Pub Date : 2019-06-11DOI: 10.22449/0233-7584-2019-2-185-196
К.И. Гуров, В Ф Удовик, В. В. Фомин
Introduction . A series of numerical experiments was carried out to study the mechanism of storm deformations of the coastal zone relief and the redistribution of different sediment fractions after the parameters of the wind waves directed almost normally to the coastline, are changed. Data and methods . The lithodynamic processes taking place at the Western Crimea coastal zone in the region of the Lake Bogaily bay-bar were investigated using the XBeach mathematical model. The in-situ data on the bottom relief and the sediments granulometric composition obtained during monitoring observations in the Western Crimea coastal zone performed by the Marine Hydrophysical Institute of RAS was used as the model input parameters. The granulometric composition was preset as a mixture of three components distributed along the profile of the underwater coastal slope; at that the ratios of volume concentrations were different. Results . It is shown that influence of the storm waves results in intensive beach erosion, strong alteration of the profile of the underwater coastal slope upper part and formation of an accumulative body. Main changes of the initial profile and redistribution of the sediment fractions are observed during the first 3–6 hours and depend on the wave period. The rate of the water edge retreat and the values of the coastal zone relief deformation were quantitatively assessed for various time periods of the wave action. Position of the marine boundary of the site within which significant motion of sediments and their accumulation during a storm took place was calculated. Discussion and conclusion . Possibility of the bay-bar crest erosion is analyzed for the wind wave’ different periods. It is shown that the volume concentrations of different components of the mixture change mainly after the fine fractions are rapidly removed to the seaward part of the bottom profile and the coarser fractions are redistributed in the upper part of the underwater coastal slope. The obtained results provide a possibility of indirect determining the conditions for blocking the alongshore sediments transport in case of building a hydraulic structure.
{"title":"МОДЕЛИРОВАНИЕ ШТОРМОВЫХ ИЗМЕНЕНИЙ РЕЛЬЕФА БЕРЕГОВОЙ ЗОНЫ И ГРАНУЛОМЕТРИЧЕСКОГО СОСТАВА НАНОСОВ В РАЙОНЕ ПЕРЕСЫПИ ОЗ. БОГАЙЛЫ (ЗАПАДНЫЙ КРЫМ)","authors":"К.И. Гуров, В Ф Удовик, В. В. Фомин","doi":"10.22449/0233-7584-2019-2-185-196","DOIUrl":"https://doi.org/10.22449/0233-7584-2019-2-185-196","url":null,"abstract":"Introduction . A series of numerical experiments was carried out to study the mechanism of storm deformations of the coastal zone relief and the redistribution of different sediment fractions after the parameters of the wind waves directed almost normally to the coastline, are changed. Data and methods . The lithodynamic processes taking place at the Western Crimea coastal zone in the region of the Lake Bogaily bay-bar were investigated using the XBeach mathematical model. The in-situ data on the bottom relief and the sediments granulometric composition obtained during monitoring observations in the Western Crimea coastal zone performed by the Marine Hydrophysical Institute of RAS was used as the model input parameters. The granulometric composition was preset as a mixture of three components distributed along the profile of the underwater coastal slope; at that the ratios of volume concentrations were different. Results . It is shown that influence of the storm waves results in intensive beach erosion, strong alteration of the profile of the underwater coastal slope upper part and formation of an accumulative body. Main changes of the initial profile and redistribution of the sediment fractions are observed during the first 3–6 hours and depend on the wave period. The rate of the water edge retreat and the values of the coastal zone relief deformation were quantitatively assessed for various time periods of the wave action. Position of the marine boundary of the site within which significant motion of sediments and their accumulation during a storm took place was calculated. Discussion and conclusion . Possibility of the bay-bar crest erosion is analyzed for the wind wave’ different periods. It is shown that the volume concentrations of different components of the mixture change mainly after the fine fractions are rapidly removed to the seaward part of the bottom profile and the coarser fractions are redistributed in the upper part of the underwater coastal slope. The obtained results provide a possibility of indirect determining the conditions for blocking the alongshore sediments transport in case of building a hydraulic structure.","PeriodicalId":43550,"journal":{"name":"Physical Oceanography","volume":"35 1","pages":"185-196"},"PeriodicalIF":0.8,"publicationDate":"2019-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46111854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-01DOI: 10.22449/0233-7584-2019-3-233-247
