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In this paper, a detailed analysis of the distribution of intensity of vortex circular airy beam (CAB) propagating in a turbulent atmosphere applying Fresnel–Kirchhoff diffraction integral equations is presented. A turbulent atmosphere consists of different types of aberrations. The existence of aberrations in an atmosphere under turbulence plays a vital part in affecting the quality of optical beams. Here, the effect of different aberrations such as z-tilt, defocus, astigmatism, coma, and spherical aberration on the intensity distribution and structure of vortex CAB at two different propagation distances under four different atmospheric turbulent conditions with topological charge m = 1 were investigated. The two different propagation distances which we have used in this scenario are z = 2000 m and z = 5000 m. A numerical analysis was performed for each aberration, and corresponding 3d and 2d plots were plotted. The results show that spherical aberration has the highest effect than the other four aberrations on the intensity distribution of vortex CAB and z-tilt aberration has the least effect. Also, the analysis shows that the quality of the beam reduces with an increase in propagation distance. A comparison study was also done to identify the difference between vortex CAB and non-vortex CAB. Based on the comparison results, it is revealed that the maximum intensity distribution and quality of beam could be achieved more with vortex CAB than with non-vortex CAB. [ABSTRACT FROM AUTHOR]

The paper provides a joint analysis of Aqua/MODIS data, global ocean reanalysis GLORYS12V1, and atmospheric reanalysis ERA5. We consider the quasi-permanent Lofoten Vortex located in the Norwegian Sea. Analysis of SST maps reveals the existence of a cold spot in the area of the Lofoten Vortex in the summer–autumn period. A joint analysis of satellite maps and GLORYS12V1 data shows that the main reason for the formation of the cold spot is the rise of the isopicns of the upper dome of the vortex and the destruction of the heated layer, as a result of which colder isopicns come to the surface. It is revealed that in many cases the cold spot shifts to the periphery of the vortex in a southeasterly direction, and the shift can be several tens of kilometers. The reason may be the vortex advection of particles in an anticyclonic vortex. It is shown that along with the formation of the cold spot, there is a 10–30 m decrease in the depth of the upper quasi-homogeneous layer above the Lofoten Vortex in the summer–autumn period. The formation of a cold spot on the water surface is accompanied by a decrease in temperature in the drive layers of the atmosphere. [ABSTRACT FROM AUTHOR]

This paper considers reconstructions of the heliospheric modulation potential, which characterizes solar activity variations, over the past 20 000 years on the basis of radiocarbon data. This time interval includes the period of climate transition from the Last Ice Age to the Holocene and the Holocene itself. The reconstruction process takes into account variations in the global temperature and carbon dioxide content in the Earth's atmosphere. The variation in the rate of radiocarbon transfer from the ocean to the atmosphere and from the atmosphere to the biosphere is also taken into account. In particular, it is shown that high solar activity in the 13th millennium BC could cause the Meiendorf warming, and a decrease in solar activity could lead to a decrease in the global temperature in the period starting from 3000 BC. [ABSTRACT FROM AUTHOR]

Observations of vibrationally excited hydroxyl (OH*) emissions are widely used to obtain information on atmospheric dynamics and composition. In this paper, several analytical approximations are presented for characteristics of the hydroxyl layer in the Martian atmosphere, such as OH* concentrations at the maximum and the height of the maximum. Relationships are also given for estimating the influence of various factors on the OH* layer in nighttime conditions. These characteristics are determined by the ambient temperature and the concentration of atomic oxygen, including their vertical gradients. The obtained relationships are applied to the results of numerical modeling using the global atmospheric circulation model to predict the seasonal behavior of the hydroxyl layer on Mars. Based on the modeling data, the annual and intra-annual variations in the concentration of excited hydroxyl and the height of the OH* layer on Mars show both similarities to and considerable differences from those on Earth. The concentration and the height of the maximum in the equatorial, northern, and southern middle latitudes vary with the season, with the maximum concentrations and the lowest height being recorded in the first half of the year. Model calculations confirmed the presence of a peak in the OH* concentration in polar latitudes in winter at a height of approximately 50 km with volume emission densities of 2.1, 1.4, and 0.6 × 104 photons cm–3 s–1 for the transitions of vibrational levels 1–0, 2–1, and 2– 0, respectively. The resulting relationships can be used to analyze measurements and interpret their variations. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are emitted to the atmosphere by various anthropogenic activities as well as natural sources, they undergo long-range transport, are degraded (e.g., by photolysis) and finally they are deposited onto the surface and potentially accumulate in topsoil. The dry deposition of particle-bound PAHs dominates the accumulation of PAHs in soil and their further fate in soil is governed by sorption/desorption from these airborne particles. This paper offers an overview on concentrations of particle-bound PAHs, the dry deposition fluxes and finally concentrations of PAHs in soil. In addition, spatial and temporal variations of PAHs are considered. The results show that concentrations of particle-bound PAHs typically range from 1 mg g−1 up to 10 mg g−1 in cities with coal-based heating in winter and in countries with coal-based industry incl. electrical power production. These values are very high and exceed the legal limits set in soils by orders of magnitude. Atmospheric deposition rates typically reach several mg m−2 a−1, but in winter, especially in countries with heating, deposition rates are up to 10 times higher. PAHs concentrations in soils show a very wide variation from less than 1 µg g−1 in rural areas up to 10 µg g−1 in urban space, which is about 1000 times lower than the concentration of PAHs on particles in the atmosphere. This demonstrates the relevance of high concentrations of PAHs on airborne particles deposited on soils, which also highlights the importance of considering incremental lifetime cancer risk models for both air and soil and assessing the total health risk of PAHs to humans. [ABSTRACT FROM AUTHOR]

The paper studies the temperature conditions under which the emergence and self-development of vortex motion in the real atmosphere are possible. [ABSTRACT FROM AUTHOR]

