1,745 results
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2. A review on air–sea exchange of reactive trace gases over the northern Indian Ocean.
- Author
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Gupta, Mansi, Tripathi, Nidhi, Malik, T G, and Sahu, L K
- Subjects
TRACE gases ,SURFACE of the earth ,ATMOSPHERIC chemistry ,ATMOSPHERE ,OCEAN ,TROPICAL cyclones ,HALOCARBONS ,ACETONE - Abstract
In the Earth's atmosphere, greenhouse gases (GHGs) and reactive trace gases are essential components of chemistry–climate interactions. These trace gases are emitted from both natural and anthropogenic sources over terrestrial and marine regions. Air–sea exchange is the dominant process controlling the distribution of several important trace gases over remote marine regions. Although the ocean–atmosphere interface covers ~70% of the Earth's surface, the quantitative air–sea exchange of reactive trace gases is estimated over the limited oceanic regions. The production and air–sea exchange of trace gases are controlled by physical conditions at both sides of the interface and ocean biogeochemistry. The northern Indian Ocean (NIO) experiences strong seasonal monsoon winds and intense tropical cyclones. Consisting of the Arabian Sea and the Bay of Bengal, it is one of the most biologically productive regimes of the world ocean and home to the intense oxygen minimum zone (OMZ) of the Arabian Sea with dissolved oxygen concentrations. Thus, the NIO offers a unique system to investigate the air–sea exchange processes of reactive trace gases. So far, most of the studies of air–sea exchange of trace gases is focused on the Atlantic and Pacific Oceans, while studies over the northern Indian Ocean are very limited and reported mainly for CH
4 , CO2 and N2 O. Although progress has been made in recent years, studies of air–sea exchange of reactive trace gases such as non-methane hydrocarbon (NMHCs), oxygen-, sulfur- and halogen-containing hydrocarbons remain scarce. This paper addresses the current understanding of air–sea exchange processes and fluxes of reactive trace gases, including NMHCs, dimethyl sulfide (DMS), oxygenated volatile organic compounds (OVOCs), halocarbons, carbon monoxide (CO) and ozone (O3 ) in the northern Indian Ocean. This review summarizes the studies on the air–sea exchange of trace gases over the northern Indian Ocean and common parametrization approaches used to estimate the air–sea flux of gases. Flux range for ethene (3–10.35 µmol m–2 d–1 ), isoprene (0.215–0.172 µmol m–2 d–1 ), acetaldehyde (–6.75–11.35 µmol m–2 d–1 ), acetone (–9–9 µmol m–2 d–1 ), DMS (0.03–41.4 µmol m–2 d–1 ) and CO (1.4–5.4 µmol m–2 d–1 ) over the NIO were summarized from various in-situ and modelling studies. The paper addresses the importance of the northern Indian Ocean apropos the production and exchange of reactive trace gases, the knowledge gaps and the future scientific scope. Additionally, it emphasizes the need for a multidisciplinary study of oceanic reactive trace gas cycling and its impact on regional atmospheric chemistry over the northern Indian Ocean. [ABSTRACT FROM AUTHOR]- Published
- 2024
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3. On applicability limits of Zhukovsky’s model for gliding flight.
- Author
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Vlakhova, A.
- Subjects
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PAPER , *GLIDING & soaring , *AIRCRAFT carriers , *ENGINES , *FLIGHT , *ATMOSPHERE , *DENSITY - Abstract
In the problem of gliding flight, i.e., aircraft longitudinal movement with its engines switched off, the aircraft was traditionally assumed to be an absolutely rigid body, the Earth was not rotating and had a plane surface, and the atmosphere was quiet. Further, the attack angle and the air density were assumed constant. The aim of this paper is to discuss the applicability limits of these assumptions. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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4. UAE's Atmospheric Ground Conditions for Free Space Optical Applications: Measurement and Analysis.
- Author
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Elayoubi, Karim, Coronel, Juan, Al Ahmadi, Asma, Al Ameri, Reem, Alteneiji, Aaesha, Alameri, Jawaher, Bouchalkha, Abdellatif, Matras, Guillaume, and Kasmi, Chaouki
- Abstract
Optical beam propagation through the atmosphere is suffering from turbulence condition and scattering due to the refractive index effects on propagation. In this paper, we study optical beam propagation under the UAE's weather conditions. An outdoor test was carried out to gather the atmosphere parameters (temperature, wind, humidity, and refractive index) and feed them to a beam propagation model. The beam centroid was determined to study and predict the effects on it at different periods of the day. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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5. Mathematical Simulation of the Atmospheric Electric Field Disturbance during a Geomagnetic Storm on 17 March 2015.
- Author
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Zamay, S. S., Denisenko, V. V., Klimenko, M. V., Klimenko, V. V., and Anisimov, S. V.
- Abstract
It follows from the observational data that variations of the atmospheric electric field occur during geomagnetic storms. In this paper, we present the simulation results of ionospheric electric fields during the main phase of the geomagnetic storm on March 17, 2015, within the framework of a quasi-stationary model of a conductor consisting of the atmosphere and the ionosphere. For this purpose, the satellite data on the global distribution of currents between the magnetosphere and the ionosphere are used to describe the magnetospheric source of the electric field. A variation of the electric potential in the ionosphere leads to a variation of the electric field in the entire atmosphere, including its surface layer. It is important that during a geomagnetic storm, the observatory in which the atmospheric electric field is measured significantly changes its position relative to the direction of the Sun. This leads to significant changes in the ionospheric conductivity above the observatory, which affects both the ionospheric electric field and the atmospheric part of the global electrical circuit (GEC). Therefore, when assessing the effect of a geomagnetic storm on the atmospheric electric field in a particular observatory, it is necessary to take into account the local time when comparing the measurement data with the geomagnetic activity indices. For the storm on March 17–18, 2015, we found that taking into account the variations of the ionospheric electric field when calculating the atmospheric electric field allowed us to reproduce the disturbances of the fair weather electric field observed at the Borok Geophysical Observatory. Based on the simulation results, it is shown that during extremely strong magnetic storms, additional atmospheric electric field variations in some places on the Earth have the same scale as the fair-weather field itself. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Atmosphere and ocean interactions.
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Zardi, Dino
- Abstract
The nature and extent of the main interactions between the Earth's atmosphere and the ocean are briefly reviewed, introducing the main properties of these two planetary systems, the hierarchy of timescales and spatial scales characterizing their processes, and the main mechanisms involved. To clarify these mechanisms, a few examples of exchanges of momentum, energy, and mass exchanges are briefly outlined. The paper aims at stimulating students to discover the fascinating interplay among two of the most relevant components of our planet, such as the atmosphere and the ocean, and suggests resources for further exploration. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Temporary storage of carbon in the biosphere does have value for climate change mitigation: a response to the paper by Miko Kirschbaum.
- Author
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Dornburg, Veronika and Marland, Gregg
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BIOSPHERE ,GREENHOUSE gas mitigation ,CLIMATE change ,GREENHOUSE gases & the environment ,GLOBAL warming ,ATMOSPHERE ,CARBON dioxide & the environment ,GEOBIOLOGY - Abstract
Kirschbaum (Mitig Adapt Strat Glob Change 11:1151-1164, 2006) explores the climatic impact over time of temporarily sequestering carbon from the atmosphere. He concludes that temporary storage of carbon in the terrestrial biosphere ''achieves effectively no climate-change mitigation''. His strongly worded statement begs for a response. This paper argues that Kirschbaum's conclusion is an artifact of the specific perspective of his analysis and his choice of a definition for climate-change impact. Even temporary sinks put us on a lower path for climate change, a path that will not otherwise be accessible. For carbon sinks in the terrestrial biosphere, we argue that sooner is better and longer is better, but even known temporary sinks have value. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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8. Study of Radiation Characteristics of Shock-Heated Gases.
