frequency of the F2 layer have been obtained using the Nusinov model for low and high solar activities. The lowest ionization rates and values of foF2 have been obtained using the EUVAC model. Simulations with the SOLID spectrum show the better agreement of foF2 with the empirical model IRI-2007 at the maximum solar activity. At the same time, at the minimum solar activity, all models of the spectrum provide an underestimation of the values of the critical frequency of the F2 layer. [ABSTRACT FROM AUTHOR]

The mechanisms of the influence of various energetic particles on the atmosphere and their consideration by modern models are discussed. The types of energetic particles considered are galactic cosmic rays, auroral electrons, solar protons, and electrons precipitating into the atmosphere from outer radiation belt. The effects of these particles on the ozone layer and climate are illustrated using observational data and model calculations. The influence of galactic cosmic rays is noticeable only in the troposphere at southern latitudes, whereas a strong but short-term destruction of ozone by episodic solar protons have no effect at climatic time scales. Thus, the main influence on the long-term ozone layer variability is exerted by energetic electrons. Changing ozone contents lead to changing heating rates, temperature, and structure of stratospheric circulation, which in turn affects wave processes and climate. Simulation of these processes requires the use of complex numerical models that include all necessary processes and their interaction in the atmosphere from the surface to the upper thermosphere. [ABSTRACT FROM AUTHOR]

In this paper, we discuss perturbations in neutral temperature, total electron content (TEC), and critical frequency of the maximum of the F2 layer (foF2) during the sudden stratospheric warming in January 2009. The calculations were performed using the first version of the EAGLE (Entire Atmosphere Global Model), which is a combination of the models of the low-middle atmosphere (HAMMONIA) and the upper atmosphere (GSM TIP). The EAGLE reproduces observed stratospheric warming and related mesospheric cooling in the northern polar cap in January 2009. At thermospheric altitudes, the neutral temperature perturbations have a quasi-wave character with a wavelength of ∼40 km in the vertical direction. Our results indicate that the HAMMONIA model should be used in the EAGLE instead of the GSM TIP model for the neutral temperature calculations in the altitude region from 80 to 120 km. It is shown that the obtained model foF2 and TEC perturbations are mainly related to seasonal variations. The most-pronounced perturbations in the ionospheric electron density due to stratospheric warming are formed near the equator and are basically negative. Our analysis of the neutral temperature and electron density perturbations made it possible to conclude that the dependence of ionospheric parameters on seasonal changes in solar zenith angle is stronger than for the thermosphere parameters. [ABSTRACT FROM AUTHOR]

Sudden stratospheric warming (SSW) is a unique atmospheric phenomenon, which consists in a rapid rise of temperature at altitudes of ~30-40 km in high latitudes of the winter, typically, northern hemisphere. Modeling SSW effects in the mesosphere, thermosphere, and ionosphere is a challenging problem, because it must be done on a global scale, with consideration of numerous physical and chemical processes. This paper reports the results of calculations of the characteristics of total electron content (TEC) perturbations for the conditions of the SSW event in January 2009. The calculations are performed using the Global Self-Consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP) supplemented by the lower boundary conditions in the form of space-time distributions of the basic parameters of the mesosphere at an altitude of 80 km, as calculated by the SOCOL, KASIMA, and TIME GCM models. The simulation results show that, for some versions, the spatial distribution of total electron content disturbances ΔTEC shows a qualitative agreement with experimental data; however, the values of ΔTEC in all variants of calculations proved to be an order of magnitude lower than the measured. [ABSTRACT FROM AUTHOR]

We analyze the variability of the spectral solar irradiance during the period from 7 January 2010 until 20 January 2010 as measured by the Herzberg channel (190 - 222 nm) of the Large Yield RAdiometer (LYRA) onboard PROBA2. In this period of time, observations by the LYRA nominal unit experienced degradation and the signal produced by the Herzberg channel frequently jumped from one level to another. Both factors significantly complicate the analysis. We present the algorithm that allowed us to extract the solar variability from the LYRA data and compare the results with SORCE/SOLSTICE measurements and with modeling based on the Code for the Solar Irradiance (COSI). [ABSTRACT FROM AUTHOR]