In this paper, the paraxial propagation of a partially coherent vortex cosine-hyperbolic-Gaussian beam (PCvChGB) in a turbulent atmosphere is investigated theoretically. The analytical expression of the average intensity for a PCvChGB propagating in a turbulent atmosphere is derived based on the Huygens–Fresnel integral and Rytov method. Numerical examples illustrating the effects of turbulence on beam propagation under various initial beam parameters and coherence length are presented. It is found that a PCvChGB spreads faster when the coherence length σ is smaller. The beam can keep its initial hollow dark profile unchanged within a short propagation range, and then is transformed into a solid Gaussian-like beam in the far field. The beam conversion speed is faster at stronger turbulence, larger vortex charge M and smaller decentered b, initial coherence length or wavelength. The obtained results could be beneficial for applications of PCvChGB in optical communications, remote sensing, and atom optics. [ABSTRACT FROM AUTHOR]

The conditional nonlinear optimal perturbation (CNOP for short) approach is a powerful tool for predictability and targeted observation studies in atmosphere-ocean sciences. By fully considering nonlinearity under appropriate physical constraints, the CNOP approach can reveal the optimal perturbations of initial conditions, boundary conditions, model parameters, and model tendencies that cause the largest simulation or prediction uncertainties. This paper reviews the progress of applying the CNOP approach to atmosphere-ocean sciences during the past five years. Following an introduction of the CNOP approach, the algorithm developments for solving the CNOP are discussed. Then, recent CNOP applications, including predictability studies of some high-impact ocean-atmospheric environmental events, ensemble forecast, parameter sensitivity analysis, uncertainty estimation caused by errors of model tendency or boundary condition, are reviewed. Finally, a summary and discussion on future applications and challenges of the CNOP approach are presented. [ABSTRACT FROM AUTHOR]

Proper modeling of seasonal signals and their quantitative analysis are of interest in geoscience applications, which are based on position time series of permanent GPS stations. Seasonal signals in GPS short-baseline (< 2 km) time series, if they exist, are mainly related to site-specific effects, such as thermal expansion of the monument (TEM). However, only part of the seasonal signal can be explained by known factors due to the limited data span, the GPS processing strategy and/or the adoption of an imperfect TEM model. In this paper, to better understand the seasonal signal in GPS short-baseline time series, we adopted and processed six different short-baselines with data span that varies from 2 to 14 years and baseline length that varies from 6 to 1100 m. To avoid seasonal signals that are overwhelmed by noise, each of the station pairs is chosen with significant differences in their height (> 5 m) or type of the monument. For comparison, we also processed an approximately zero baseline with a distance of < 1 m and identical monuments. The daily solutions show that there are apparent annual signals with annual amplitude of ~ 1 mm (maximum amplitude of 1.86 ± 0.17 mm) on almost all of the components, which are consistent with the results from previous studies. Semi-annual signal with a maximum amplitude of 0.97 ± 0.25 mm is also present. The analysis of time-correlated noise indicates that instead of flicker (FL) or random walk (RW) noise, band-pass-filtered (BP) noise is valid for approximately 40% of the baseline components, and another 20% of the components can be best modeled by a combination of the first-order Gauss-Markov (FOGM) process plus white noise (WN). The TEM displacements are then modeled by considering the monument height of the building structure beneath the GPS antenna. The median contributions of TEM to the annual amplitude in the vertical direction are 84% and 46% with and without additional parts of the monument, respectively. Obvious annual signals with amplitude > 0.4 mm in the horizontal direction are observed in five short-baselines, and the amplitudes exceed 1 mm in four of them. These horizontal seasonal signals are likely related to the propagation of daily/sub-daily TEM displacement or other signals related to the site environment. Mismodeling of the tropospheric delay may also introduce spurious seasonal signals with annual amplitudes of ~ 5 and ~ 2 mm, respectively, for two short-baselines with elevation differences greater than 100 m. The results suggest that the monument height of the additional part of a typical GPS station should be considered when estimating the TEM displacement and that the tropospheric delay should be modeled cautiously, especially with station pairs with apparent elevation differences. The scheme adopted in this paper is expected to explicate more seasonal signals in GPS coordinate time series, particularly in the vertical direction. [ABSTRACT FROM AUTHOR]

Over the last decade, a number of papers discussing long-period sunspot oscillations—with periods of tens and hundreds of minutes—have appeared. These studies are mainly based on the data of space probes. Despite the many possibilities in the time resolution and the absence of a distorting effect of the atmosphere, such studies face some artifacts connected with the pixel structure of an image (Nagovitsyn and Rybak, 2014); the existence of this phenomenon itself is still under discussion. On the other hand, starting already in the 1970s, long-period oscillations were studied by groundbased methods, including optical investigations after the mid-1980s. Since the papers containing the results of this research were mainly published in the Russian literature, which is not readily available for a wide range of specialists (mostly, in the Solnechnye Dannye bulletin or the proceedings of all-Russia conferences), they have been lost. The objective of this review is to recall these studies and their results and to combine the earlier findings with up-to-date ones. [ABSTRACT FROM AUTHOR]

The paper discusses the use of measurements of the IKFS-2 hyperspectral infrared sounder installed on Meteor-M polar-orbiting weather satellites for remote derivation of the atmospheric parameters related to so called essential climate variables (ECV) of the atmosphere, whose monitoring is necessary to characterize the climate system and its changes. The ECVs include the concentrations of the main atmosphere greenhouse gases (water vapor, carbon dioxide, methane, and ozone), characteristics of clouds and aerosols, as well as vertical temperature profiles, near-surface temperature, etc. A brief description of the IKFS-2 instrument and the results of its operation on board the Meteor-M spacecraft No. 2 during the period from the autumn of 2014 till now is given. The possibility of forming multiyear homogeneous series containing IKFS-2 measurements and satellite-based estimates of the aforementioned atmospheric ECVs is analyzed. An advanced method for deriving the total content of atmospheric carbon dioxide from IKFS-2 measurements is presented. The information on the errors of satellite-based ECV estimates obtained from their comparison with independent observations is provided. [ABSTRACT FROM AUTHOR]

