Cosmic Research最新文献

{"title":"Analysis of the Impact of Species Composition, Projective Cover, and Phytomass of Vegetation in Arid Pasture Landscapes on Their Spectral Reflectance Properties Based on Ground Measurements","authors":"S. S. Shinkarenko, S. A. Bartalev","doi":"10.1134/s0010952523700703","DOIUrl":"https://doi.org/10.1134/s0010952523700703","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The intensification of pasture degradation in the southern part of European Russia, which is caused by unfavorable hydrothermal conditions and unregulated livestock numbers, requires the development of approaches to assess the capacity of forage lands using Earth remote sensing methods. The spectral reflectance properties of vegetation are determined by its taxonomic, structural, phenological, biophysical, and biochemical characteristics. However, the patterns of how these parameters affect the spectral response are region-specific and heavily influenced by soil cover. Therefore, it is essential to expand the regional scope of studies on the spectral reflectance properties of various vegetation types. This research is devoted to determining the spectral reflectance properties of natural zonal pastures in southern European Russia, based on geobotanical investigations and field spectrometry using the PSR-1100f instrument within the 320–1100 nm range. Groundwork was carried out in May (the period of maximum green mass of vegetation) 2020–2022 in the territories of natural zonal pastures in Astrakhan and Volgograd oblasts, Stavropol krai, and the Republics of Dagestan and Kalmykia. Significant differences were found between feather grasses, semishrubs, and annuals in the visible and near-ultraviolet spectral regions. Changes in the projective cover, under other equal conditions, have the most significant impact on spectral properties in the 660–670 nm range, which is consistent with the results of other researchers. Vegetation indices were identified that are best suited for determining projective cover and above-ground biomass of pastures with various dominant species. Further research will enable transitioning from point measurements of spectral reflectance and structural vegetation characteristics to satellite data with different spatial resolutions.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140888725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of the Index Paradigm in Remote Sensing of Soil Cover","authors":"I. M. Mikhailenko, V. N. Timoshin","doi":"10.1134/s0010952523700624","DOIUrl":"https://doi.org/10.1134/s0010952523700624","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The aim of the work is the systematic analysis and generalization of the conventional index paradigm of using Earth remote sensing data to assess the state of the soil and vegetation cover. It has been established that the scalar form and the lack of a mathematical basis do not allow the use of conventional vegetation and the similar indices for evaluating the vectors of quantitative indicators of the soil and vegetation cover. At the same time, for making many types of management decisions in agriculture, it is important to construct index images that reflect such qualitative indicators as types of cultivated and weed plants, the presence of plant diseases, damage of crops and soils, and physical and chemical stresses. In terms of informational content, the evaluation of such qualitative states is a procedure for recognizing patterns or classes of soil-and-vegetation complex objects. The subjective empirical approach in choosing the spectral composition of the indices of their combinations, which is currently used, does not currently allow sufficient reliability of such procedures. Therefore, the purpose of the study present is to formalize the process, which enables the empirical approach of constructing indices to be excluded and the entire procedure for their formation for any number and types of recognizable objects to be automated. The basis of formalization is the algorithms for evaluating and selecting the information content of features, followed by the construction of index models, which are linear decision rules for class recognition. The attributes of the classes are the spectral subranges into which the entire spectrum of remote sensing data is divided. The number of informative features is selected from the condition for ensuring the required reliability of recognition of all observed objects (classes).</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140888737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring Nitrogen Dioxide Content in the Atmosphere of Cities in Europe and Russia Using Satellite Data","authors":"A. A. Tronin, M. S. Sedeeva, G. M. Nerobelov, M. P. Vasiliev","doi":"10.1134/s0010952523700739","DOIUrl":"https://doi.org/10.1134/s0010952523700739","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>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.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139979914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of Northern Burnt Forest Mortality in the 21st Century Based on MODIS Data on Fire Intensity","authors":"D. V. Lozin, E. A. Loupian, I. V. Balashov, S. A. Bartalev","doi":"10.1134/s0010952523700600","DOIUrl":"https://doi.org/10.1134/s0010952523700600","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper presents estimates of forest mortality from fires that occurred in the northern territories in the 21st century, based on the analysis of fire burning intensity obtained from MODIS instruments installed on satellites <i>Terra</i> and <i>Aqua</i>. A brief analysis of fire distribution and forest mortality resulting therefrom is also presented in the paper both by year and by different territories (countries). The analysis shows that from 2002 to 2021, 70 659 fires were registered in Zone 60 (the area north of 60° N) and 5997 fires were registered in Zone AC (the area north of the Arctic Circle). Moreover, 33 892 fires in Zone 60 were registered from 2002 to 2011 