A. Mizyuk, G. Korotaev
Purpose. During more than 20 years, very detailed notions of the sea level variability in the World Ocean and its particular parts have been obtained based on satellite altimetry observations. Their advantage consists in possibility of a fairly rapid assessment of the surface currents’ velocities at meso scales. The alternative method for studying surface dynamics is motion estimation using a sequence of visible/infrared (IR) satellite images of the sea surface. The purpose of the present study is to compare the results obtaineds from application of two described methods used to analyze general circulation of the Black Sea surface layer. Methods and Results. The structure of the current fields in the northwestern Black Sea in winter, 1999 is investigated using the results of analysis of the IR image sequence from the NOAA/AVHRR sensors, as well as the gridded sea level anomaly (SLA) data (processing level L4) and the along-track measurements (level processing L3) from the Copernicus Marine Environment Monitoring Service. The surface currents’ velocities are estimated based on the sea level field, which is calculated using two versions of mean dynamic topography. To compare the gridded altimetry and the results of the image sequence processing, a simple procedure is proposed for reconstructing the sea level using the current velocities’ components. The results of reconstructing the surface circulation features by two methods were compared and demonstrated, in particular, the anticyclonic eddy locations in the northwestern part of the Black Sea. It is noted that the locations of the eddy center in the sea level fields reconstructed from the altimetry data and by processing of the IR image sequence are different. Evolution of the eddy is investigated using the SLA data. It is shown that its motion is rather intermittent in time that can be a result of applying the procedure of optimal interpolation. Conclusions. It is noted that the gridded satellite altimetry product from the CMEMS, being applied to the Black Sea basin, should be used with due regard for the provided information on the mapping errors.
{"title":"Dynamics of the Black Sea Upper Layer Based on Satellite Data: Gridded Altimetry versus High Resolution IR Images","authors":"A. Mizyuk, G. Korotaev","doi":"10.22449/0233-7584-2019-3-233-247","DOIUrl":"https://doi.org/10.22449/0233-7584-2019-3-233-247","url":null,"abstract":"Purpose. During more than 20 years, very detailed notions of the sea level variability in the World Ocean and its particular parts have been obtained based on satellite altimetry observations. Their advantage consists in possibility of a fairly rapid assessment of the surface currents’ velocities at meso scales. The alternative method for studying surface dynamics is motion estimation using a sequence of visible/infrared (IR) satellite images of the sea surface. The purpose of the present study is to compare the results obtaineds from application of two described methods used to analyze general circulation of the Black Sea surface layer. Methods and Results. The structure of the current fields in the northwestern Black Sea in winter, 1999 is investigated using the results of analysis of the IR image sequence from the NOAA/AVHRR sensors, as well as the gridded sea level anomaly (SLA) data (processing level L4) and the along-track measurements (level processing L3) from the Copernicus Marine Environment Monitoring Service. The surface currents’ velocities are estimated based on the sea level field, which is calculated using two versions of mean dynamic topography. To compare the gridded altimetry and the results of the image sequence processing, a simple procedure is proposed for reconstructing the sea level using the current velocities’ components. The results of reconstructing the surface circulation features by two methods were compared and demonstrated, in particular, the anticyclonic eddy locations in the northwestern part of the Black Sea. It is noted that the locations of the eddy center in the sea level fields reconstructed from