We describe a collaborative analysis study involving numerical models and observation data for the Tokyo metropolitan area called the ULTra-sIte for Measuring Atmosphere of Tokyo Metropolitan Environment (ULTIMATE) project. It evaluates cloud microphysics schemes of numerical models using extensive observation data for the Tokyo area. We have access to various remote sensing and in situ data for the Tokyo area for operational and research purposes, particularly by enhancing observations for ground validation of the EarthCARE satellite, which is set to launch in 2023. This study focuses on using the dual-polarization Doppler weather radar, operated by the Japan Meteorological Agency. In terms of numerical models, we use and compare multi-models with single-moment (SM) and double-moment (DM) cloud microphysics schemes; the global non-hydrostatic model, Non-hydrostatic ICosahedral Atmospheric Model (NICAM) and the two regional models with A System based on a Unified Concept for Atmosphere (ASUCA) and Scalable Computing for Advanced Library and Environment (SCALE) are used. In particular, because NICAM can be used as both a global and a regional model, we can immediately test the improved scheme on a global scale for its effect on climatology and the evaluation of climate sensitivity. This paper introduces the methodology for evaluating numerical models by the dual-polarization radar using the observation simulator and compares numerical model results with observations. In particular, we evaluate the simulated rain in the lower level near the ground and the large ice particles just above the melting level. The simulation with NICAM-DM reproduces the comparable polarimetric radar characteristics of rain as the observation. However, the simulations with NICAM-SM and ASUCA-SM show larger raindrop sizes in stronger rain areas compared to the observation. For the larger ice particles just above the melting level around 4 km, NICAM-DM and ASUCA-SM overestimate particle sizes of graupel or snow, while NICAM-SM has a similar size of the ice particles. In future studies, we will use the present results to improve the cloud microphysics scheme, which will be tested on a global model. [ABSTRACT FROM AUTHOR]

Monitoring and predicting space weather activity is increasingly important given society's growing reliance on space-based infrastructure but is hampered by a lack of observational data. Airglow at 1083 nm from metastable helium He(23S) in the thermosphere has long been a target for remote-sensing instruments seeking to fill that gap; however, passive measurements of He(23S) fluorescence are limited by low brightness, and interpretation of these observations is complicated by the > 500 km depth of the He(23S) layer. Here, we demonstrate a lidar instrument that is able to stimulate and detect He(23S) fluorescence, and we present measured profiles of He(23S) density. These measurements provide crucial validation to space weather models, support predictions of peak number density (~ 1 cm−3) and the dependence of density on altitude, solar zenith angle, and season, and extend by a factor of 4 the maximum probed altitude range by an atmospheric profiling lidar. These measurements open the door for the development of more sophisticated lidars: by applying well-established spectroscopic lidar techniques, one can measure the Doppler shift and broadening of the He(23S) line, thereby retrieving profiles of neutral wind speed and temperature, opening a window for studying space weather phenomena. Metastable helium is a promising target for remote-sensing observations of Earth's thermosphere. This paper reports on the development of a resonance lidar capable of resolving metastable helium density profiles and presents initial results [ABSTRACT FROM AUTHOR]

In this paper we show that the concept of cooling and settling of the middle and upper atmosphere formulated in 1999 finds new experimental confirmations in various measurement data of the parameters of both the neutral and ionized components of the middle and upper atmosphere. At the same time, it is becoming more and more obvious that it is impossible to explain the entire range of observed long-term trends in the atmosphere and ionosphere by a mere increase in the CO2 content in the atmosphere. In particular, the main source of CO2 entering the atmosphere is the combustion of hydrocarbon fuels on an industrial scale, which binds free oxygen with carbon. On the other hand, oddly enough, the processes caused by the decrease in the O2 content in the atmosphere are not considered in any theoretical model designed to explain the observed phenomena. In the meanwhile, the effect of a sharp drop in the O2 concentration above the turbopause level is clearly recorded from the data on the response of the ionosphere to solar flares. [ABSTRACT FROM AUTHOR]

Mathematical modeling of mass transfer is widely used to study the spread of pollutants in the atmospheric air. One of the most important modeling problems is to understand the physics of vertical motions of fine particles in the surface layer of the atmosphere. In modern models, transport in the vertical direction is described by the movement of particles in turbulent flows, considering gravitational forces. Coincidence of simulation results with experiment can be obtained for stable states of the atmosphere. However, under conditions of atmospheric instability, the movement of particles in the vertical direction is also possible in ascending or descending convective flows. The paper estimates the average values of the vertical component of the velocity of fine particles of emissions from a coal-fired thermal power plant. The results were obtained using a semi-empirical method based on the use of an analytical solution of the stationary diffusion-convection transport equation and the measured horizontal profile of the pollution level in the surface layer of the atmosphere. Due to insignificant amount of particle fluxes, the profile was measured by the moss biomonitoring method, which provides long exposure times. Concentrations of chemical elements in emissions and accumulated in mosses during exposure were measured using neutron activation analysis. [ABSTRACT FROM AUTHOR]

The aim of this paper is to explore the connection between moods and meteors or atmospheric phenomena in Heidegger's thinking. The idea of the weather as something affecting our emotional state is not new but goes all the way back to Homer. However, the ontological basis of this connection is missing. In this paper, I argue that Heidegger provides exactly such an ontological account of moods and meteors not as two separate spheres but as a common atmosphere of attuned elementality—a dynamic interface where beings bend into being. Being can no longer be understood solely as that which determines beings qua beings but beings inform/transform being as well. [ABSTRACT FROM AUTHOR]

The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible. Measurement(s) net ecosystem exchange • carbon dioxide • water • energy Technology Type(s) eddy covariance • measurement device Sample Characteristic - Environment terrestrial biome • atmosphere Sample Characteristic - Location Earth (planet) Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12295910 [ABSTRACT FROM AUTHOR]