and 36 767 fires from 2012 to 2021; 2395 fires were registered in Zone AC from 2001 to 2011 and 3602 fires from 2012 to 2021. Between 2002 and 2021, 102 million ha of forest land were covered by fires in Zone 60 and 8 million ha in Zone AC. At the same time, more than 22 million ha of forests died in Zone 60 (they received the fifth grade of the average weighted category state in the final fire year), and over 2 million ha died in Zone AC. Over 2002–2011, 7 015 000 ha of forests died in Zone 60 (1.2 % of all forest vegetation in the zone; an average of 19.6% of the area affected by fire) and 15 372 000 ha of forests over 2012–2021 (2.6 and 23.3%, respectively); over 2002–2011, 641 thousand ha of forests died in Zone AC (2.8 and 23.7%, respectively) and 1 379 000 ha of forests over 2012–2021 (1.9 and 26.5%, respectively). The paper also presents information on forest death by territories (countries) in the analyzed zones. The presented data made it possible to draw the following preliminary conclusions: over recent decades, there have been no significant changes in the number of fires in Zone 60. Nevertheless, it is worth noting that, in 2019–2020, the number of fires in Zone AC increased drastically in Russia; in the second decade of the analyzed period, an increase in forest death from fires in the analyzed zones in Russia was observed; over the study period, no trends were observed in the ratio of the area of dead forests and total forest area in the analyzed countries; the average percentage of dead forests for the entire study period is comparable in Russia, the United States, and Canada, though it is significantly lower in Northern European countries; the same picture is observed in the ratio of dead forest area and fire affected area.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139980024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Analytical Method for Determining the Conditions of Long-Term Orbital Existence of Technogenic Nanoparticles Injected into Near-Earth Space in a High Circular Orbit","authors":"","doi":"10.1134/s0010952523700806","DOIUrl":"https://doi.org/10.1134/s0010952523700806","url":null,"abstract":"<span> <h3>Abstract</h3> <p>The paper analytically determines, based on the use of “drift” equations of motion, the conditions for the implementation of two possible modes of long-term orbital existence of technogenic nanoparticles injected into near-Earth space in a high circular orbit in the ring current region and not going beyond this region during orbital motion. It is shown that, in each of these modes, the leading center of the nanoparticle, without reaching the dense layers of the atmosphere, in the leading plane periodically oscillates along the segment of the geomagnetic field line between the “mirror points,” which, in one mode, are located in the northern and southern hemispheres, and, in the other, in the same hemisphere as the point injection. The correctness of the formulated conditions is confirmed by comparison with the results of the corresponding numerical experiments.</p> </span>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140071590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subterahertz Astronomy in the Russian Federation: Prospects and Directions","authors":"","doi":"10.1134/s0010952523700764","DOIUrl":"https://doi.org/10.1134/s0010952523700764","url":null,"abstract":"<span> <h3>Abstract</h3> <p>This paper addresses the scientific and technical prospects and potential directions for the development of subterahertz astronomy in the Russian Federation. The concept of creating subterahertz instruments in the form of a universal compact antenna array for placement on the territory of the Russian Federation is proposed. It is possible to implement several space projects in the subterahertz range using such an antenna array, including a space interferometer and a telescope on the surface of the Moon. Ground-based compact antenna arrays will be able to act as a support for the very long baseline interferometer mode of the <em>Millimetron</em> observatory.</p> </span>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140076413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-Dimensional Structure and Dynamics of Coastal Eddy Dipoles in the Southeastern Baltic Sea: Results of Remote Sensing and Oceanographic Experiments in Summer 2021","authors":"","doi":"10.1134/s0010952523700582","DOIUrl":"https://doi.org/10.1134/s0010952523700582","url":null,"abstract":"<span> <h3>Abstract</h3> <p>The results of quasi-synchronous satellite and experimental field observations of two submesoscale eddy dipoles in the coastal zone of the southeastern Baltic Sea near the coast of Kaliningrad Region are presented. The parameters of eddy dipole dynamics, namely, the duration of the process in the sea water and its propagation velocity and direction, as well as atmospheric conditions favorable for the occurrence of eddy dipoles, are determined from consecutive satellite images of high resolution. The characteristics of the three-dimensional structure of eddy dipoles are determined using the data of an acoustic current profiler and a hydrological probe obtained concurrently with satellite survey. The depth of vortical motion penetration into the water column is discussed and it is shown that such processes are not purely surface phenomena but have their influence down to a depth of 20 m and more. Direct measurements of current velocities and directions within particular parts of an eddy dipole demonstrate significantly greater dynamics of waters inside such formations compared to their displacement velocity. The differences in the anticyclonic and cyclonic parts of the dipoles are evaluated. Hydrological observations show the influence of the active cyclonic part of a dipole on surrounding waters manifested in both capture (rise) of deeper water and accumulation of surfactants within it.