Pub Date : 2024-02-20DOI: 10.1134/s0001433823120022
D. Yu. Abramova, L. M. Abramova
Abstract
The spatial distribution of the lithospheric magnetic anomalies field obtained from German CHAMP satellite measurements for several years of its mission is investigated over the territory of the Indo-Asian collision, in particular, the Tarim region and the Western Himalayan syntax (WHS). Maps of the total intensity Ta of the lithospheric magnetic field for these regions are given. The lithospheric magnetic anomalies field as a reflection of the consequences of the Indian lithospheric plate subduction under the Eurasian plate is discussed in the context of modern ideas about the geological and tectonic structure and geophysical processes of the region. The sign inversion of the magnetic anomalies over the northern part of the Indian Plate observed on Ta maps is supposed as a result of the lower crust heating due to mantle processes, the rise of the Curie isotherm and, as a consequence, the loss of the initial magnetization of the lower crust. In order to study the WHS territory and its surroundings in detail, maps of the lithospheric magnetic anomalies field are constructed at the lowest level of CHAMP orbit as possible, which leads to an increase in their resolution by nearing the field sources. The relationship of detected regional anomalies with tectonic processes in this seismically active area and with other available geophysical information is discussed. An interpretation of the obtained information shows that the images of lithospheric magnetic anomalies distinctly correlate with modern view about the location of large-scale geological and tectonic structures.
{"title":"Lithospheric Magnetic Anomalies According to the CHAMP Satellite Mission Data over the Western Himalayan Syntaxis and Surrounding Areas","authors":"D. Yu. Abramova, L. M. Abramova","doi":"10.1134/s0001433823120022","DOIUrl":"https://doi.org/10.1134/s0001433823120022","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The spatial distribution of the lithospheric magnetic anomalies field obtained from German CHAMP satellite measurements for several years of its mission is investigated over the territory of the Indo-Asian collision, in particular, the Tarim region and the Western Himalayan syntax (WHS). Maps of the total intensity <i>T</i><sub><i>a</i></sub> of the lithospheric magnetic field for these regions are given. The lithospheric magnetic anomalies field as a reflection of the consequences of the Indian lithospheric plate subduction under the Eurasian plate is discussed in the context of modern ideas about the geological and tectonic structure and geophysical processes of the region. The sign inversion of the magnetic anomalies over the northern part of the Indian Plate observed on <i>T</i><sub><i>a</i></sub> maps is supposed as a result of the lower crust heating due to mantle processes, the rise of the Curie isotherm and, as a consequence, the loss of the initial magnetization of the lower crust. In order to study the WHS territory and its surroundings in detail, maps of the lithospheric magnetic anomalies field are constructed at the lowest level of CHAMP orbit as possible, which leads to an increase in their resolution by nearing the field sources. The relationship of detected regional anomalies with tectonic processes in this seismically active area and with other available geophysical information is discussed. An interpretation of the obtained information shows that the images of lithospheric magnetic anomalies distinctly correlate with modern view about the location of large-scale geological and tectonic structures.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-20DOI: 10.1134/s0001433823120174
A. B. Polonsky, A. N. Serebrennikov
Abstract
A general increase in the surface temperature of the Black Sea has been confirmed based on an analysis of satellite data from 1982 to 2021 with a spatial resolution of about 0.05° × 0.05°. The annual mean temperature increase is about 0.6°C/10 years. The annual temperature increase due to a linear trend is maximum in May–June. During these months of hydrological spring, the rate of increase in sea surface temperature (SST) is approximately one and a half times greater than in October–November. During most of the year, the general warming of the surface water layer is not accompanied by a significant increase in the intramonthly SST variance. Such an increase is observed only in some months of transition seasons, especially during the period of hydrological spring, when the absolute value of extreme thermal anomalies and their area increase significantly. The maximum amplitudes of interannual SST variations are confined to the northwestern part of the Black Sea. Changes in the fields of the atmospheric pressure and wind have a significant impact on the spatiotemporal structure of SST. Long-term trends in the surface pressure over the Black Sea indicate an intensification of regional cyclonic activity in the atmosphere (especially pronounced since 2009), which leads to the increased generation of negative SST anomalies of significant amplitude. Such anomalies occur mainly in the warm half of the year (especially in May and October) due to the development of upwellings of wind origin of various types. In May and October, negative SST anomalies in the range of ‒(6–5)°С are characterized by the maximum areas. Warm anomalies are also most often recorded in May and (to a lesser extent) in October. They are generated by anomalous heat fluxes on the sea surface, including those in the shallow areas of the shelf, and spread to open areas of the water basin due to horizontal advection, predominantly of wind origin. The described patterns of spatiotemporal SST variability and their causes are illustrated by a comprehensive analysis of wind and SST fields of high spatial resolution during the development of extreme thermal anomalies.