So far no designated mission to either of the two ice giants, Uranus and Neptune, exists. Almost all of our gathered information on these planets comes from remote sensing. In recent years, NASA and ESA have started planning for future mission to Uranus and Neptune, with both agencies focusing their attention on orbiters and atmospheric probes. Whereas information provided by remote sensing is undoubtedly highly valuable, remote sensing of planetary atmospheres also presents some shortcomings, most of which can be overcome by mass spectrometers. In most studies presented to date a mass spectrometer experiment is thus a favored science instrument for in situ composition measurements on an atmospheric probe. Mass spectrometric measurements can provide unique scientific data, i.e., sensitive and quantitative measurements of the chemical composition of the atmosphere, including isotopic, elemental, and molecular abundances. In this review paper we present the technical aspects of mass spectrometry relevant to atmospheric probes. This includes the individual components that make up mass spectrometers and possible implementation choices for each of these components. We then give an overview of mass spectrometers that were sent to space with the intent of probing planetary atmospheres, and discuss three instruments, the heritage of which is especially relevant to Uranus and Neptune probes, in detail. The main part of this paper presents the current state-of-art in mass spectrometry intended for atmospheric probe. Finally, we present a possible descent probe implementation in detail, including measurement phases and associated expected accuracies for selected species. [ABSTRACT FROM AUTHOR]

This paper discusses the effect of NaCl on the secondary oxidation rate of hot-briquetted iron (HBI) during its transportation to consumers in Russia, former Soviet republics, and other foreign countries by both rail and water transport. This results in distinct atmospheric conditions surrounding the briquettes, leading to varied oxidation processes. This study is significant as the oxidation rate directly affects the metallurgical properties of the briquettes. The article presents experimental investigations on the impact of different NaCl concentrations (0–4%) in water, which evaporates into the atmosphere surrounding HBI, on its reactivity. The findings reveal that the reactivity of briquettes increases with up to 4% NaCl content in the water surrounding the HBI. Consequently, the iron oxidation rate in the briquettes also rises, with reactivity increasing from 0.234 to 0.412 nm3/(ton·day) and the rate from 0.0833 to 0.1459 kg/day. These results suggest that seawater, particularly with NaCl content up to 4%, significantly impacts the iron oxidation rate in HBI. Therefore, when transporting by sea, it is essential to consider this influence and implement measures to mitigate this type of oxidation. [ABSTRACT FROM AUTHOR]

Space debris is an urgent problem of our time. This paper considers the idea of reducing near-Earth space debris by releasing the spent additional fuel tank (AFT) and the booster's central block (CB) into the Earth's atmosphere. The spacecraft transfer from a reference circular orbit of an artificial Earth satellite to a target elliptical orbit is optimized. The transition maneuvers are carried out using a booster with a high limited-thrust engine and the AFT. The second zonal harmonic of the Earth's gravitational field is taken into account. The optimal control problem is solved based on Pontryagin's maximum principle. Bulky derivatives are calculated using a specially developed numerical-analytical differentiation technique. The Pontryagin extremals obtained below are the next step in implementing the problem hierarchy methodology. [ABSTRACT FROM AUTHOR]

Projections of West African Monsoon (WAM) precipitation are uncertain. To address this, an improved understanding of the mechanisms driving WAM precipitation change is needed to shed light on inter-model differences and aid model development. The full forcing of increased CO2 can be decomposed into different components such as the impact of ocean warming, or the direct radiative effect of increased CO2. This paper investigates such a decomposition, analysing the effect of a uniform 4K ocean warming whilst keeping atmospheric CO2 concentrations constant. The analysis highlights several mechanisms acting to decrease WAM precipitation over a range of timescales, from days after the abrupt ocean warming, to the long-term equilibrium response. The initial decrease in WAM precipitation is caused by warming and enhanced convection over the ocean, stabilising the atmosphere inland and disrupting the monsoon inflow at low levels. Later in the response (after about 5 days), the WAM precipitation is reduced through a strengthening of the shallow circulation over West Africa, associated with changes in the large-scale temperature gradients and a local warming of the atmosphere related to a soil moisture feedback mechanism over the Sahel. Finally, from around 20 days after the SST increase, the WAM precipitation is also reduced through changes in specific humidity gradients that lead to increased potency of dry air advection into the monsoon rainband. The analysis concludes by demonstrating that the processes affecting precipitation in the early stages of the response are also relevant to the long-term equilibrium response. [ABSTRACT FROM AUTHOR]

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

The paper analyzes the trends in the average monthly concentrations of nitrogen dioxide in the period from 2005 to 2021 in 18 large cities in different geographical areas: St. Petersburg, Moscow, Kyiv, Donetsk, Helsinki, Warsaw, Istanbul, Athens, Rome, Milan, Barcelona, Madrid, Paris, London, and Amsterdam. It was found that, in all cities, the concentration of this gas decreases, but at different rates. The highest rate of change was recorded in cities with the highest gas content at the time of the initial stage—2005. A linear dependence of the average nitrogen dioxide concentration on the population and anthropogenic emissions was revealed according to HTAPv3 data. Approximately every 1 million people of the population of large cities is responsible for the formation of a gas concentration of ∼200 × 1015 molecules/cm2, regardless of the geographical location of the city. Every ∼10 000 t/month of nitrogen dioxide emissions based on HTAPv3 generate gas concentrations of ∼500 × 1015 molecules/cm2. Using these dependences, it is possible to estimate anthropogenic emissions of NO2 sources throughout the country, based on remote sensing data. The results of the study also indicate the possibility of verifying and correcting inventory databases of gas emissions based on satellite observations of the nitrogen dioxide content in the atmosphere. [ABSTRACT FROM AUTHOR]