- Author
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Kozlov, P. V., Levashov, V. Yu., Gerasimov, G. Ya., Zabelinskii, I. E., and Bykova, N. G.
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ATMOSPHERE ,ORBITAL velocity ,ELECTROMAGNETIC spectrum ,RADIATION ,SHOCK tubes - Abstract
The paper presents the results of studies with the use of shock tubes at the Institute of Mechanics of the M. V. Lomonosov Moscow State University, in which measurements were made of the radiation of shock-heated gases simulating the conditions of the entry of spacecraft into the atmosphere of the Earth and other planets of the Solar system with orbital and superorbital velocities. A description of the measuring equipment is given, as well as techniques of diagnostics and processing of the obtained spectroscopic information. Numerous experimental data on the radiation of shock-heated gases in a wide range of the radiation spectrum from vacuum ultraviolet to infrared have been analyzed, which serve as the basis for the development of various gas-dynamical models. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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9. National indicators of climate changes, impacts, and vulnerability.
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Kenney, Melissa A. and Janetos, Anthony C.
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CLIMATE change ,DISSOLVED oxygen in water ,WEST Nile fever ,SOCIAL scientists ,WILDLAND-urban interface ,ATMOSPHERE - Abstract
This article is part of a Special Issue on "National Indicators of Climate Changes, Impacts, and Vulnerability" edited by Anthony C. Janetos and Melissa A. Kenney Introduction Climate assessment efforts in the USA are a legally required and important process to share the state of knowledge about status and projected trends of climate changes and impacts and are used to support risk management decisions and policies (Jacobs et al. [11]). Contributions to this special issue The first paper in this special issue is I A framework for national climate indicators i (Kenney et al. [19]). In the first topical paper, I Toward an integrated system of climate change and human health indicators: a conceptual framework i (Liu et al. in preparation), the human health implications of climate change were explored to identify indicators. In I Indicators of climate change in agricultural systems i (Hatfield et al. [10]), the authors develop a conceptual framework that links the climate system to crop and livestock productivity as well as the impacts of land on other grassland and forest systems. [Extracted from the article]
- Published
- 2020
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10. Carbon Dioxide Emissions from Freshwater Systems in Western Siberia.
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Arshinov, M. Yu., Belan, B. D., Davydov, D. K., Simonenkov, D. V., and Fofonov, A. V.
- Abstract
One of the possible sources of carbon dioxide emission into the atmosphere can be river ecosystems. The paper presents the results of measuring CO
2 fluxes from the surface of several rivers and lakes in Tomsk Region. In the experimental period, average carbon dioxide fluxes were 143.7 ± 21.7 (August 13–14, 2023), 53.3 ± 21.2 (August 19), and 80.4 ± 59.9 mgC m−2 h−1 for the Ob River; 66.1 ± 17.3 mgC m−2 h−1 for the Ket River; 33.3 ± 17.3 mgC m−2 h−1 for the swamp Karasevoye Lake, 50.2 ± 23.0 mgC m−2 h−1 for the Suiga River, and 81.9 ± 11.5 mgC m−2 h−1 for the Iksa River. The flux magnitudes significantly depended not only on the object of the study, but also on hydrometeorological conditions. [ABSTRACT FROM AUTHOR]- Published
- 2024
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11. Two-Stream Approximation to the Radiative Transfer Equation: A New Improvement and Comparative Accuracy with Existing Methods.
- Author
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Temgoua, F. Momo, Nguimdo, L. Akana, and Njomo, D.
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RADIATIVE transfer equation , *TERRESTRIAL radiation , *ZENITH distance , *SOLAR radiation , *ATMOSPHERE - Abstract
Mathematical modeling of the interaction between solar radiation and the Earth's atmosphere is formalized by the radiative transfer equation (RTE), whose resolution calls for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the RTE with the development of the phase function and the intensity into a third-order series of Legendre polynomials. This new approach, which adds one more term in the expression of the intensity and the phase function, allows in the conditions of a plane parallel atmosphere a new mathematical formulation of γ parameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined Delta Function and Modified Eddington, and second-order approximation methods with reference to the Discrete Ordinate (Disort) method (δ–128 streams), considered as the most precise. This work also determines the conversion function of the proposed New Method using the fundamental definition of two-stream approximation (F-TSA) developed in a previous work. Notably, New Method has generally better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, New Method shows very good precision for wide domains of the zenith angle μ0, but tends to deviate from the Disort method with the zenith angle, especially for high values of optical thickness. In spite of this divergence in reflectance for high values of optical thickness, very strong correlation with the Disort method (R ≈ 1) was obtained for most cases of optical thickness in this study. An analysis of the Legendre polynomial series for simple functions shows that the high precision is due to the fact that the approximated functions ameliorate the accuracy when the order of approximation increases, although it has been proven that there is a limit order depending on the function from which the precision is lost. This observation indicates that increasing the order of approximation of the phase function of the RTE leads to a better precision in flux calculations. However, this approach may be limited to a certain order that has not been studied in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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12. Microplastic pollution as an environmental risk exacerbating the greenhouse effect and climate change: a review.
- Author
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Li, Kui, Du, Linsen, Qin, Chanyuan, Bolan, Nanthi, Wang, Hailong, and Wang, Hua
- Subjects
GREENHOUSE effect ,GREENHOUSE gases ,CARBON-based materials ,ENVIRONMENTAL risk ,ATMOSPHERIC carbon dioxide ,CLIMATE change & health ,CLIMATE change - Abstract
Microplastics are polymer-based materials with carbon as their main framework. During degradation, they release greenhouse gases such as carbon dioxide and methane. Additionally, environmental microplastics can enter plant tissues, triggering oxidative stress in plant cells, adversely affecting photosynthesis, metabolism, gene expression, and other growth parameters. This reduction in plant efficiency in sequestering and utilizing atmospheric carbon dioxide indirectly impacts global carbon cycling, exacerbating the global greenhouse effect. Furthermore, environmental microplastics significantly alter soil structure and the composition of microbial communities, affecting the emissions of greenhouse gases such as carbon dioxide, methane, and nitrous oxide, thus indirectly promoting greenhouse gas emissions. Increasing research suggests a mutual reinforcement between microplastic pollution and global climate warming, where microplastic pollution exacerbates global climate warming, and the rise in global average temperature leads to the resuspension of microplastics in sediments, intensifying microplastic pollution in the environment. This article primarily focuses on the impacts of environmental microplastic pollution on different ecosystems and the relationship between microplastic pollution and global climate warming. It summarizes the effects of microplastic pollution on greenhouse gas emissions in marine, terrestrial, and atmospheric ecosystems, as well as the mechanisms by which microplastics and climate change affect ecosystem services. By delving into the intricate connection between microplastic pollution and greenhouse gas emissions, this paper aims to raise awareness of the climate change caused by microplastic pollution and calls for further research on the impacts of microplastics on ecosystems and global climate change, with the ultimate goal of protecting ecosystems and human health. Highlights: • MPs influence microbial communities, indirectly promoting GHG emissions. • MPs hinder plant photosynthesis, reducing CO
2 sequestration efficiency. • MPs pollution and climate change interact and exacerbate each other. • Human intervention and regulation can mitigate the impact of MPs on global warming. [ABSTRACT FROM AUTHOR]- Published
- 2024
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13. Effect of a Model Fire on Atmospheric Turbulence Characteristics.
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Loboda, E. L., Lutsenko, A. V., Kasymov, D. P., Agafontsev, M. V., and Kolesnikov, I. A.