{"title":"Changes in the Nature of Temperature Anomalies of the Black Sea Surface during the Warming Period of the Late 20th–Early 21st Centuries","authors":"A. B. Polonsky, A. N. Serebrennikov","doi":"10.1134/s0001433823120174","DOIUrl":"https://doi.org/10.1134/s0001433823120174","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A general increase in the surface temperature of the Black Sea has been confirmed based on an analysis of satellite data from 1982 to 2021 with a spatial resolution of about 0.05° × 0.05°. The annual mean temperature increase is about 0.6°C/10 years. The annual temperature increase due to a linear trend is maximum in May–June. During these months of hydrological spring, the rate of increase in sea surface temperature (SST) is approximately one and a half times greater than in October–November. During most of the year, the general warming of the surface water layer is not accompanied by a significant increase in the intramonthly SST variance. Such an increase is observed only in some months of transition seasons, especially during the period of hydrological spring, when the absolute value of extreme thermal anomalies and their area increase significantly. The maximum amplitudes of interannual SST variations are confined to the northwestern part of the Black Sea. Changes in the fields of the atmospheric pressure and wind have a significant impact on the spatiotemporal structure of SST. Long-term trends in the surface pressure over the Black Sea indicate an intensification of regional cyclonic activity in the atmosphere (especially pronounced since 2009), which leads to the increased generation of negative SST anomalies of significant amplitude. Such anomalies occur mainly in the warm half of the year (especially in May and October) due to the development of upwellings of wind origin of various types. In May and October, negative SST anomalies in the range of ‒(6–5)°С are characterized by the maximum areas. Warm anomalies are also most often recorded in May and (to a lesser extent) in October. They are generated by anomalous heat fluxes on the sea surface, including those in the shallow areas of the shelf, and spread to open areas of the water basin due to horizontal advection, predominantly of wind origin. The described patterns of spatiotemporal SST variability and their causes are illustrated by a comprehensive analysis of wind and SST fields of high spatial resolution during the development of extreme thermal anomalies.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-20DOI: 10.1134/s0001433823120113
V. T. Ishmukhametova, I. O. Nafigin, S. A. Ustinov, D. S. Lapaev, V. A. Minaev, V. A. Petrov
Abstract
This work is aimed at the practical application of satellite imagery data for the selection of promising areas during geological exploration work in conditions of medium-low mountainous terrain and a sharply continental climate. The processing results and analysis of WorldView-2 data within the Talmanskaya area are presented in order to identify zones of hydrothermal-metasomatic changes in rocks that are promising for identifying of gold-polymetallic mineralization. The choice of the study area is due to sufficient geological knowledge and the absence of man-made formations that affect the result of processing satellite imagery materials. To increase the spectral information content of the WorldView-2 data, the spectral channel ratio method was used, as a result of which a pseudocolor RGB composite was created that displays the spectral characteristics of objects on the Earth’s day surface, in particular, minerals of the oxide/hydroxide group containing transition iron ions (Fe3+ and Fe3+/Fe2+). A comparison of satellite data processing results along with geological information made it possible to identify spectral anomalies as indicators of the presence of near-ore changes, which are an important search criterion for hydrothermal deposits.