In recent theoretical studies of the authors, some estimates of the atmospheric disturbances related to inhomogeneities of the gravity field (IGF) have been obtained. The main attention was paid to dynamic effects: disturbances of the wind field under the influence of IGF. In this paper, attention is drawn to the fact that noticeable thermal effects of IGF can also exist in the surface layer of the atmosphere. These inhomogeneities, deforming the fields of pressure, air density, and air temperature, affect the temperature regime of the boundary layer and the heat exchange of air with the underlying surface. An analytical model designed to estimate the magnitudes of these effects is considered. Based on the proposed model, an analytical solution is found for a linear stationary two-dimensional problem for perturbations caused by one horizontal harmonic of the IGF in a semi-infinite stably stratified medium rotating around a vertical axis. The temperature of the lower boundary (underlying surface) was assumed to be fixed. It was also assumed for this boundary that the no-slip and no-flow conditions are satisfied. The attenuation of all disturbances with height was also assumed. The essential similarity parameters in this problem are analogues of the Rayleigh and Taylor numbers, in which the given horizontal scale of IGF serves a spatial scale. Analytical expressions are obtained for the profiles of temperature perturbations and amplitudes of deviations of vertical heat fluxes on the surface. The latter, along with amplitudes of gravity field inhomogeneities, depend most strongly on the background stratification of the medium. In highly anomalous regions, the amplitudes of heat flux deviations, according to the estimates obtained, may reach and even exceed 1 W/m2, which gives grounds for taking into account the gravity field inhomogeneities in climatic calculations and numerical models of the atmosphere. [ABSTRACT FROM AUTHOR]

This paper presents a method for solving the inverse problem of thermal sounding using calibrated data from the ACS TIRVIM experiment on board the ExoMarsTrace Gas Orbiter. The 1.7–17 µm range TIRVIM Fourier spectrometer as part of the ACS instrument complex aboard the ExoMarsTGO operates in the nadir and solar occultation modes in orbit around Mars. The main scientific goal of TIRVIM in the nadir observation mode is the long-term constant monitoring of the thermal structure of the Martian atmosphere and the general content of aerosols and water vapor from measurements in the range of 5–16.7 µm (600–2000 cm–1). To process the TIRVIM nadir measurements, an algorithm was developed, allowing the retrieval of the vertical temperature profile from the surface to 60 km, the surface temperature, and the general content of dust and water ice in the atmosphere from the TIRVIM spectrum in the range of 600–1250 cm–1, as well as the water vapor column abundance according to measurements in the range of 1250–1830 cm–1. The processing method widely uses the achievements of previous similar experiments, taking into account the features of the TIRVIM spectra. Using the developed method 2.28 × 106 spectra obtained by TIRVIM in nadir by regular measurements, were processed with retrieval of the thermal structure up to 60 km altitude and the aerosol content in the atmosphere as well as additional 2.3 × 105 specially averaged TIRVIM spectra, were processed with retrieval of the water vapor column abundancein the Martian atmosphere. [ABSTRACT FROM AUTHOR]

The paper presents a one-dimensional aeronomic model of hydrogen–helium upper atmospheres of hot giant exoplanets based on the approximation of single-fluid multicomponent hydrodynamics. Chemical reactions and heating–cooling processes are taken into account. Typical cases of a hot Jupiter and a warm Neptune are considered as an example of the application of the model. Calculations were carried out for various values of the gas pressure at the photometric radius of a planet. In the solutions obtained, the transonic planetary wind is formed, which leads to a hydrodynamic outflow of the atmosphere with mass loss rates of about 1010 and 109 g/s for a hot Jupiter and a warm Neptune, respectively. At the same time, the outer layers of the atmosphere of a hot Jupiter become completely ionized, while the atmosphere of a warm Neptune mainly consists of neutral gas. In some variants of the hot Jupiter model, instability develops in the deep layers of the atmosphere, which may result in the formation of a specific cloud layer. [ABSTRACT FROM AUTHOR]

The paper addresses the development of prototype large-scale purified inert atmosphere cells for testing equipment used in the pyrochemical treatment of spent nuclear fuel from fast neutron reactors. In addition, design peculiarities of the cells are discussed along with a presentation of preliminary results of tests on the generation and maintenance of an inert atmosphere of required quality in them. [ABSTRACT FROM AUTHOR]

Among all habitability factors for terrestrial exoplanets, one of the most important is the presence of a secondary N2–O2 dominant atmosphere on an exoplanet. This factor can potentially indicate the already existing geological and biological processes on the exoplanet. Meanwhile, direct characterization of the N2‒O2 atmospheres of terrestrial exoplanets is a difficult observational task. There are only a few indicators (molecules) of such an atmosphere, among which one can single out a potential biomarker—a molecule of nitric oxide NO. The strongest spectral features of this molecule in the ultraviolet range are γ-bands (203‒248 nm). An important role in the search for potential biomarkers on exoplanets, including the detection of NO γ-bands, can be played by planned for the launch Spectr-UF (WSO-UV) space observatory. Estimates of the possibility of detecting the transmission of light in γ-bands in the atmospheres of exoplanets with this observatory are presented in this paper. The methods of emission and transmission spectroscopy are compared as applied to the detection of NO. Based on the results of this study, it is shown that there is a potential possibility of detecting a transmission signal in the NO γ-bands in the atmospheres of nearby exoplanets (<10 pc) using the LSS spectrograph of the Spectr-UF (WSO-UV) observatory. At the same time, the imposed restrictions for the detection of this signal on more distant exoplanets are presented. [ABSTRACT FROM AUTHOR]

The use of Hi-B steel in the manufacture of transformer cores can save raw materials and greatly reduce the volume and energy consumption of the transformer. A film of forsterite on the steel surface provides a certain degree of insulation and forms by the reaction between the internal oxidized zone (IOZ) and the MgO coating during the high-temperature annealing. Therefore, the IOZ morphology is the key to affect the film morphology. This paper studies the effect of annealing atmosphere and heating rate on the morphology evolution of IOZ during the first heating stage of high-temperature annealing. The main factors affecting IOZ morphology are discussed in the context of the influence of its morphology evolution on the film morphology. The results show the change trend of IOZ thickness on the steel with MgO coating is completely different from that without MgO coating. The IOZ thickness in the steel with or without MgO coating jointly affects the forsterite film thickness. [ABSTRACT FROM AUTHOR]