- Abstract
This paper presents the analysis and generalization of the results of studies of turbulence in flame and in the vicinity of a combustion source during model steppe and crown fires performed at the Basic Experimental Complex of Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, in the period from 2019 to 2022. The spectra of air temperature changes and the scales of induced atmospheric turbulence in the vicinity of the front of a model fire are obtained. The ranges of air temperature pulsation frequency corresponding to the inertial and dissipative sections of the energy spectrum are found for a steppe fire; dissipative processes start running at an altitude of 10 m at wavenumbers with log k > 1.58 and the corresponding pulsation frequency f > 3 Hz; no dissipative processes are observed at an altitude of 3 m. During a model crown fire, turbulent processes in the atmosphere correspond to the inertial part of the energy spectrum at an altitude of 10 m; dissipative processes hardly manifest themselves. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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14. The Influence of Smoke from the Yakut Fires on the State of the Environment in Krasnoyarsk in August 2021.
- Author
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Shaparev, N. Ya., Tokarev, A. V., and Yakubailik, O. E.
- Abstract
The paper considers changes in the state of the environment in Krasnoyarsk and its environs during the existence of the smoke of large-scale Yakut fires in August 2021. The appearance of smoke aerosols in the atmosphere weakens the solar radiation flux reaching the Earth's surface and, accordingly, decreases the temperature of the active soil layer and the surface air layer. Advection of cooled air with high relative humidity over the surface of the Yenisei River in the lower downstream of the Krasnoyarsk HPP formed cooling fogs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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15. Call for papers: Special Issue of Earth, Planets and Space (EPS) Coupling Processes in the Equatorial Atmosphere (CPEA)
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Mamoru Yamamoto, N. Balan, Shoichiro Fukao, Tetsuo Nakazawa, and Subramanian Gurubaran
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Physics ,Atmosphere ,Coupling (physics) ,Space and Planetary Science ,Planet ,Geology ,Earth (chemistry) ,Geophysics ,Space (mathematics) ,Astrobiology - Full Text
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16. Air Composition over the Russian Arctic: 1—Methane.
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Antokhina, O. Yu., Antokhin, P. N., Arshinova, V. G., Arshinov, M. Yu., Belan, B. D., Belan, S. B., Guruleva, E. V., Davydov, D. K., Ivlev, G. A., Kozlov, A. V., Law, K., Rasskazchikova, T. M., Paris, J.-D., Savkin, D. E., Simonenkov, D. V., Sklyadneva, T. K., Tolmachev, G. N., and Fofonov, A. V.
- Abstract
In the Arctic, global warming is 2–3 times faster than over other regions of the globe. As a result, noticeable changes are already being recorded in all areas of the environment. However, there is very little data on such changes in the Russian Arctic. Therefore, to fill the gap in the data on the vertical distribution of the gas and aerosol composition of air in this region, an experiment was carried out on the Tu-134 Optik flying laboratory in September 2020 to sound the atmosphere and water surface over the water areas of all seas in the Russian Arctic. This paper analyzes the spatial distribution of methane. It is shown that during the experiment its concentration was the highest over the Kara Sea (2090 ppb) and the lowest over the Chukchi Sea (2005 ppb). The East Siberian and Bering Seas were slightly different from the Chukchi Sea in terms of the methane concentration. Average values of CH
4 are characteristic of the Barents (2030 ppb) and the Laptev Seas (2040 ppb). The difference between the concentrations at an altitude of 200 meters and in the free troposphere attained 150 ppb over the Kara Sea, decreased to 91 and 94 ppb over the Barents and Laptev Seas, and further decreased over the East Siberian, Chukchi, and Bering Seas to 66, 63, and 74 ppb, respectively. Horizontal heterogeneity in the distribution of methane over the Arctic seas is the greatest over the Laptev Sea, where it attained 73 ppb. It is two times higher than over the Barents and Kara Seas, and 5–7 times higher than over the East Siberian and Bering Seas. [ABSTRACT FROM AUTHOR]- Published
- 2023
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17. The Controlled Atmosphere Cone Calorimeter: A Literature Review.
- Author
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Bray, Robert John, Tretsiakova-McNally, Svetlana, and Zhang, Jianping
- Subjects
LITERATURE reviews ,FLAMMABLE materials ,CALORIMETERS ,ATMOSPHERE ,CHIMNEYS - Abstract
Cone calorimeters are widely used to assess heat release parameters and flammability of combustible materials, but their use is limited for applications where the global equivalence ratio (GER) exceeds one, because they can only replicate burning in open conditions. The standardisation of the controlled atmosphere cone calorimeter (CACC) in the ISO/TS 5660-5:2020 offers an opportunity to investigate the potential advantages and limitations of this apparatus. This paper presents a detailed review of existing studies conducted using the CACC. The review is aimed at examining the importance of atmospheric control for bench-scale experimental methods and the research-based development of key features of the apparatus. In addition, it highlights the research yet to be carried out to optimise the use of CACC as a tool in fire science. The effects of various design parameters are discussed including the method used for GER control, the chimney, the chamber, the gas inflow rate and others. Despite standardisation, it is concluded that there is limited consensus on optimal CACC control variables. A lack of consensus has led to significantly different testing conditions even where researchers use the same materials and have similar research objectives. The lack of best practice, particularly with regards to a gas sampling location and the method of GER control, motivates the need for further research so as to improve the value of data collected, reduce uncertainty and optimise CACC reproducibility. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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18. Beyond Mood and Atmosphere: a Conceptual History of the Term Stimmung.
- Author
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Thonhauser, Gerhard
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MOOD (Psychology) ,AESTHETIC experience ,EMPATHY ,PHYSICAL environment ,DISPOSITION (Philosophy) - Abstract
The last few years have seen increasing research interest in moods and atmospheres. While this trend has been accompanied by growing interest in the history of the word Stimmung in other disciplines, this has not yet been the case within philosophy. Against this background, this paper offers a conceptual history of the word Stimmung, focusing on the period from Kant to Heidegger, as this period is, presumably, less known to researchers working with notions like mood, attunement or atmosphere today. Thus, considering this period might provide conceptual resources not yet considered in current debate. Stimmung has the remarkable feature of encompassing the entire semantic field of mood and atmosphere, insofar as both subjects and objects can literally be in Stimmung. Stimmung might refer to the state or condition of being attuned, which is understood as a dispositional state, as well as the process or act of attuning, which includes self-activating and foreign-determined forms of attuning. The word was first used for the tuning of musical instruments, but was quickly transferred to the fields of aesthetics, psychology, and physiology. This paper will focus on the contrast between the psychological canonization of Stimmung as a type of mental state, and the use of Stimmung as an untranslatable, irreducible metaphor with unique semantic force allowing for original theorizing. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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19. Effects of grid spacing on high-frequency precipitation variance in coupled high-resolution global ocean–atmosphere models.