We evaluate the influence of the galactic cosmic rays (GCR), solar proton events (SPE), and energetic electron precipitation (EEP) on chemical composition of the atmosphere, dynamics, and climate using the chemistry-climate model SOCOL. We have carried out two 46-year long runs. The reference run is driven by a widely employed forcing set and, for the experiment run, we have included additional sources of NO and HO caused by all considered energetic particles. The results show that the effects of the GCR, SPE, and EEP fluxes on the chemical composition are most pronounced in the polar mesosphere and upper stratosphere; however, they are also detectable and statistically significant in the lower atmosphere consisting of an ozone increase up to 3 % in the troposphere and ozone depletion up to 8 % in the middle stratosphere. The thermal effect of the ozone depletion in the stratosphere propagates down, leading to a warming by up to 1 K averaged over 46 years over Europe during the winter season. Our results suggest that the energetic particles are able to affect atmospheric chemical composition, dynamics, and climate. [ABSTRACT FROM AUTHOR]

The solar climate ozone links (SOCOL) three-dimensional chemistry-climate model is used to estimate changes in the ozone and atmospheric dynamics over the 21st century. With this model, four numerical time-slice experiments were conducted for 1980, 2000, 2050, and 2100 conditions. Boundary conditions for sea-surface temperatures, sea-ice parameters, and concentrations of greenhouse and ozone-depleting gases were set following the IPCC A1B scenario and the WMO A1 scenario. From the model results, a statistically significant cooling of the model stratosphere was obtained to be 4-5 K for 2000-2050 and 3-5 K for 2050-2100. The temperature of the lower atmosphere increases by 2-3 K over the 21st century. Tropospheric heating significantly enhances the activity of planetary-scale waves at the tropopause. As a result, the Eliassen-Palm flux divergence considerable increases in the middle and upper stratosphere. The intensity of zonal circulation decreases and the meridional residual circulation increases, especially in the winter-spring period of each hemisphere. These dynamic changes, along with a decrease in the concentrations of ozone-depleting gases, result in a faster growth of O outside the tropics. For example, by 2050, the total ozone in the middle and high latitudes approaches its model level of 1980 and the ozone hole in Antarctica fills up. The superrecovery of the model ozone layer in the middle and high latitudes of both hemispheres occurs in 2100. The tropical ozone layer recovers far less slowly, reaching a 1980 level only by 2100. [ABSTRACT FROM AUTHOR]

A multi-model set of atmospheric simulations forced by historical sea surface temperature (SST) or SSTs plus Greenhouse gases and aerosol forcing agents for the period of 1950–1999 is studied to identify and understand which components of the Asian–Australian monsoon (A–AM) variability are forced and reproducible. The analysis focuses on the summertime monsoon circulations, comparing model results against the observations. The priority of different components of the A–AM circulations in terms of reproducibility is evaluated. Among the subsystems of the wide A–AM, the South Asian monsoon and the Australian monsoon circulations are better reproduced than the others, indicating they are forced and well modeled. The primary driving mechanism comes from the tropical Pacific. The western North Pacific monsoon circulation is also forced and well modeled except with a slightly lower reproducibility due to its delayed response to the eastern tropical Pacific forcing. The simultaneous driving comes from the western Pacific surrounding the maritime continent region. The Indian monsoon circulation has a moderate reproducibility, partly due to its weakened connection to June–July–August SSTs in the equatorial eastern Pacific in recent decades. Among the A–AM subsystems, the East Asian summer monsoon has the lowest reproducibility and is poorly modeled. This is mainly due to the failure of specifying historical SST in capturing the zonal land-sea thermal contrast change across the East Asia. The prescribed tropical Indian Ocean SST changes partly reproduce the meridional wind change over East Asia in several models. For all the A–AM subsystem circulation indices, generally the MME is always the best except for the Indian monsoon and East Asian monsoon circulation indices. [ABSTRACT FROM AUTHOR]