In this paper, we consider the peculiarities of using the microwave radiometry method for remote sensing of the thermal stratification of the high layers of the atmosphere: the stratosphere and the lower mesosphere in comparison with other high-altitude layers, the troposphere and the atmospheric boundary layer. Such peculiarities are a special choice of spectral channels and bandwidths, the use of limb geometry of measurements along with the nadir in satellite instruments, as well as taking into account the influence of the Zeeman effect. Characteristics for first-generation satellite microwave sounders that measure temperature profiles up to an altitude of 30 km, as well as for more modern ground-based and satellite instruments, the sounding altitude of which reaches 50 km with a nadir-measurement geometry and 100 km with a limb one, are given. The results obtained in experiments with high-altitude balloons and using experimental setups for measuring the absorption coefficient of molecular oxygen at nearly 60 GHz are presented. The capabilities of ground-based instruments for microwave remote sensing of the stratosphere temperature and the results of complex comparisons are also analyzed. [ABSTRACT FROM AUTHOR]

Abstract—Anomalous variations in radon emissions from the soil are sometimes observed before and after strong earthquakes. In this paper, we theoretically analyze the known hypothesis that these variations in radioactive emanations in the surface layer of the atmosphere cause variations in the vertical background current in the atmosphere with subsequent changes in the electron density in the lower ionosphere. For this purpose, we will first assess the relation between radon emission variations and the vertical atmospheric current flowing into the ionosphere. Then we will solve a model problem concerning the spatial distribution of plasma density and electric field perturbations occurring in the E-layer of the ionosphere caused by an inflowing vertical current. It was believed that the current flowing into this layer contains only an electron component and is attenuated only by the recombination of electrons. The estimate of the maximum variation is at least 3–5 orders of magnitude smaller than the observed anomalous variations, which allows us to conclude that this hypothesis is not plausible. [ABSTRACT FROM AUTHOR]

It was shown in a recent study [11] that taking into account the rotation of the Earth's atmosphere leads to the appearance of a new region of evanescent waves with a continuous frequency spectrum on the diagnostic diagram of acoustic-gravity waves. The region is located below the lower limit of gravity waves, which is equal to for all wavelengths, where is the angular frequency of the atmospheric rotation. This result was obtained for high-latitude regions of the atmosphere in which one can be limited to considering only the vertical component of the Earth's rotation frequency. This paper shows that taking into account both components of the vector of the atmospheric rotation frequency —horizontal, where is the local latitude, and vertical, —the dominant role in the acoustic-gravity wave propagation is played by the vertical component. It is shown that the horizontal component leads to a negligible modification of the boundaries of the regions of acoustic and gravity waves on the diagnostic diagram. It is also shown that the vertical component of the frequency affects most strongly the lower limit of gravity waves, which depends on the latitude of the observation site for all wavelengths and is equal to 2 . [ABSTRACT FROM AUTHOR]

A theoretical problem of linear stationary disturbances of the background geostrophic flow of a stratified rotating medium (atmosphere) that are induced by inhomogeneities of the gravitational field is considered. There is a common belief that such inhomogeneities may only somewhat deform (distort) the state of hydrostatic equilibrium, but cannot affect the dynamics of the flow in the atmosphere. Generally, the problem statement is different for the processes over a solid surface and a water surface, because a water surface (the lower boundary condition for the atmosphere) is deformed by inhomogeneities of the gravitational field. The problem of disturbances over a water surface has been considered in recent papers of the authors; in this paper, the results are developed and significantly revised. The emphasis is on disturbances over a flat horizontal surface, which were not examined before. From the analytical solutions, it follows that the influence of inhomogeneities of the gravitational field on the atmospheric flows may be significant in some cases. Physical generation mechanisms of disturbances are analyzed. [ABSTRACT FROM AUTHOR]

In this paper, we investigate a comparative analysis of some Generalized Laguerre–Gaussian Schell-model beams through a paraxial ABCD optical system in a turbulent atmosphere. Based on the extended Huygens–Fresnel diffraction integral, analytical expressions for the spectral density in the receiver plane of the studied beams are derived in detail. By studying the effects of the source coherence parameters and the atmospheric turbulence strength, the numerical results indicate that the profile of these Schell-model beams takes different shapes during their propagation. [ABSTRACT FROM AUTHOR]

In this paper, the effect of oxygen and steam on the decomposition of inorganic sulphur in coal in the oxy-fuel atmosphere is investigated using the thermodynamic equilibrium calculation method. To evaluate sulphur distribution in different gas environments, the authors apply the HSC Chemistry software for calculations of various sulphur-related chemical reactions and equilibria parameters, based on the principle of minimizing the Gibbs free energy. The influence of temperature and gas atmospheres on the equilibrium composition is also evaluated. In the thermodynamic calculation, the FeS2 and FeSO4 substances are used to simulate the pyrite and sulphate impurities in coal, respectively. The relationships are established between the CO2 atmosphere and the inorganic sulphur content. It is shown, that the CO2 presence in the atmosphere enhances the formation of FeO and the decomposition of FeS, resulting in a few intermediate products, including Fe2O3, Fe3O4, Fe2S3, FeCO3, and COS. The results show that oxygen has a significant effect on the sulpher distribution. Thе SO, FeO, and Fe3O4 products are formed in the oxygen-deficient environment, while the SO2 and Fe2O3 substances are formed when oxygen is in excess. In the O2 /CO2 /H2O mixture atmosphere, the oxidation reaction of the sulphur-containing compounds becomes more complicated. A competitive relationship between the reactions of S-CO2 and S-H2O is observed. [ABSTRACT FROM AUTHOR]

Abstract—The term "Big Data" has become very popular over the past decade. The frequency of its use in the research papers, reports, and broad press has been steadily increasing. This work describes the origin and development of the theory and practice of Big Data as a scientific discipline, outlines the main characteristics and methods for Big Data processing and analysis, discusses the formalism and family of Big Data V-characteristics, and presents the examples of the sources of the growing Big Data which have fundamental effect on the development of geophysics and related Earth sciences. The examples of the sources of Big Data in the Earth sciences are remote sensing, meteorology, geoecology (in terms of the global hierarchical network SMEAR (Stations Measuring Earth surfaces and Atmosphere Relations)), and seismic exploration. Besides, we discuss seismic monitoring data which can become Big Data when combined with other geophysical information and consider geomagnetic data which are not Big Data but nevertheless have a great scientific value. [ABSTRACT FROM AUTHOR]