- Author
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Light, Charles X., Arbic, Brian K., Martin, Paige E., Brodeau, Laurent, Farrar, J. Thomas, Griffies, Stephen M., Kirtman, Ben P., Laurindo, Lucas C., Menemenlis, Dimitris, Molod, Andrea, Nelson, Arin D., Nyadjro, Ebenezer, O'Rourke, Amanda K., Shriver, Jay F., Siqueira, Leo, Small, R. Justin, and Strobach, Ehud
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RAIN gauges ,ATMOSPHERIC models ,PRECIPITATION gauges ,CUMULATIVE distribution function ,WEATHER forecasting ,ATMOSPHERE - Abstract
High-frequency precipitation variance is calculated in 12 different free-running (non-data-assimilative) coupled high resolution atmosphere–ocean model simulations, an assimilative coupled atmosphere–ocean weather forecast model, and an assimilative reanalysis. The results are compared with results from satellite estimates of precipitation and rain gauge observations. An analysis of irregular sub-daily fluctuations, which was applied by Covey et al. (Geophys Res Lett 45:12514–12522, 2018. https://doi.org/10.1029/2018GL078926) to satellite products and low-resolution climate models, is applied here to rain gauges and higher-resolution models. In contrast to lower-resolution climate simulations, which Covey et al. (2018) found to be lacking with respect to variance in irregular sub-daily fluctuations, the highest-resolution simulations examined here display an irregular sub-daily fluctuation variance that lies closer to that found in satellite products. Most of the simulations used here cannot be analyzed via the Covey et al. (2018) technique, because they do not output precipitation at sub-daily intervals. Thus the remainder of the paper focuses on frequency power spectral density of precipitation and on cumulative distribution functions over time scales (2–100 days) that are still relatively "high-frequency" in the context of climate modeling. Refined atmospheric or oceanic model grid spacing is generally found to increase high-frequency precipitation variance in simulations, approaching the values derived from observations. Mesoscale-eddy-rich ocean simulations significantly increase precipitation variance only when the atmosphere grid spacing is sufficiently fine (< 0.5°). Despite the improvements noted above, all of the simulations examined here suffer from the "drizzle effect", in which precipitation is not temporally intermittent to the extent found in observations. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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20. ELVES Measurements in the "UV Atmosphere" (Mini-EUSO) Experiment Onboard the ISS and Their Reconstruction.
- Author
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Sharakin, S., Barghini, D., Battisti, M., Belov, A., Bertaina, M., Bianciotto, M., Bisconti, F., Blaksley, C., Blin, S., Cambiè, G., Capel, F., Casolino, M., Ebisuzaki, T., Eser, J., Fenu, F., Franceschi, M. A., Golzio, A., Gorodetsky, P., Kajino, F., and Kasuga, H.
- Subjects
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ELECTROMAGNETIC pulses , *ATMOSPHERE , *ELECTROMAGNETIC interactions , *TRANSIENTS (Dynamics) , *IONOSPHERE , *GLOW discharges - Abstract
More than three dozen submillisecond events of ELVES type ("elves"), which are the result of the interaction of the front of an electromagnetic pulse from a lightning discharge and the lower layer of the ionosphere, have been identified in the data of a UV Atmosphere orbital multichannel detector (Mini-EUSO). Each event has a characteristic annular glow pattern and occupies a significant part of the detector's field of view, and the signal in a separate channel has an asymmetric profile with a pronounced peak. The distribution of peak times contains information about both the localization of the discharge and the altitude of the glow. In this paper, we propose a Bayesian (probabilistic) model for reconstructing ELVES events, implemented using probabilistic programming methods in PyMC-5. The capabilities of the model for determining the position of the discharge are shown using the example of several events. Methods for modifying the model to restore the discharge orientation and refine the glow height are outlined. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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21. Identification of nuclear wastage with the help of scintillation detectors.
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Garg, Kajal and Bhatnagar, Sonali
- Subjects
COSMIC ray muons ,COSMIC rays ,MUONS ,SCINTILLATION counters ,RADIOACTIVE wastes ,RADIOACTIVE substances ,ENERGY dissipation ,ATMOSPHERE - Abstract
This paper explains the use of muon tomography in imaging the dry storage container to detect the high radioactive material in it. Cosmic ray muon is a natural source in the Earth's atmosphere and has high penetrating power and large scattering angle for high Z materials. In this paper, we have designed a dry storage container inside which UO 2 rods have been placed and on increasing the number of these rods muon scattering has been observed. We have shown that as the muons entered into the container, it generates a scattering pattern and from that pattern, we can find the existence of any nuclear waste in it accurately without opening it. Some other parameters such as energy loss, radiation length and scattering angle have also been calculated for 3 GeV–10 GeV muon energy. The results for 3 GeV energy has been compared with C Jewett et al and further extrapolated to higher energies. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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22. ExoMars-2022 Mission ODS Instrument: Modeling and Ground Field Measurements.
- Author
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Khorkin, V. S., Fedorova, A. A., Dobrolenskiy, Yu. S., Korablev, O. I., Vyazovetskiy, N. A., Dzyuban, I. A., Sapgir, A. G., Titov, A. Yu., Toledo, D., Pommereau, J.-P., and Rannou, P.
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MARTIAN atmosphere ,MULTIPLE scattering (Physics) ,PLANETARY surfaces ,MEASURING instruments ,OPTICAL sensors ,ATMOSPHERE - Abstract
The paper presents the results of modeling and ground-based field measurements of the ODS (Optical Depth Sensor) instrument, designed to study aerosol in the Martian atmosphere through daily measurements of illumination on the planet's surface. The device was part of the meteo suite located on the landing platform of the ExoMars-2022 mission. The article presents the structure of the instrument, its optical design and the spectral characteristics of two channels. The main elements of the model for calculating the radiation flux measured by the instrument are described depending on the structure of the atmosphere, the aerosol suspended in it, and the daily motion of the Sun. The calculations were carried out in the approximation of a pseudospherical atmosphere, taking into account the multiple scattering of radiation. Using the created model adapted for the Earth's atmosphere, the ODS signal was simulated for two series of ground-based field measurements at different latitudes. The measured daily dependences in comparison with the simulation results make it possible to determine the optical depth with an accuracy of 0.1. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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23. Temperature and Pressure Sensors of the Meteorological Complex for the Study of the Mars's Atmosphere.
- Author
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Lipatov, A. N., Ekonomov, A. P., Makarov, V. S., Lesnykh, V. A., Goretov, V. A., Zakharkin, G. V., Zaitsev, M. A., Khlyustova, L. I., and Antonenko, S. A.
- Subjects
MARTIAN atmosphere ,TEMPERATURE sensors ,PRESSURE sensors ,HEAT flux ,PRESSURE measurement ,WIND speed ,ATMOSPHERE - Abstract
Temperature and pressure sensors, which are part of the ExoMars-2022 landing platform (LP) meteorological complex, are designed to measure the main parameters of the Martian atmosphere: temperature, pressure, and vertical component of wind speed. Temperature and pressure measurements begin during the descent, after the separation of the lower hemisphere, when the height above the surface will be from 2.1 to 8.5 km, depending on the descent trajectory. Above, before opening the parachute, the vertical profile of the atmosphere can be obtained using the accelerometer block, which is also part of the meteorological complex. After landing, a long-term monitoring of the near-surface layer of the atmosphere is carried out. Measurements are taken at different heights from the surface. Taking into account the measurement of the vertical component of the wind after landing, the local surface-to-atmosphere heat flux is calculated. The measurements make it possible to obtain the dynamics of the interaction between the atmosphere and the surface. In the paper we considered the scientific problems solved by the sensors, briefly described the measurement program and described in detail the sensors and their characteristics. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
24. Accelerometers of the Meteorological Complex for the Study of the Upper Atmosphere of Mars.
- Author
-
Lipatov, A. N., Ekonomov, A. P., Makarov, V. S., Lesnykh, V. A., Goretov, V. A., Zakharkin, G. V., Zaitsev, M. A., Khlyustova, L. I., and Antonenko, S. A.
- Subjects
UPPER atmosphere ,MARTIAN atmosphere ,ANGULAR velocity ,ACCELEROMETERS ,GEOPHONE ,ANGULAR acceleration ,ACCELERATION (Mechanics) - Abstract
The accelerometers and the angular velocity sensor, which are part of the meteorological complex of the ExoMars-2022 landing platform (LP), are designed to measure the acceleration during the deceleration of the lander in the Martian atmosphere. Based on the data, the main parameters of the Martian atmosphere are calculated: density, pressure, and temperature. After landing, the sensors are used to determine the acceleration on the surface and vibration effects on the lander of various nature. The sensors are activated prior to entry into the atmosphere and operate during the entire descent until landing. After landing, a long-term monitoring is carried out to identify vibration effects from the atmosphere and the surface. In the paper we consider the scientific problems solved by the sensors, describe the measurement program and consider in detail the design of the sensors and their characteristics. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
25. Approximate Calculation of the Thermal Loss of the Atmosphere of a Hot Exoplanet in a Low Orbit with Taking into Account the Ellipticity.