A one-dimensional ionic-photochemical model of the gaseous composition of the atmosphere that describes the formation of the D layer of the ionosphere is presented. Based on this model, the vertical profiles of the concentration of electrons and ions in the D layer of the ionosphere were calculated, as were the vertical distributions of minor gaseous constituents in the atmosphere up to a height of 86 km for undisturbed conditions and after a powerful solar proton events (SPE) at the end of October 2003. The calculations showed that SPEs significantly increase NOx in the mesosphere of polar latitudes. In the lower mesosphere of polar caps, the NOx mixing ratio increases by 20–50 ppb; in the upper mesosphere it increases by 100 ppb and more. High NOx levels in zones of their formation can be retained for several weeks, producing a long-term but comparatively small ozone decrease in the lower mesosphere. The main ozone decrease is caused by a short-term HOx increase after SPEs and is also of a short-term character in the conditions of the illuminated mesosphere. After the SPE in October 2003, model calculations yield an ozone concentration decrease by 40% in the middle and upper mesosphere at 75 ° S and by 70% at the same heights at 70 ° N. The results of modeling NOx and O3 changes after the SPE in October 2003 agree well with the data of satellite measurements. The changes in minor gases of the mesosphere after the SPE obtained in the model with parameterized sources of HOx and NOx are compared with their changes obtained in the complete ionic-photochemical model. The changes in HOx, NOx, and O3 coincide rather well, whereas the changes in ClO noticeably differ, especially in the lower mesosphere. Thus, at a height of about 60 km, the parameterized photochemical model underestimated twofold the ClO formation after the SPE. [ABSTRACT FROM AUTHOR]

The ability of atmospheric general circulation models (AGCMs), that are forced with observed sea surface temperatures (SSTs), to simulate the Indian monsoon rainfall (IMR) variability on interannual to decadal timescales is analyzed in a multimodel intercomparison. The multimodel ensemble has been performed within the CLIVAR International “Climate of the 20th Century” (C20C) Project. This paper is part of a C20C intercomparison of key climate time series. Whereas on the interannual timescale there is modest skill in reproducing the observed IMR variability, on decadal timescale the skill is much larger. It is shown that the decadal IMR variability is largely forced, most likely by tropical sea surface temperatures (SSTs), but as well by extratropical and especially Atlantic Multidecadal Oscillation (AMO) related SSTs. In particular there has been a decrease from the late 1950s to the 1990s that corresponds to a general warming of tropical SSTs. Using a selection of control integrations from the World Climate Research Programme’s (WCRP’s) Coupled Model Intercomparison Project phase 3 (CMIP3), it is shown that the increase of greenhouse gases (GHG) in the twentieth century has not significantly contributed to the observed decadal IMR variability. [ABSTRACT FROM AUTHOR]

The West Siberian region is one of the main contributors of the atmospheric greenhouse gas methane due to the large areas of wetlands, rivers, lakes and numerous gas deposits situated there. But there are no reliable estimations of integral methane flux from this area into the atmosphere. For assessment of methane fluxes in West Siberia the specially constructed 3-D regional chemical transport model was applied. The 3-D distribution of methane is calculated on the basis of the current meteorological data fields (wind, temperature, geopotential) updated 4 times a day. The methane concentrations measured near the main gas fields of West Siberia in the summer season of 1999, were used for correction of methane flux intensity estimates obtained previously by comparison of measurements carried out in summer 1993 and 1996 with modelled methane mixing ratio distribution. This set of field and model experiments confirmed the preliminary conclusion about low leakage intensity: anthropogenic methane flux does not exceed 5–15% of total summer methane flux, estimated as 11–12 Mt CH4 in summer from this region, in spite of the large areas of gas deposits located there. [ABSTRACT FROM AUTHOR]

The author's name should read H. Schmidt instead of Kh. Shmidt [ABSTRACT FROM AUTHOR]