A recent paper by Hoyningen-Huene argues that the Chemical Revolution is an excellent example of the success of Kuhn's theory. This paper gives a succinct account of some counter-arguments and briefly refers to some further existing counter-arguments. While Kuhn's theory does have a small number of more or less successful elements, it has been widely recognised that in general Kuhn's theory is a 'preformed and relatively inflexible framework' (, p. 24) which does not fit particular historical examples well; this paper clarifies that those examples include the Chemical Revolution. [ABSTRACT FROM AUTHOR]

The paper aims to study in detail the structure of seismic noise before and after the Sumatra mega-earthquake with M = 9.1 of December 26, 2004. The records by the IRIS seismic stations in different regions of the world, equipped with STS-1 seismometers providing ground motion velocity recording in a broad range of periods from 0.2 to 360 s with the use of standard equipment, form the empirical base of the research. In the records of each station, intervals free of earthquakes, interference from manmade impacts, and noise enhancement due to cyclone propagation were selected. The amplitude of steady seismic noise in the range from 40 to 360 s, not complicated by the recordings of earthquakes and effects of meteorological origin, is in the order of 20 to 40 nm, which characterizes the actual resolution of a broadband seismic station. The noise bursts in the ranges 40–80, 80–160, and 160–320 s differ by the shape and time of occurrence suggesting different sources of their generation. The absence of the correlation between the noise recordings at the neighboring seismic stations spaced 102–103 km apart indicates the influence of local processes. The noise reflects turbulent processes in the Earth's atmosphere, whereas the exponential growth of the noise with the increase of the oscillation period is consistent with A.N. Kolmogorov's theory of locally isotropic turbulence in the atmosphere. The noise amplitude after the Sumatra mega-earthquake with M = 9.1 of December 26, 2004 increased by a factor of 1.5–2 in January 2005 compared to January 2004, irrespective of the location of the seismic station. [ABSTRACT FROM AUTHOR]

The phase shift between changes in the global surface temperature Tg and atmospheric CO2 content has been shown earlier not to characterize causal relationships in the Earth system in the general case. Specifically, the sign of this phase shift under nongreenhouse radiative forcing changes depends on the time scale of this forcing. This paper analyzes the phase shift between changes in the global surface temperature Tg and the atmospheric CO2 content under synchronous external emissions of carbon dioxide and methane into the atmosphere on the basis of numerical experiments with the IAP RAS climatic model and a conceptual climate model with carbon cycle. For a sufficiently large time scale of external forcing, the changes in lag relative to the corresponding changes in Tg. [ABSTRACT FROM AUTHOR]

The paper presents reconstructions of the heliospheric modulation potential based on data on the content of the cosmogenic isotope 10Be in the ice layers of Antarctica (Dome Fuji). The calculations involve the use of two models that describe the relationship between the 10Be concentration in layers of ice C with the rate of formation of this isotope in the Earth's atmosphere Q. The first model is described by a linear relationship between these quantities with a constant proportionality coefficient. In the second case, the proportionality coefficient between the concentration C and production rate Q changes over time in the considered model. The differences in the obtained reconstructions of the heliospheric modulation potential from Antarctica data from the reconstruction based on NGRIP data (Greenland) are analyzed. It was shown that the contradictions between the reconstructions can be removed if the dependence of the 10Be concentration in ice layers on the rate of its formation in the Earth's atmosphere changes with time, which may be the result of climate change. Moreover, these dependences may be different for different regions. [ABSTRACT FROM AUTHOR]

In this paper, we present a theoretical study of the propagation properties for Generalized Humbert-Gaussian beams (GHGBs) passing through a turbulent atmosphere. The axial intensity distribution of beams propagating through atmospheric turbulence is evaluated analytically based on the Huygens-Fresnel diffraction integral and the Rytov theory. The impact of the incident beam parameters and the turbulent strength on the output axial intensity is investigated through numerical illustrations. The results show that the propagation of GHGBs is faster when the atmosphere is very turbulent for small wavelength and small beam waist. [ABSTRACT FROM AUTHOR]

The paper provides an overview of methods and technical devices for remote temperature and humidity sensing of the Earth's atmosphere from satellites developed in Russia. A brief description of modern and forthcoming infrared and microwave atmospheric sounders installed on Meteor-M operational polar-orbiting weather satellites is given. The physical and mathematical base of interpreting measurements of atmospheric sounders (IKFS-2 infrared Fourier spectrometer and MTVZA-GYa microwave radiometer) is presented. The technologies for retrieving atmospheric temperature and humidity profiles are described. The results of retrieval validation as well as the prospects for further development of satellite remote temperature and humidity sensing systems are discussed. [ABSTRACT FROM AUTHOR]

This essay considers the ramifications of "The Umbrella Man" - a brief mystery that was of interest to historians and theorists examining the assassination of John F. Kennedy in 1963 - on the practice of modern archaeology and some of the basic tenets upon which it relies. The paper focuses on certain materials, analytical methods, and research themes associated with the study of nineteenth-century sites in the Midwest, contextualized to varying degrees by the presence of a written record left behind by the makers and users of the material world as it existed in the region during the 1800s. [ABSTRACT FROM AUTHOR]

Muonography is an analog of other similar concepts such as X-ray radiography, electronography, neutronography, etc. based on the detection of penetrating radiation whose interaction with objects under study causes changes in the initial flux of the used particles. Unlike all other "graphies" which use artificially formed particle fluxes, muons are of natural origin, since they are formed as a result of interactions of primary cosmic rays with the nuclei of atoms in the atmosphere. Since muons keep well the direction of motion of primary particles, muon flux allows studying of disturbances in the heliosphere and magnetosphere of the Earth which lead to variations of the flux of primary cosmic rays. Also, disturbances in the atmosphere directly affect the muon flux, thus it can be used to study atmospheric processes. The paper considers the main ideas of the method of muonography, as well as the examples of its application for studying various processes and phenomena in the heliosphere, magnetosphere and atmosphere of the Earth. In frames of the further development of muonography, we discuss the expediency of creating a network of muon hodoscopes in the Russian Federation for early detection of hazardous processes and phenomena over its territory. [ABSTRACT FROM AUTHOR]