- Author
-
Simonova, A. A. and Shematovich, V. I.
- Subjects
ORBITS (Astronomy) ,ELLIPTICAL orbits ,MASS loss (Astrophysics) ,EXTRASOLAR planets ,ATMOSPHERE ,NATURAL satellite atmospheres ,PLANETARY atmospheres - Abstract
The paper presents the results of calculations using an approximate approach to estimating the thermal loss of the atmosphere of a hot exoplanet. The objective of simulation was to study a system of a yellow dwarf of the spectral type G with an exoplanet like a hot sub-Neptune or super-Earth. Estimates of the atmospheric loss rate for a hot sub-Neptune in weakly and strongly elliptical orbits are obtained. Calculations have shown that the atmospheric loss averaged over the orbital period of the model hot sub-Neptune varies from g for an orbit with to g for an orbit with , that is, it increases by almost 4.5 times. Moreover, for and the values of are equal to g, g, and g respectively. Using the average atmospheric mass loss per orbit, we can approximately estimate the time of total atmospheric escape of the considered sub-Neptune—at , this time is approximately equal to 0.32 billion years, and at —approximately 0.07 billion years. Accordingly, we can conclude that the initial ellipticity of the hot exoplanet's orbit is an important factor in estimating the loss rate of the primary hydrogen-helium atmosphere for sub-Neptunes and super-Earths. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
26. Numerical Simulation of Material Ejection into the Atmosphere Induced by Oblique Impacts of Ten-Kilometer-Diameter Asteroids into the Ocean.
- Author
-
Shuvalov, V. V.
- Subjects
ASTEROIDS ,SOIL air ,COMPUTER simulation ,WATER masses ,ATMOSPHERE ,CASCADE impactors (Meteorological instruments) - Abstract
Abstract—The results of a three-dimensional numerical simulation of the oblique impacts of ten-kilometer asteroids at an angle of 45° onto a solid surface and into an ocean with a depth of 1 to 6 km are presented. The maximum masses of water, impactor, and soil ejected into the atmosphere and the masses of water, impactor material, and soil remaining in the atmosphere 10 min after the impact are calculated. The mass of vaporized ejecta is determined. It is shown that there are 2–5 times more impactor material and soil ejected into the atmosphere during oblique impacts than during vertical impacts. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
27. Neural Networks for Searching for Meteoral Signals in the Data of the Orbital Telescope "UV Atmosphere".
- Author
-
Zotov, M., Sokolinskii, D., and Arifullin, A.
- Subjects
COSMIC rays ,ATMOSPHERE ,SPACE stations ,METEORS ,RADIATION dosimetry ,ORBITS (Astronomy) - Abstract
Since 2019, the Russian–Italian experiment "UV Atmosphere" (Mini-EUSO) has been operational on the International Space Station. The primary instrument of this experiment is a wide-angle telescope positioned toward nadir. Its main objective is to generate an ultraviolet map of the Earth's nocturnal atmosphere radiation. This map serves as a crucial element in the preparation of a large-scale experiment involving the study of extremely high-energy cosmic rays using an orbiting telescope. Similar to the preceding TUS experiment, the "UV Atmosphere" instrument detects signals from various atmospheric processes in the ultraviolet range, including the luminosity of meteors. In this paper, we describe two simple neural networks that effectively extract meteor signals from the overall data stream. The proposed approach can also be applied to identify track-like signals of various origins in the data obtained from fluorescent and Cherenkov telescopes. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
28. On the Possibility of Multichannel Optical Backscattering Sondes for Joint Balloon and Lidar Studies of the Aerosol Composition of the Middle Atmosphere.
- Author
-
Balugin, N. V., Fomin, B. A., Yushkov, V. A., Marichev, V. N., and Bochkovskyi, D. A.
- Subjects
- *
TROPOSPHERIC aerosols , *MIDDLE atmosphere , *AEROSOLS , *STRATOSPHERIC aerosols , *ATMOSPHERIC temperature measurements , *LIDAR - Abstract
In the practice of aerological sounding, along with lidar observations, aerosol backscattering sondes are used at night to study and monitor polar stratospheric clouds, tropospheric and stratospheric aerosol, cirrus clouds, pyroconvection, and volcanic aerosol, as well as to verify remote methods and means of ground-based and satellite-based aerosol observations. For aerosol sondes, a simple two-wave measurement technique is used, which makes it possible to diagnose changes in aerosol composition by color index. There are limitations to the possibilities of the two-wave technique, and they are discussed in this article. Aerological sounding combined with lidar observations expands the wavelength range for multiwavelength studies, and direct measurements of atmospheric temperature increase the accuracy of aerosol sensing. This paper considers the application of three or more wavelength techniques. Data from probe measurements using wavelengths of 470, 528, 850, and 940 nm and lidar sensing at wavelengths of 355 and 532 nm are presented. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Intricacies Unveiled: A Review Bridging Gaps in Aerosol-Lightning Dynamics for a Holistic Perspective.
- Author
-
Firoozjaee, Fatemeh Rahmani, Gautam, Sneha, and Samuel, Cyril
- Abstract
Aerosols have consistently held a prominent position within the academic sphere, driving a substantial body of research in this field. The main goal of this study is to thoroughly examine the body of scientific literature concerning aerosols and lightning using rigorous scientific methods. To achieve this goal, we've conducted a detailed bibliometric analysis to systematically evaluate and clarify the performance metrics of the relevant scholarly publications. Our efforts have allowed us to discover and define three main areas of research: Lightning and Environment, Pollution, and Effects on Nature and Characteristics of Aerosols. Based on our analyses, we've discovered three significant gaps in current knowledge: (i) Understanding how aerosols affect cloud formation and precipitation, revealing their complex interactions. (ii) Investigating how aerosols impact lightning generation and behavior. (iii) Examining the health implications of aerosols in the atmosphere. This research delves into the interplay between aerosols and lightning, examining a vast collection of up to 1000 papers across 819 journals. It examines 100 author keywords pertaining to prominent works, along with 470 keywords associated with three major clusters within the research domain. Data collection spans from 1970 to May 2023, leveraging a comprehensive database. This analysis provides a fresh perspective by comparing the latest studies with their predecessors, enriching our scientific comprehension of this relationship. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Parameterization of the Interaction between the Atmosphere and the Urban Surface: Current State and Prospects.
- Author
-
Tarasova, M. A., Varentsov, M. I., and Stepanenko, V. M.