{"title":"Identification of Zones of Hydrothermally Altered Rocks Using WorldView-2 Data at the Talman Site (Talmanskaya Area, South-Eastern Transbaikal, Russia)","authors":"V. T. Ishmukhametova, I. O. Nafigin, S. A. Ustinov, D. S. Lapaev, V. A. Minaev, V. A. Petrov","doi":"10.1134/s0001433823120113","DOIUrl":"https://doi.org/10.1134/s0001433823120113","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This work is aimed at the practical application of satellite imagery data for the selection of promising areas during geological exploration work in conditions of medium-low mountainous terrain and a sharply continental climate. The processing results and analysis of WorldView-2 data within the Talmanskaya area are presented in order to identify zones of hydrothermal-metasomatic changes in rocks that are promising for identifying of gold-polymetallic mineralization. The choice of the study area is due to sufficient geological knowledge and the absence of man-made formations that affect the result of processing satellite imagery materials. To increase the spectral information content of the WorldView-2 data, the spectral channel ratio method was used, as a result of which a pseudocolor RGB composite was created that displays the spectral characteristics of objects on the Earth’s day surface, in particular, minerals of the oxide/hydroxide group containing transition iron ions (Fe<sup>3+</sup> and Fe<sup>3+</sup>/Fe<sup>2+</sup>). A comparison of satellite data processing results along with geological information made it possible to identify spectral anomalies as indicators of the presence of near-ore changes, which are an important search criterion for hydrothermal deposits.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139924171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-20DOI: 10.1134/s0001433823120137
D. V. Khlebnikov, A. Yu. Ivanov, M. A. Evdoshenko, S. K. Klimenko
Abstract
Results of upwelling research in the Black Sea, namely in the northeastern part of the sea, near the Tendrovskaya Spit and western coast of Crimea, and off the coast of Turkey, are presented. The results are based on the use of Earth remote sensing data, in particular the data from color scanners (MODIS, VIIRS, OLCI-A, and OLCI-B), infrared radiometers (TIRS and AVHRR), and SAR images from synthetic aperture radars. An integrated approach using almost exclusively remote sensing data makes it possible to fully characterize the observed upwellings in the Black Sea. In the active phase, upwelling, in addition to sea surface temperature (SST), is usually reflected in both the chlorophyll a (Chl a) concentration field and sea surface roughness field. In our cases, the duration of upwellings varied from 6 to 10 days; the SST differences in the upwelling zone reached 3–8°C; and Chl a concentrations were 5–6 times higher than the background values, being 0.5–0.7 mg/m3. The maximum SST anomalies up to 8°C were observed off the Turkish coast. The analysis revealed a clear relationship between areas of reduced SST in the upwelling zone, sea surface roughness, and Chl a concentration. It is shown that, in the case of using a complete set of remote sensing data, observing, monitoring, and studying upwelling does not present any fundamental difficulties.
{"title":"Manifestation of Upwellings in the Black Sea in Multisensor Remote Sensing Data","authors":"D. V. Khlebnikov, A. Yu. Ivanov, M. A. Evdoshenko, S. K. Klimenko","doi":"10.1134/s0001433823120137","DOIUrl":"https://doi.org/10.1134/s0001433823120137","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Results of upwelling research in the Black Sea, namely in the northeastern part of the sea, near the Tendrovskaya Spit and western coast of Crimea, and off the coast of Turkey, are presented. The results are based on the use of Earth remote sensing data, in particular the data from color scanners (MODIS, VIIRS, OLCI-A, and OLCI-B), infrared radiometers (TIRS and AVHRR), and SAR images from synthetic aperture radars. An integrated approach using almost exclusively remote sensing data makes it possible to fully characterize the observed upwellings in the Black Sea. In the active phase, upwelling, in addition to sea surface temperature (SST), is usually reflected in both the chlorophyll <i>a</i> (Chl <i>a</i>) concentration field and sea surface roughness field. In our cases, the duration of upwellings varied from 6 to 10 days; the SST differences in the upwelling zone reached 3–8°C; and Chl <i>a</i> concentrations were 5–6 times higher than the background values, being 0.5–0.7 mg/m<sup>3</sup>. The maximum SST anomalies up to 8°C were observed off the Turkish coast. The analysis revealed a clear relationship between areas of reduced SST in the upwelling zone, sea surface roughness, and Chl <i>a</i> concentration. It is shown that, in the case of using a complete set of remote sensing data, observing, monitoring, and studying upwelling does not present any fundamental difficulties.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-31DOI: 10.1134/s0001433823090086
P. G. Ilyushina, A. N. Shikhov, O. M. Makarieva
Abstract
Gold mining at ore and alluvial deposits substantially negatively impacts the natural environment, in particular, by land degradation and the contamination of watercourses with suspended solids. In this study, we consider a methodology for identifying and mapping the negative impact of gold mining enterprises on the natural environment based on a long-term series of free-available Landsat and Sentinel-2 satellite images. This study is carried out using the example of Tenkinsky, Susumansky, and Yagodninsky districts in Magadan oblast, where the largest gold deposits are located. Identifying features of active mining areas, as well as abandoned ones (on which vegetation began to recover), have been found in satellite images. Based on the expert interpretation of the images and NDVI analysis, it is found that about 2% of the study area has been affected by gold mining. The processes of vegetation recovery are identified only on 10% of the degraded lands. In the Tenkinsky district, the area of disturbed lands for the period 2001–2021 increased more than seven times, which is associated with a substantial increase in gold mining. Using the C2RCC processor (module of the SNAP software package), the content of suspended solids in the water of the most impacted rivers, the Berelekh, Ayan-Yuryakh, and Kolyma, has been estimated in comparison with natural values (typical for noncontaminated water). We have found that the main source of suspended matter in the rivers is the alluvial gold deposits located in the floodplain of the Berelekh River. At the same time, the seasonal variability of water contamination is determined by the hydrological situation. In particular, water turbidity decreases during low water periods and increases during high-flow periods.