the altimetry data and by processing of the IR image sequence are different. Evolution of the eddy is investigated using the SLA data. It is shown that its motion is rather intermittent in time that can be a result of applying the procedure of optimal interpolation. Conclusions. It is noted that the gridded satellite altimetry product from the CMEMS, being applied to the Black Sea basin, should be used with due regard for the provided information on the mapping errors.","PeriodicalId":43550,"journal":{"name":"Physical Oceanography","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48281201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-01DOI: 10.22449/0233-7584-2019-3-273-286
D. Zavyalov
Цель. Целью данной работы было сопоставление результатов численных экспериментов по воспроизведению сезонной термической эволюции толщины морского льда с данными натурных наблюдений ледового режима в северо-восточной части Таганрогского залива. Методы и результаты. Исследование характеристик ледового режима в северо-восточной части Таганрогского залива проведено с помощью построенной термодинамической модели морского льда. В качестве внешнего атмосферного форсинга при проведении численных экспериментов использовались данные реанализа Европейского центра среднесрочных прогнозов ERA-Interim, региональной прогностической модели SKIRON и массива восьмисрочных наблюдений за основными метеорологическими параметрами Всероссийского научно-исследовательского института гидрометеорологической информации − Мирового центра данных (ВНИИГМИ-МЦД) на метеостанции Таганрог. Результаты моделирования сравнивались с данными натурных наблюдений для зимних сезонов с 2007/2008 по 2010/2011 гг. Показано, что характеристики снежно-ледяного покрова, полученные при использовании в качестве внешнего форсинга различных метеорологических данных, могут существенно различаться между собой. Выводы. Наибольшее сходство воспроизведенного и построенного по данным наблюдений сезонного хода толщины льда получено при использовании массива ВНИИГМИ-МЦД. В этом случае модель морского льда удовлетворительно воспроизвела как толщину, так и основные этапы развития снежно-ледяного покрова в Таганрогском заливе. Модель при использовании данных SKIRON оказалась преимущественно переоценивающей, а при использовании данных ERA-Interim – недооценивающей. Это связано в значительной степени с определением количества осадков, прогностические значения которых в ERA-Interim больше, чем в SKIRON. Однако даже в расчетах без учета атмосферных осадков (или в ледовые сезоны с малым их количеством) модель с данными SKIRON дает бόльшие значения толщины льда, чем с данными ERAInterim. Анализ результатов моделирования показал, что для адекватного воспроизведения характеристик ледового режима в Азовском море необходимо проведение предварительной настройки термодинамической модели в зависимости от выбранного массива данных, используемого в качестве атмосферного форсинга.
{"title":"Reconstruction of the Ice Thickness Seasonal Evolution in the Northeastern Sea of Azov Using Different Arrays of Meteorological Data","authors":"D. Zavyalov","doi":"10.22449/0233-7584-2019-3-273-286","DOIUrl":"https://doi.org/10.22449/0233-7584-2019-3-273-286","url":null,"abstract":"Цель. Целью данной работы было сопоставление результатов численных экспериментов по воспроизведению сезонной термической эволюции толщины морского льда с данными натурных наблюдений ледового режима в северо-восточной части Таганрогского залива. Методы и результаты. Исследование характеристик ледового режима в северо-восточной части Таганрогского залива проведено с помощью построенной термодинамической модели морского льда. В качестве внешнего атмосферного форсинга при проведении численных экспериментов использовались данные реанализа Европейского центра среднесрочных прогнозов ERA-Interim, региональной прогностической модели SKIRON и массива восьмисрочных наблюдений за основными метеорологическими параметрами Всероссийского научно-исследовательского института гидрометеорологической информации − Мирового центра данных (ВНИИГМИ-МЦД) на метеостанции Таганрог. Результаты моделирования сравнивались с данными натурных наблюдений для зимних сезонов с 2007/2008 по 2010/2011 гг. Показано, что характеристики снежно-ледяного покрова, полученные при использовании в качестве внешнего форсинга различных метеорологических данных, могут существенно различаться между собой. Выводы. Наибольшее сходство воспроизведенного и построенного по данным наблюдений сезонного хода толщины льда получено при использовании массива ВНИИГМИ-МЦД. В этом