- Subjects
SURFACE states ,URBAN heat islands ,URBAN plants ,PARAMETERIZATION ,BUILDING additions ,EDDY flux ,ATMOSPHERE - Abstract
Cities have a significant impact on the environment, forming microclimatic features such as urban heat island, an increase in the intensity of convective weather events, etc. Numerical models of the atmosphere with an integrated block that describes the interaction between the urbanized surface and the atmosphere—urban parameterization—are good at reproducing the meteorological features of the urban environment. Reviews of urban parameterizations are mostly outdated, and recent ones do not fully cover aspects of the methods used in the models to describe physical processes. This paper is dedicated to updating information on urban parameterizations, comparing the approaches used in them to describe physical processes, and forming proposals for their improvement. Based on the most common urban parameterizations of various levels of complexity, the main groups of physical processes describing "urban surface-atmosphere" interaction are identified. They are the surface energy balance, radiation heat transfer, surface moisture balance, turbulent heat and moisture exchange in the urban canopy, anthropogenic influence on heat and moisture fluxes, radiation, and turbulent interaction with urban vegetation. The main approaches to the parameterization of physical processes are defined within each block. Modern trends in the development of urban parameterizations are highlighted: (1) over the past 10 years, parameterizations have become more complicated due to the addition of the building energy model, a three-dimensional structure of urban vegetation, and vertical resolution when calculating turbulent fluxes; (2) at the same time, not much attention is paid to revising the original empirical formulas, often obtained on the basis of single field or laboratory experiments. Ways to improve urban parameterizations are proposed by clarifying the basic dependencies used mainly in the calculation of turbulent fluxes, particularly using the results of highly detailed large-eddy simulation modeling, which, with growing computational power, is increasingly used to simulate explicit heat transfer between the atmosphere and individual elements of the urban environment. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
31. Recent observations and research progresses of terrestrial gamma-ray flashes during thunderstorms.
- Author
-
Lyu, Fanchao, Zhang, Yijun, Lu, Gaopeng, Zhu, Baoyou, Zhang, Hongbo, Xu, Wei, Xiong, Shaolin, and Lyu, Weitao
- Subjects
THUNDERSTORMS ,ATMOSPHERIC electricity ,PHOTON detectors ,LIGHTNING ,SPATIAL resolution ,ATMOSPHERE - Abstract
Terrestrial gamma-ray flashes (TGFs) are high-energy emissions in thunderstorms that were discovered first by satellite-based and then by ground-based gamma-ray detectors with photon energy up to tens of MeV. TGFs are a natural high-energy phenomenon associated with lightning discharges that frequently occur during thunderstorms. However, their production mechanisms and associated processes are still unclear. TGF studies have already been a research spotlight in the atmospheric electricity and high-energy atmosphere research areas. In this paper, we review recent research progresses on TGF studies in the past decade, including TGF detection, the relationship between TGFs and lightning processes, and thunderstorm activities. Several unsolved important scientific questions are discussed. Results suggest that upward TGFs observed by satellite-based detectors are closely connected with the development of in-cloud upward negative leaders. They are usually generated in milliseconds of the initiation of upward negative leaders and may produce a kind of distinct radio emissions because of the generation and propagation of huge amounts of high-energy electrons. By contrast, its counterpart, i.e., downward TGFs observed by ground-based gamma-ray detectors, is associated with different types of lightning processes, such as downward negative or upward positive leaders, the initial continuing current stage of rocket-triggered lightning flashes return stroke processes. Because of limited observations, how these downward TGFs are generated is still unclear. Benefiting from the development of state-of-the-art instruments with high temporal and spatial resolutions, new insights into the processes and mechanisms of TGFs will be achieved with coordinated observations from satellite-based and ground-based measurements. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. The Möbius strip of market spatiality: mobilizing transdisciplinary dialogues between CCT and the marketing mainstream.
- Author
-
Coffin, Jack and Chatzidakis, Andreas
- Abstract
This paper develops the Möbius strip as an 'ordering theory' (Sandberg and Alvesson, 2020) that brings CCT studies into dialogue with mainstream marketing approaches. The aim is to work toward a transdisciplinary understanding of market spatiality, a topic that has become increasingly important for theorists and practitioners (Warnaby and Medway, 2013; Castilhos et al., 2016; Chatzidakis et al., 2018). Building on psychosocial interpretations of the Möbius strip as a 'tactical' way of thinking, a range of insights and ideas are organized along a single strip of theorization. This paper maps a continuous plane of logic between the concepts of space, place, emplacement, spatiality, implacement, and displacement. The potential applications of the Möbius strip are then demonstrated by showing how the transdisciplinary topic of 'atmosphere' can be theorized from multiple perspectives. The paper concludes by exploring how the Möbius strip might also be employed in other areas of marketing theory and practice, potentially generating further transdisciplinary conversations between CCT and the marketing mainstream. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
33. Structure and properties of 0.5Bi4Ti3O12-0.5BiFe0.98Mn0.02O3 films under different annealing atmospheres.
- Author
-
Liu, Yan, Wang, Yangyang, Wang, Guodong, Yao, Bingdong, He, Jingxian, Zhang, Fengqing, and Li, Jing
- Subjects
X-ray photoelectron spectroscopy ,FERROELECTRIC materials ,BAND gaps ,ATMOSPHERE ,STRAY currents - Abstract
In this paper, 0.5Bi
4 Ti3 O12 –0.5BiFe0.98 Mn0.02 O3 (BTBF) films were prepared on FTO/glass substrates using the sol-gel method. The impacts of BTBF films on the grain structure, defect density, electrical properties and ageing properties were studied under air, oxygen and nitrogen-annealing atmospheres. X-ray diffraction (XRD) results demonstrate that the ferroelectric materials formed by the combination of Bi4 Ti3 O12 (BIT) and BiFe0.98 Mn0.02 O3 (BFMO) in the form of a solid solution show a bismuth-layered perovskite structure. X-ray photoelectron spectroscopy (XPS) shows that samples annealed under an O2 atmosphere have higher Fe3+ : Fe2+ ratios and fewer oxygen vacancy defects. Meanwhile, the samples annealed under an O2 atmosphere show better ferroelectric properties (2Pr ≈ 22.0 µC/cm2 ) and a lower leakage current density (J ≈ 7.09 × 10− 6 A/cm2 ). In addition, the annealing atmosphere is also found to affect the light absorption performance of the samples, and the samples annealed under a N2 atmosphere show a smaller band gap and better light absorption performance. Finally, the ageing phenomenon for the samples is analysed, and the volumetric effect ageing mechanism is discussed. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
34. On the Theory of Individual Atmospheric Vortices: An Example of the Subtropical Anticyclone Evolution.
- Author
-
Kislov, A. V., Zheleznova, I. V., Mukhartova, Yu. V., and Nesviatipaska, A. I.
- Subjects
WHIRLWINDS ,ATMOSPHERIC physics ,ORDINARY differential equations ,ATMOSPHERE ,ORTHOGONAL functions - Abstract
The physics of individual atmospheric vortices is far from clear, despite the fact that modern hydrodynamic models reliably reproduce them. In this paper, we develop the theory of vortices that stably exist for a long time in a certain region. Their structure is characterized by the first (dominant) empirical orthogonal function (EOF), and the dynamics is determined by the coefficient at a given mode y
1 (t), for which an ordinary differential equation is obtained based on the vorticity budget equation. The residual between the explicitly resolved terms is compensated by the parameterization, which is based on taking into account the effects of the second and subsequent modes of the EOF expansion. It is shown that it consists of Gaussian noise and a nonrandom component, which can be approximated using a cubic function of y1 (t). To test the developed technique, we used modeling of the vorticity behavior describing the dynamics of the most stable vortex in the Earth's atmosphere—the subtropical (Hawaiian) anticyclone. ERA5 reanalysis data were used for the work. The proposed approach to the analysis of integral vortex structures is supposed to be used to evaluate various circulation systems, identify factors affecting their dynamics in different regions, and study extreme hydrometeorological events associated with long-lived vortices. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
35. On the Possibility of Observing Nitric Oxide on Terrestrial Exoplanets Using the WSO-UV Observatory.
- Author
-
Tsurikov, G. N. and Bisikalo, D. V.