{"title":"Satellite-Based Mapping of the Negative Impact of Gold Mining Enterprises on the Natural Environment of the Cryolithozone (Using the Example of Magadan Oblast)","authors":"P. G. Ilyushina, A. N. Shikhov, O. M. Makarieva","doi":"10.1134/s0001433823090086","DOIUrl":"https://doi.org/10.1134/s0001433823090086","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Gold mining at ore and alluvial deposits substantially negatively impacts the natural environment, in particular, by land degradation and the contamination of watercourses with suspended solids. In this study, we consider a methodology for identifying and mapping the negative impact of gold mining enterprises on the natural environment based on a long-term series of free-available Landsat and Sentinel-2 satellite images. This study is carried out using the example of Tenkinsky, Susumansky, and Yagodninsky districts in Magadan oblast, where the largest gold deposits are located. Identifying features of active mining areas, as well as abandoned ones (on which vegetation began to recover), have been found in satellite images. Based on the expert interpretation of the images and NDVI analysis, it is found that about 2% of the study area has been affected by gold mining. The processes of vegetation recovery are identified only on 10% of the degraded lands. In the Tenkinsky district, the area of disturbed lands for the period 2001–2021 increased more than seven times, which is associated with a substantial increase in gold mining. Using the C2RCC processor (module of the SNAP software package), the content of suspended solids in the water of the most impacted rivers, the Berelekh, Ayan-Yuryakh, and Kolyma, has been estimated in comparison with natural values (typical for noncontaminated water). We have found that the main source of suspended matter in the rivers is the alluvial gold deposits located in the floodplain of the Berelekh River. At the same time, the seasonal variability of water contamination is determined by the hydrological situation. In particular, water turbidity decreases during low water periods and increases during high-flow periods.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139667398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-31DOI: 10.1134/s0001433823090219
L. A. Vedeshin
Abstract
Studies of large-scale space processes and phenomena require the scientific efforts of many countries and the use of expensive technical resources, the development and manufacture of which requires intergovernmental cooperation. These are just some of the things that lead to the need for cooperation in the exploration and use of outer space. From the very beginning of the space age, the Soviet Union offered the international community all kinds of cooperation, and, after its collapse in 1991, Russia, as its legal successor, assumed obligations to implement previously planned international projects under the Intercosmos program and continued cooperation with national space organizations in the United States, Europe, India, China, Japan, etc., on the basis of bilateral intergovernmental agreements.