</p> </span>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139980038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automation of Surface Karst Assessment Using Sentinel‑2 Satellite Imagery","authors":"","doi":"10.1134/s0010952523700545","DOIUrl":"https://doi.org/10.1134/s0010952523700545","url":null,"abstract":"<span> <h3>Abstract</h3> <p>The article demonstrates the advantages of a detailed analysis of remote sensing data for karstological purposes using the Google Earth Engine cloud platform and geographic information systems. The karst area within the Kishert gypsum and carbonate gypsum karst development area in Perm krai was chosen as the study area. The article demonstrates the application of space imagery classification with learning. The purpose of imagery classification is automatic zoning of the territory by type of land cover: meadows and croplands, forests, urbanized areas. In meadows and croplands, calculation of vegetation indices has been carried out in order to delineate potentially karst hazardous areas. The idea of using vegetation indices in assessing surface karst is based on the geobotanical properties of sinkholes in the study area. The relatively high values of vegetation indices within sinkholes reflect the fact that the sides, slopes, and bottoms of sinkholes are covered with shrubby, moisture-loving vegetation. This vegetation is interpreted successfully by calculation of vegetation indices under these conditions. Based on the spatial analysis of the distribution of potentially hazardous areas, a predictive model zoning the study area according to the degree of karst hazard was constructed. As a result of the quantitative assessment of the applicability of the methodology, we can conclude that the areas of coincidence of all four vegetation indices very accurately characterize the distribution of karst forms, and so the comprehensive research of the vegetation indices is very informative in assessing the surface karst distribution.</p> </span>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139979905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differences in the Ocean Color Atmospheric Correction Algorithms for Remote Sensing Reflectance Retrievals for Different Atmospheric Conditions","authors":"","doi":"10.1134/s0010952523700697","DOIUrl":"https://doi.org/10.1134/s0010952523700697","url":null,"abstract":"<span> <h3>Abstract</h3> <p>This work is devoted to estimating the spectral course of validation error of satellite and in situ measurements of remote sensing reflectance for various atmospheric conditions. During data validation, a number of systematic errors of standard algorithms were noted, for example, negative values of remote sensing reflectance in the short-wavelength region at 412 and 443 nm in the presence of dust in the atmosphere. It is shown that the modern approach to determining aerosol light scattering in the short-wavelength part of the visible range by extrapolating the signal from the near-IR region is not sufficiently correct from a physical point of view, and similar solutions by the interpolation method have more accurate estimates. The obtained results show that in the presence of an absorbing aerosol, the spectral law of atmospheric correction errors is close to the function λ^–4. This effect is explained by the fact that dust aerosol is determined by remote sensing methods using the Gordon and Wang algorithms using the infrared channel, but arid aerosol has the main effect on the ratio of the aerosol and molecular components (shortwave range). This paper presents trends for further interpolation of satellite data not only under the condition of a clean atmosphere, but also in the presence of an absorbing aerosol. Experimental patterns of validation error for <em>Aqua</em> MODIS have been obtained.</p> </span>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139980027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of Ionospheric TEC during the Annular and Total Solar Eclipses that Occurred over Indonesia by Using OKSM and FFNN","authors":"S. Kiruthiga, S. Mythili, R. Mukesh, Sarat C. Dass","doi":"10.1134/s001095252360004x","DOIUrl":"https://doi.org/10.1134/s001095252360004x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>People across the world have been fascinated by solar eclipses for thousands of years. Solar eclipses are not only fascinating to observe but also provide opportunities for scientific research. During a solar eclipse, the quantity of solar energy reaching the Earth’s surface is reduced as the Moon passes in front of the Sun. This reduction in solar energy can have an effect on the Total Electron Content of the Earth’s ionosphere. In this paper, prediction and analysis of TEC variations in the Ionosphere during the solar eclipses happened on 26.12.2019 between 04:51 to 7:34 hours (UTC) and 09.03.2016 between 12:18 to 1:02 hours (UTC) over the Indonesia region were done by using two models: Ordinary Kriging based Surrogate Model (OKSM) and Feed-Forward Neural Network (FFNN). During the eclipse period, the TEC values were predicted by the OKSM and FFNN models and it is validated using literature. For this study, the GPS data belonging to the BAKO station situated in Indonesia were collected from IONOLAB servers and the input parameters were collected from the OMNIWEB servers. Forty days prior TEC data and input parameters were used to predict the TEC values. The credibility of the predicted results is assessed using statistical factors such as RMSE, CC, MAE, MAPE, sMAPE and R-Square. The statistical results show OKSM has performed well when compared to the FFNN model over the annular and total solar eclipse period. The study suggests that combining multiple modelling methods, such as OKSM and FFNN can improve our understanding of ionospheric variability during solar eclipses and provide more accurate predictions of TEC variations. This has important implications for satellite communications and navigation systems that rely on accurate TEC measurements for positioning and timing.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138531243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}