- Subjects
NITRIC oxide ,OBSERVATORIES ,SPACE telescopes ,ATMOSPHERE ,ARTIFICIAL satellites ,EXTRASOLAR planets - Abstract
It is generally believed that the presence of a -dominant atmosphere is an indication of biological and geological activity on terrestrial exoplanets that are in the habitable region. One of indicators of such an atmosphere is the nitric oxide (NO) molecule. It is known from satellite observations of the Earth's atmosphere that the brightest nitric oxide band in the ultraviolet range is the band (203–248 nm). Space telescopes such as the existing HST and the upcoming WSO-UV can observe in this spectral range. The paper presents estimates of the luminosity of various exoplanets in the NO band. It has been established that the detection of NO emission in the γ band in the atmospheres of typical terrestrial exoplanets is possible using the spectrographs of the WSO-UV observatory within a reasonable observational time (5 WSO-UV orbits or 120 observation hours). [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. Vortex carrying circular airy beam in free space optics and aberration effects in turbulent atmosphere.
- Author
-
Lazer, Nimmy, Teen, Y. P. Arul, and Rajesh, K. B.
- Subjects
FREE-space optical technology ,OPTICAL aberrations ,ASTIGMATISM (Optics) ,ATMOSPHERE ,INTEGRAL equations ,WEATHER ,NUMERICAL analysis - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
37. Cold Spot over the Lofoten Vortex.
- Author
-
Travkin, V. S., Belonenko, T. V., and Kubryakov, A. A.
- Subjects
ADVECTION ,OCEAN ,ATMOSPHERE ,MAPS ,NORWEGIANS - Abstract
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]
- Published
- 2022
- Full Text
- View/download PDF
38. Reconstructions of the Heliospheric Modulation Potential and Earth Climate Variations over the Past 20 000 Years.
- Author
-
Kudryavtsev, I. V., Dergachev, V. A., and Nagovitsyn, Yu. A.
- Subjects
CLIMATE change ,SOLAR activity ,GLACIAL Epoch ,SOLAR oscillations ,CARBON dioxide ,ATMOSPHERE - Abstract
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]
- Published
- 2022
- Full Text
- View/download PDF
39. Atmospheric Vortex Excited by a Gasdynamic Instability.
- Author
-
Shkadov, V. Ya. and Beloglazkin, A. N.
- Abstract
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]
- Published
- 2022
- Full Text
- View/download PDF
40. Analytical Approximations of the Characteristics of Nighttime Hydroxyl on Mars and Intra-Annual Variations.
- Author
-
Shaposhnikov, D. S., Grygalashvyly, M., Medvedev, A. S., Sonnemann, G. R., and Hartogh, P.
- Subjects
GENERAL circulation model ,MARTIAN atmosphere ,MARS (Planet) ,ATMOSPHERIC circulation ,ATMOSPHERIC composition - Abstract
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 × 10
4 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]- Published
- 2022
- Full Text
- View/download PDF
41. Dilution of concentrations of PAHs from atmospheric particles, bulk deposition to soil: a review.
- Author
-
Liu, Jialin, Jia, Jianli, and Grathwohl, Peter
- Subjects
POLYCYCLIC aromatic hydrocarbons ,ATMOSPHERIC deposition ,SOIL air ,PUBLIC spaces ,DISEASE risk factors - Abstract
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]- Published
- 2022
- Full Text
- View/download PDF
42. Analysis of Seasonal Signal in GPS Short-Baseline Time Series.
- Author
-
Wang, Kaihua, Jiang, Weiping, Chen, Hua, An, Xiangdong, Zhou, Xiaohui, Yuan, Peng, and Chen, Qusen
- Subjects
TROPOSPHERE ,GLOBAL Positioning System ,ATMOSPHERE ,ARTIFICIAL satellites in navigation ,TIME series analysis - Abstract
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]
- Published
- 2018
- Full Text
- View/download PDF
43. Multidimensional analysis of global climate change: a review.
- Author
-
Bandh, Suhaib A., Shafi, Sana, Peerzada, Mohazeb, Rehman, Tanzeela, Bashir, Shahnaz, Wani, Shahid A., and Dar, Rubiya
- Subjects
CLIMATE change ,CLIMATE change mitigation ,GLOBAL analysis (Mathematics) ,ATMOSPHERE ,HUMAN migrations ,PHENOMENOLOGICAL theory (Physics) - Abstract
Even though climate change involves much more than warming, it is the name given to a set of physical phenomena. It is a long-term change in weather patterns that characterises different regions of the world. The warming effect in the earth's atmosphere has dramatically increased through the influence of some heat-taping gases emitted by various human activities, especially fossil fuel burning. The more the input of such gases, the more will be the warming effect in the coming times. Global climate change is already visible in various parts of the larger ecosystems like forests, fisheries, biodiversity, and agriculture; however, it is now also influencing the supply of freshwater, human health, and well-being. This paper reviews climate change drivers, its global scenario, major global events, and assessing climate change impacts. The most daunting problem of economic and ecological risks, along with the threats to humanity, is also discussed. The paper further reviews the species' vulnerability to climate change and the heat waves and human migration vis-à-vis climate change. Climate change politics and coverage of climate change episodes in mass media is the special focus of this review that concludes with a few mitigation measures. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
44. Thermal Analysis of Trajectories of Return from the Moon Using Several Entries into the Atmosphere for Ballistic Capsule and Gliding Descent Vehicles.
- Author
-
Leonov, V. V., Grishko, D. A., Airapetyan, M. A., Shvyrkina, O. S., and Nikitin, G. A.
- Subjects
THERMAL analysis ,GLIDING & soaring ,SPACE trajectories ,ATMOSPHERE ,MOON ,SAFETY factor in engineering ,VEHICLES - Abstract
In this paper, we study the scheme of a descent vehicle's return from the Moon using several intermediate passages of the Earth's atmosphere before landing. The features of the behavior of these trajectories near the Earth are shown for a ballistic capsule and gliding descent vehicles with low aerodynamic quality (0.3–0.5). Using the atmosphere as a natural braking method reduces inertial and thermal loads in comparison with direct entry at near-parabolic velocity. However, a decrease in the magnitude of loads is accompanied by an increase in the duration of their impact. Even in the case of one intermediate passage of the atmosphere, this leads to the burnout of a noticeably larger (compared to direct entry) mass of the heat-protective coating, which is a key factor in ensuring the safety of the descent. This paper shows that the use of trajectories with one intermediate passage of the atmosphere makes it possible to change the nature of the carryover of a heat-protective coating consisting of a filler and binder. For direct entry with a near-parabolic velocity, the destruction of the filler occurs accompanied by a change in the shape of the vehicle. When using the scheme with preliminary atmospheric braking, the bulk of the carried away matter falls on the binder, which brings the descent mode closer to the repeatedly worked out in practice descent from low near-Earth orbit. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
45. An Investigation of the Influence of Seasonal and Latitudinal Variations of Atomic Oxygen on the Intensity of Self-Emission of the Night Atmospheres of the Earth and Mars.
- Author
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Antonenko, O. V. and Kirillov, A. S.
- Subjects
- *
MARTIAN atmosphere , *ATMOSPHERIC oxygen , *UPPER atmosphere , *AUTUMNAL equinox , *ATMOSPHERE , *SOLAR activity , *OXYGEN - Abstract
Experimental data on the characteristic concentrations of atomic oxygen in the upper atmospheres of the Earth and Mars are considered in the paper. The values of the integrated intensities of Herzberg I bands for the middle latitudes and the equatorial zone of the Earth are calculated, as well as for the northern latitudes and the equatorial zone of Mars. The correlation of theoretically calculated results for the emission intensities of the bands of electronically excited molecular oxygen in the Earth's atmosphere in the spectral range of 250–370 nm and of experimental data on the glow of molecular oxygen obtained from the Discovery cosmic shuttle (STS-53) is discussed. The calculated values of the column integrated intensities of the Herzberg I band system in the Earth's atmosphere for various seasons and for points of the equinox of Mars are presented. It is shown that at the middle latitudes of the Earth during the period of low solar activity, the maximum values of integral intensities are typical for July, but in the equatorial zone they are typical for April. In the northern latitudes of Mars, the maximum values occur at the moment of the autumn equinox. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. An Analysis of Atmospheric Aerosol Characteristics Using Remote Sensing Data in the Indian Region.