AbstractStudies of large-scale space processes and phenomena requires the scientific efforts of many countries and the use of expensive technical resources, the development and manufacture of which requires intergovernmental cooperation.这些只是导致探索和利用外层空间需要合作的部分原因。从太空时代一开始，苏联就向国际社会提供了各种合作，1991 年苏联解体后，俄 罗斯作为其合法继承国，承担了根据国际宇宙航行联合会方案实施先前计划的国际项 目的义务，并根据双边政府间协定，继续与美国、欧洲、印度、中国、日本等国家的空 间组织开展合作。
{"title":"International Cooperation in the Research and Use of Outer Space for Peaceful Purposes (on the 55th Anniversary of the Intercosmos Program)","authors":"L. A. Vedeshin","doi":"10.1134/s0001433823090219","DOIUrl":"https://doi.org/10.1134/s0001433823090219","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Studies of large-scale space processes and phenomena require the scientific efforts of many countries and the use of expensive technical resources, the development and manufacture of which requires intergovernmental cooperation. These are just some of the things that lead to the need for cooperation in the exploration and use of outer space. From the very beginning of the space age, the Soviet Union offered the international community all kinds of cooperation, and, after its collapse in 1991, Russia, as its legal successor, assumed obligations to implement previously planned international projects under the Intercosmos program and continued cooperation with national space organizations in the United States, Europe, India, China, Japan, etc., on the basis of bilateral intergovernmental agreements.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140884934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-31DOI: 10.1134/s0001433823090116
A. V. Khoroshev, O. G. Kalmykova, G. Kh. Dusaeva
Abstract
Labor consumption of phytomass measurements on sample plots hinders the extrapolation of point data to areas comparable to commercial lands or landscape units. Vegetation indices calculated from satellite images are usually considered indicators of green phytomass; they are used for its areal estimates. The task of this study is to establish the informativity of the normalized differential vegetation index (NDVI) depending on the fractional structure of living and dead aboveground phytomass, seasonal dynamics of the biological cycle, hydrothermal conditions, and landscape position. The results of monthly measurements of aboveground phytomass fractions on 13 sites in phytocenoses of forest feather grass and feather grass formations in the Burtinskaya steppe (Orenburg Nature Reserve) from May to September 2015–2020 were used. The NDVI values were calculated for each period from Landsat satellite images at all sites. Hypotheses about geobotanical, hydrothermal, phonological, and landscape factors of NDVI informativity were tested by calculating the Spearman correlation coefficients using the dispersion and multiregression analysis. The discrepancy between the seasonal peaks of the NDVI and green phytomass is not consistent with the common concept of a direct indicator value of the NDVI. The total live biomass correlates more clearly with the index in June and July; the correlation is lower in the end of the season. The NDVI index turned out to be sensitive not so much to the reserves of green phytomass, but more to the mass and proportion of forbs and the ratio of live and dead phytomass. In late spring and early summer, the NDVI is most closely associated with forbs and, in July, with cereals. The hypothesis about the possibility of screening green mass with standing dead biomass was confirmed, which leads to a decrease in the NDVI despite the preservation or growth of green phytomass. The NDVI may underestimate the real green phytomass if there is a sharp increase in the mass of standing dead biomass, usually in the second half of summer and early autumn. The NDVI more adequately reflects the state of the aboveground phytomass of steppe communities that have not been exposed to fires for a long time when compared with burned communities and fallows.
{"title":"Evaluation of the Normalized Differential Vegetation Index as a Source of Information on Aboveground Phytomass in Steppes","authors":"A. V. Khoroshev, O. G. Kalmykova, G. Kh. Dusaeva","doi":"10.1134/s0001433823090116","DOIUrl":"https://doi.org/10.1134/s0001433823090116","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Labor consumption of phytomass measurements on sample plots hinders the extrapolation of point data to areas comparable to commercial lands or landscape units. Vegetation indices calculated from satellite images are usually considered indicators of green phytomass; they are used for its areal estimates. The task of this study is to establish the informativity of the normalized differential vegetation index (NDVI) depending on the fractional structure of living and dead aboveground phytomass, seasonal dynamics of the biological cycle, hydrothermal conditions, and landscape position. The results of monthly measurements of aboveground phytomass fractions on 13 sites in phytocenoses of forest feather grass and feather grass formations in the Burtinskaya steppe (Orenburg Nature Reserve) from May to September 2015–2020 were used. The NDVI values were calculated for each period from Landsat satellite images at all sites. Hypotheses about geobotanical, hydrothermal, phonological, and landscape factors of NDVI informativity were tested by calculating the Spearman correlation coefficients using the dispersion and multiregression analysis. The discrepancy between the seasonal peaks of the NDVI and green phytomass is not consistent with the common concept of a direct indicator value of the NDVI. The total live biomass correlates