Advances in attacking the problem of radiative transfer in the near infrared (NIR) bands of CO and CO under nonlocal thermodynamic equilibrium (NLTE) conditions depend on the accuracy of taking into account the radiation processes and inelastic collisions of CO and CO molecules. The focus of the paper is to substantially improve the physical model of the problem and update the calculation method. It is the first time the surface albedo is introduced into the problem of the molecular emission under NLTE conditions. The values of the rate constants for inelastic molecular collisions and their temperature dependences have been radically updated. In some cases, since laboratory measurements of these constants are lacking, different versions are provided for them. The relative abundance of CO and CO isotopologues is based on the ratios of isotope abundances for the elements C and O obtained from the measurements in the atmosphere of Mars. The intensity of extraterrestrial solar NIR radiation is specified on the base of the high-accuracy ground-based measurements. In the method for calculating the populations of vibrational states, we pioneer in completely taking into account the overlapping of spectral lines in the NIR bands of CO and CO. [ABSTRACT FROM AUTHOR]

The modern picture of the neutrino as a multiple-mass, highly mixed neutral particle has emerged over forty years of study. Best known of the issues leading to this picture was the apparent loss of neutrinos coming from the sun. This article describes another piece of evidence that supports the picture; the substantial reduction of high-energy muon-type neutrinos observed in nature. For much of the forty-year period before the modern picture emerged, this observation was known as the 'atmospheric neutrino anomaly,' since these neutrinos originate in the Earth's atmosphere. This paper describes the discovery of the atmospheric neutrino anomaly. I explore the scientific context and motivations in the late 1970s, from which this work emerged. The gradual awareness that the observations of atmospheric neutrinos were not as expected took place in the 1983-1986 period. [ABSTRACT FROM AUTHOR]

We study the vertical propagation of acoustic waves in a strongly inhomogeneous atmosphere. The class of monotonically varying profiles for the sound velocity, gas density, and gas pressure, for which acoustic waves can propagate with no reflection outside the framework of the classical WKB approximation, is found. This class of solutions, called reflectionless, is obtained by transforming the levels for waves in an ideal gas located in the gravity field into the Euler—Darboux—Poisson equation of a special kind, which has a solution in the form of a superposition of non-interacting waves propagating in opposite directions. It is noted that with this stratification, acoustic waves can have any frequency, in contrast to the exponential atmosphere, where the cutoff frequency is present. [ABSTRACT FROM AUTHOR]

The study of solar irradiance variability is of great importance in heliophysics, Earth's climate, and space weather applications. These studies require careful identifying, tracking and monitoring of features in the solar photosphere, chromosphere, and corona. Do coronal bright points contribute to the solar irradiance or its variability as input to the Earth atmosphere? We studied the variability of solar irradiance for a period of 10 years (May 2010 – June 2020) using the Large Yield Radiometer (LYRA), the Sun Watcher using APS and image Processing (SWAP) on board PROBA2, and the Atmospheric Imaging Assembly (AIA), and applied a linear model between the segmented features identified in the EUV images and the solar irradiance measured by LYRA. Based on EUV images from AIA, a spatial possibilistic clustering algorithm (SPoCA) is applied to identify coronal holes (CHs), and a morphological feature detection algorithm is applied to identify active regions (ARs), coronal bright points (BPs), and the quiet Sun (QS). The resulting segmentation maps were then applied on SWAP images, images of all AIA wavelengths, and parameters such as the intensity, fractional area, and contribution of ARs/CHs/BPs/QS features were computed and compared with LYRA irradiance measurements as a proxy for ultraviolet irradiation incident to the Earth atmosphere. We modeled the relation between the solar disk features (ARs, CHs, BPs, and QS) applied to EUV images against the solar irradiance as measured by LYRA and the F10.7 radio flux. A straightforward linear model was used and corresponding coefficients computed using a Bayesian method, indicating a strong influence of active regions to the EUV irradiance as measured at Earth's atmosphere. It is concluded that the long- and short-term fluctuations of the active regions drive the EUV signal as measured at Earth's atmosphere. A significant contribution from the bright points to the LYRA irradiance could not be found. [ABSTRACT FROM AUTHOR]

The goal of this paper is to assess the current status and trends of total mercury (THg) contamination of the atmosphere and terrestrial ecosystems in Poland. The study shows that the reduced domestic and worldwide atmospheric emission of Hg resulted in decreased THg level in the terrestrial biotope and biosphere. Considering that Poland is one of the main Hg emitters in Europe, the THg concentrations in its abiotic environment are still elevated. However, the THg level in terrestrial organisms is relatively low, which is because a large proportion of Hg deposited on land is accumulated in organic-rich soils. Regarding the THg concentration, consumption of wildlife and livestock from Poland is safe for humans. Nevertheless, the authors indicate the need for effective environmental monitoring, based on selected bioindicators, which is crucial considering the slowing reduction of Hg emission combined with the consequences of the changing climate. [ABSTRACT FROM AUTHOR]

The atmosphere is an evolutionary agent essential to the shaping of a planet, while in oceanic science and daily life, liquids are commonly seen. In this paper, we investigate a generalized variable-coefficient Korteweg-de Vriesmodified Korteweg-de Vries equation for the atmosphere, oceanic fluids and plasmas. With symbolic computation, beginning with a presumption, we work out certain scaling transformations, bilinear forms through the binary Bell polynomials and our scaling transformations, N solitons (with N being a positive integer) via the aforementioned bilinear forms and bilinear auto-Bäcklund transformations through the Hirota method with some solitons. In addition, Painlevé-type auto-Bäcklund transformations with some solitons are symbolically computed out. Respective dependences and constraints on the variable/constant coefficients are discussed, while those coefficients correspond to the quadratic-nonlinear, cubic-nonlinear, dispersive, dissipative and line-damping effects in the atmosphere, oceanic fluids and plasmas. [ABSTRACT FROM AUTHOR]