- Author
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Anitha, M. and Kumar, Lakshmi Sutha
- Subjects
- *
ATMOSPHERIC aerosols , *MODIS (Spectroradiometer) , *AEROSOL analysis , *REMOTE sensing , *AIR quality , *ATMOSPHERE - Abstract
The aerosols present in the atmosphere are considered to be an essential element that directly affects the cloud properties, radiation budget of Earth, human health, and quality of air. Therefore, it is mandatory to investigate aerosol concentration and properties both in the local and global regions while studying global climate change. In this paper, an analysis of aerosol properties such as single scattering albedo (SSA), aerosol optical depth (AOD) at 500 nm, angstrom exponent (AE) (440–870 nm), and aerosol volume size distribution (VSD), which are retrieved from relatively long term AErosol RObotic NETwork (AERONET) at Karunya University, Kanpur, Gandhi College, Pune, and Jaipur is made for the years from 2010 to 2019. The comparisons of the parameters based on wavelength and seasons for the five places considered are provided. The result analysis shows that the indo gangetic plain (IGP) region places such as Gandhi College and Kanpur experience larger AOD values during the 10-year period considered as compared to other sites. The seasonal analysis of AE, SSA, and VSD reveals that the dominance of fine particles is available mainly in post-monsoon and winter season except Jaipur, whereas coarse particles always occurred in monsoon and pre-monsoon seasons at all the places except Karunya University. The comparison between the AODs retrieved from the MODIS (Moderate Resolution Imaging Spectroradiometer) satellite and AERONET is also provided. The comparison shows that 50% and 43.48% of MODIS-derived AOD match well with the AERONET-derived AOD within the expected error values for Gandhi College and Kanpur, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Propagation of Acoustic-Gravity Waves in Inhomogeneous Wind Flows of the Polar Atmosphere.
- Author
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Fedorenko, A. K., Kryuchkov, E. I., Cheremnykh, O. K., and Melnychuk, S. V.
- Subjects
- *
THEORY of wave motion , *WIND speed , *ATMOSPHERIC acoustics , *ATMOSPHERE , *INHOMOGENEOUS materials - Abstract
The satellite observations of acoustic-gravity waves (AGW) in the polar atmosphere regions indicate that these waves are closely related with wind flows. This paper deals with the specific features of the propagation of acoustic-gravity waves in spatially inhomogeneous wind flows, wherein the velocity is slowly changed in the horizontal direction. A system of hydrodynamic equations taking into account the wind flow with spatial inhomogeneity is used for analysis. Unlike the system of equations written for a stationary medium (or a medium moving at a uniform velocity), the derived system contains the components describing the interaction of waves with a medium. It is shown that the effect of inhomogeneous background medium parameters can be separated from the effects of inertial forces by a special substitution of variables. An analytical expression describing the change in the amplitude of waves in a medium moving at a nonuniform velocity is derived. This expression contains two functional dependences: (1) the linear part, which is caused by the changes in the background parameters of a medium and independent of the propagation direction of waves with respect to the flow, and (2) the exponential part, which is related with inertial forces and characterizes the dependence of the amplitudes of acoustic-gravity waves on the direction of their propagation. The exponential part shows an increase in the amplitudes of waves in the headwind and a decrease in their amplitudes in the downwind. The derived theoretical dependence of the amplitudes of acoustic-gravity waves on the wind velocity is in good agreement with the data of the satellite observations of these waves in the polar atmosphere. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Comparison of Line-of-Sight Magnetic Field Observed by ASO-S/FMG, SDO/HMI and HSOS/SMAT.
- Author
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Xu, Haiqing, Su, Jiangtao, Liu, Suo, Deng, Yuanyong, Yang, Shangbin, Bai, Xianyong, Chen, Jie, Wang, Xiaofan, Yang, Xiao, Song, Yongliang, and Idrees, Shahid
- Subjects
- *
MAGNETIC fields , *SOLAR magnetic fields , *SOLAR activity , *SOLAR telescopes , *ATMOSPHERE - Abstract
The Full-disk MagnetoGraph (FMG) onboard the Advanced Space based Solar Observatory has obtained a series of line-of-sight magnetic-field measurements since its launch in October 2022. It is important to compare its observational data with other existing solar telescopes. In this paper, we make a detailed comparison of four active regions and a pore region simultaneously observed by FMG, the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamic Observatory, and the Solar Magnetism and Activity Telescope (SMAT) at Huairou Solar Observing Station. We find that the magnetic-field structure and spatial distribution are basically consistent among these three instruments. The initial correlation coefficient of magnetic field is approximately 0.90. The coefficient slightly increases when sunspot umbra regions are excluded, and it increases significantly up to 0.98 for the magnetic field in penumbra regions. The magnetic field observed by FMG tends to be weaker than the HMI in strength in sunspot umbra due to saturation effect, whereas larger outside sunspot. The differences are probably due to different noise levels, seeing conditions (SMAT is affected by the Earth's atmosphere) and observational and calibration methods. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Turbulent Exchange in Unsteady Air–Sea Interaction at Small and Submesoscales.
- Author
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Chukharev, A. M. and Pavlov, M. I.
- Subjects
- *
WIND speed , *OCEAN-atmosphere interaction , *OCEANOGRAPHY , *PHYSICAL constants , *ATMOSPHERE - Abstract
An adequate description of the interaction between the atmosphere and ocean remains one of the most important problems of modern oceanology and climatology. The extremely wide variety of physical processes occurring in the coupled layers, large range of scales, and moving boundary all significantly complicate the creation of models that would allow calculating the physical characteristics in both media with the necessary accuracy. In this paper the temporal variability of dynamic parameters in the driving layer of the atmosphere and in the near-surface layer of the sea on small and submesoscales from one to several tens of hours is considered. The experimental data show a very high correlation between the friction wind velocity and turbulence intensity in the upper sea layer on all scales recorded. One important distinguishing feature of all measured physical quantities in both media is the presence of quasi-periodic oscillations with different periods. For a more accurate description of momentum and energy fluxes from the atmosphere, a nonstationary model of turbulent exchange in the near-surface layer of the sea is proposed. It takes into account quasi-periodicity in the intensity of dynamic interaction between the atmosphere and the sea at these scales. In the model we use the equations of momentum and turbulent energy balance, the system of equations is solved numerically, and the calculation results are compared with other models and with experimental data. It is shown that taking into account the nonstationarity of the wind strain improves the correspondence between the calculations and the experimental data. It is noted that, in the nonstationary case, the energy and momentum flux from the atmosphere and the turbulence intensity increases compared to the action of a constant average wind of the same duration. Therefore, the strong averaging often used in global models may markedly underestimate the intensity of the dynamic interaction between the atmosphere and ocean. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Axial intensity of Bessel higher-order cosh-Gaussian beam propagating in a turbulent atmosphere.
- Author
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Dalil-Essakali, L., Nossir, N., and Belafhal, A.
- Subjects
- *
ATMOSPHERIC turbulence , *METEOROLOGICAL optics , *FREE-space optical technology , *ATMOSPHERE , *LASER beams - Abstract
In the present paper, the effects of the turbulent atmosphere on the propagation properties of Bessel higher-order cosh-Gaussian (BHChG) beam are investigated. Based on the Rytov approximation and the extended Huygens–Fresnel integral diffraction, analytical expression of the axial intensity for BHChG beam is evaluated and the results of some laser beams are deduced as particular cases from our research. Some graphical representations have been carried out to study the influence of the incident beam parameters and the atmospheric turbulence on the considered beam. The obtained results can be useful for atmospheric optics applications in free-space optical communications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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