more clearly with the index in June and July; the correlation is lower in the end of the season. The NDVI index turned out to be sensitive not so much to the reserves of green phytomass, but more to the mass and proportion of forbs and the ratio of live and dead phytomass. In late spring and early summer, the NDVI is most closely associated with forbs and, in July, with cereals. The hypothesis about the possibility of screening green mass with standing dead biomass was confirmed, which leads to a decrease in the NDVI despite the preservation or growth of green phytomass. The NDVI may underestimate the real green phytomass if there is a sharp increase in the mass of standing dead biomass, usually in the second half of summer and early autumn. The NDVI more adequately reflects the state of the aboveground phytomass of steppe communities that have not been exposed to fires for a long time when compared with burned communities and fallows.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139667267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-31DOI: 10.1134/s0001433823090128
A. E. Korinenko, V. V. Malinovsky, A. A. Kubryakov
Abstract
The results of using an unmanned aerial vehicle (UAV) to study the processes of gravitational wave breaking are presented. The experiments are carried out in the coastal zone of the western Crimea (the area of Sevastopol) in the range of wind speeds from 5.5 to 9.5 m/s. The determination of the geometric dimensions of breaking and their speeds is carried out according to video recordings of the sea surface obtained from the UAV. It is shown that the spatial resolution of the transformed image plays a key role in separating the active phase of breaking and residual foam. Errors occur in determining the kinematic properties of the breaking with a rough spatial resolution. The proportion of the sea surface covered with foam of breaking waves, the ratio of the maximum length of the spume to the length of the breaking wave, and the distribution of the total breaking length in the intervals of movement speeds per surface unit (obtained from UAVs with a spatial resolution better than 0.5m) are in agreement with results of other authors. Data analysis shows that the use of UAVs makes it possible to study the statistical characteristics and kinematics of wind wave breaking. At the same time, it is necessary to take into account the effect of spatial resolution in the video frame, which can lead to the distortion or omission of measurement data at values comparable to or exceeding the breaking scale.
{"title":"Registering the Peculiarities of Wind Wave Breaking from Unmanned Aerial Vehicles","authors":"A. E. Korinenko, V. V. Malinovsky, A. A. Kubryakov","doi":"10.1134/s0001433823090128","DOIUrl":"https://doi.org/10.1134/s0001433823090128","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of using an unmanned aerial vehicle (UAV) to study the processes of gravitational wave breaking are presented. The experiments are carried out in the coastal zone of the western Crimea (the area of Sevastopol) in the range of wind speeds from 5.5 to 9.5 m/s. The determination of the geometric dimensions of breaking and their speeds is carried out according to video recordings of the sea surface obtained from the UAV. It is shown that the spatial resolution of the transformed image plays a key role in separating the active phase of breaking and residual foam. Errors occur in determining the kinematic properties of the breaking with a rough spatial resolution. The proportion of the sea surface covered with foam of breaking waves, the ratio of the maximum length of the spume to the length of the breaking wave, and the distribution of the total breaking length in the intervals of movement speeds per surface unit (obtained from UAVs with a spatial resolution better than 0.5m) are in agreement with results of other authors. Data analysis shows that the use of UAVs makes it possible to study the statistical characteristics and kinematics of wind wave breaking. At the same time, it is necessary to take into account the effect of spatial resolution in the video frame, which can lead to the distortion or omission of measurement data at values comparable to or exceeding the breaking scale.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139669975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-31DOI: 10.1134/s0001433823090062
A. A. Filei, Yu. A. Shamilova
Abstract
This paper presents a method for cloud water path retrieval from daytime MSU-GS measurements onboard the Russian hydrometeorological satellite Arktika-M 1. The technique is based on the physical principles of the interaction of electromagnetic radiation with cloud particles at wavelengths of 0.55 and 4.0 μm. Cloud water path estimates obtained from the MSU-GS radiometer are compared with similar estimates from the AMSU/MHS and AHI radiometer data. Based on the results of the comparison, the required estimates of the cloud water path of drop clouds are within the permissible limits of the measurement error, not exceeding 50 g/m2. At the same time, due to its design features, the MSU-GS radiometer does not allow retrieving the cloud water path of ice clouds with the required accuracy. On average, the cloud water path estimate of ice clouds according to the MSU-GS data is underestimated by 110 g/m2, and the root-mean-square error is 158 g/m2, when compared to the AHI radiometer data. The estimates of the cloud water path are introduced into the geographic information system Arktika-M, which provides access to the Arktika-M 1 data and the results of their thematic processing in a near real time mode.
{"title":"Retrieval of Cloud Liquid Water Path from MSU-GS Data Onboard Arktika-M 1","authors":"A. A. Filei, Yu. A. Shamilova","doi":"10.1134/s0001433823090062","DOIUrl":"https://doi.org/10.1134/s0001433823090062","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper presents a method for cloud water path retrieval from daytime MSU-GS measurements onboard the Russian hydrometeorological satellite Arktika-M 1. The technique is based on the physical principles of the interaction of electromagnetic radiation with cloud particles at wavelengths of 0.55 and 4.0 μm. Cloud water path estimates obtained from the MSU-GS radiometer are compared with similar estimates from the AMSU/MHS and AHI radiometer data. Based on the results of the comparison, the required estimates of the cloud water path of drop clouds are within the permissible limits of the measurement error, not exceeding 50 g/m<sup>2</sup>. At the same time, due to its design features, the MSU-GS radiometer does not allow retrieving the cloud water path of ice clouds with the required accuracy. On average, the cloud water path estimate of ice clouds according to the MSU-GS data is underestimated by 110 g/m<sup>2</sup>, and the root-mean-square error is 158 g/m<sup>2</sup>, when compared to the AHI radiometer data. The estimates of the cloud water path are introduced into the geographic information system Arktika-M, which provides access to the Arktika-M 1 data and the results of their thematic processing in a near real time mode.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140889786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-31DOI: 10.1134/s0001433823090153
T. N. Prudnikova
Abstract
Studies of the paleogeographical properties of the Ubsunur Basin located on the territory of northwestern Mongolia and southern Tuva are based on the discovery of buried ice veins under Aeolian sediments in the region of Lake Khar-Nur in the eastern mountainous frame of the Great Lakes Basin of Western Mongolia. Satellite images have shown outlines of fields along the periphery of the sand deposits, the natural irrigation of which, in our opinion, was due to the melting of the abovementioned ice. Deposits similar to glacial ones have been found in the river valleys of the northern mountainous framing of the Ubsunur Basin, in its foothill part, suggesting the presence of Pleistocene glaciers extending into its flat plains. It is also assumed on this basis that, similarly to Lake Khar-Nur, the peculiar sandy massifs located in the basin could preserve relic zones of permafrost, the thawing of which contributed to the moistening of local landscapes. Such humidification zones have been seen on satellite images. There are no glacial deposits in this territory in geological legends. At this stage of research, we confirm the presence in the past of thin glaciers in the study site, caused by mountain-forming processes, and the eruption of Quaternary volcanoes on the territory of Tuva and Mongolia. Tectonic processes contributed to the damming of the Tes Khem River, the main waterway flowing along the northern mountain rim of the basin, the formation of dammed lakes, and their subsequent descent. Extended original sandy massifs located in the basin within the Agardag mountain range, previously considered fluvioglacial deposits, are a result of the descent of dammed lakes.
{"title":"Peculiarities of Paleogeography of the Ubsunur Basin in 2022","authors":"T. N. Prudnikova","doi":"10.1134/s0001433823090153","DOIUrl":"https://doi.org/10.1134/s0001433823090153","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Studies of the paleogeographical properties of the Ubsunur Basin located on the territory of northwestern Mongolia and southern Tuva are based on the discovery of buried ice veins under Aeolian sediments in the region of Lake Khar-Nur in the eastern mountainous frame of the Great Lakes Basin of Western Mongolia. Satellite images have shown outlines of fields along the periphery of the sand deposits, the natural irrigation of which, in our opinion, was due to the melting of the abovementioned ice. Deposits similar to glacial ones have been found in the river valleys of the northern mountainous framing of the Ubsunur Basin, in its foothill part, suggesting the presence of Pleistocene glaciers extending into its flat plains. It is also assumed on this basis that, similarly to Lake Khar-Nur, the peculiar sandy massifs located in the basin could preserve relic zones of permafrost, the thawing of which contributed to the moistening of local landscapes. Such humidification zones have been seen on satellite images. There are no glacial deposits in this territory in geological legends. At this stage of research, we confirm the presence in the past of thin glaciers in the study site, caused by mountain-forming processes, and the eruption of Quaternary volcanoes on the territory of Tuva and Mongolia. Tectonic processes contributed to the damming of the Tes Khem River, the main waterway flowing along the northern mountain rim of the basin, the formation of dammed lakes, and their subsequent descent. Extended original sandy massifs located in the basin within the Agardag mountain range, previously considered fluvioglacial deposits, are a result of the descent of dammed lakes.</p>","PeriodicalId":54911,"journal":{"name":"Izvestiya Atmospheric and Oceanic Physics","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139667166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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