случае модель морского льда удовлетворительно воспроизвела как толщину, так и основные этапы развития снежно-ледяного покрова в Таганрогском заливе. Модель при использовании данных SKIRON оказалась преимущественно переоценивающей, а при использовании данных ERA-Interim – недооценивающей. Это связано в значительной степени с определением количества осадков, прогностические значения которых в ERA-Interim больше, чем в SKIRON. Однако даже в расчетах без учета атмосферных осадков (или в ледовые сезоны с малым их количеством) модель с данными SKIRON дает бόльшие значения толщины льда, чем с данными ERAInterim. Анализ результатов моделирования показал, что для адекватного воспроизведения характеристик ледового режима в Азовском море необходимо проведение предварительной настройки термодинамической модели в зависимости от выбранного массива данных, используемого в качестве атмосферного форсинга.","PeriodicalId":43550,"journal":{"name":"Physical Oceanography","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45794264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-01DOI: 10.22449/1573-160x-2019-3-185-201
A. Pavlushin, N. B. Shapiro, E. N. Mikhailova
Purpose. The present article is aimed to carry out the energy analysis of the numerical experiment results obtained from modeling of the large-scale circulation in the Black Sea within the framework of a two-layer eddy-resolving model under the tangential wind stress forcing, and also to determine directions and magnitudes of the energy transitions accompanying formation of the large-scale flows and mesoscale eddies in the sea. Methods and Results. The analysis is carried out for the period of statistical equilibrium in which the average values of all the characteristics calculated in the model remain constant in time. According to the motion scales, the Reynolds averaging method permits to divide the energy characteristics (mechanical energy and its transitions) into those relating to the large-scale flows and – to the eddies. The large-scale currents are defined as average flows over a certain selected time interval, and the deviations from them are considered to be the vortices. The energy characteristics averaged over time and/or space, are analyzed. For the period of statistical equilibrium, calculated are the energy diagrams showing contribution of the large-scale currents and the vortices to the total mechanical energy, to the magnitudes and directions of energy transitions. The time-averaged fields both of the energy components and the forces involved in the energy balance were constructed for the same period. Conclusions. It is shown that baroclinic instability of a large-scale flow is the main cause of the Rim Current meandering, and the energy is transferred to the bottom layer due to baroclinic instability of the eddies. It has been revealed that a large portion of wind energy falls on the eastern part of the sea, whereas the energy losses take place in the western and northwestern regions of the basin. The basic part of energy dissipation takes place due to the friction forces’ work on the lower boundary of the upper layer in the area where the layer interfaces intersect the bottom.
{"title":"Energy Transitions in the Two-Layer Eddy-Resolving Model of the Black Sea","authors":"A. Pavlushin, N. B. Shapiro, E. N. Mikhailova","doi":"10.22449/1573-160x-2019-3-185-201","DOIUrl":"https://doi.org/10.22449/1573-160x-2019-3-185-201","url":null,"abstract":"Purpose. The present article is aimed to carry out the energy analysis of the numerical experiment results obtained from modeling of the large-scale circulation in the Black Sea within the framework of a two-layer eddy-resolving model under the tangential wind stress forcing, and also to determine directions and magnitudes of the energy transitions accompanying formation of the large-scale flows and mesoscale eddies in the sea. Methods and Results. The analysis is carried out for the period of statistical equilibrium in which the average values of all the characteristics calculated in the model remain constant in time. According to the motion scales, the Reynolds averaging method permits to divide the energy characteristics (mechanical energy and its transitions) into those relating to the large-scale flows and – to the eddies. The large-scale currents are defined as average flows over a certain selected time interval, and the deviations from them are considered to be the vortices. The energy characteristics averaged over time and/or space, are analyzed. For the period of statistical equilibrium, calculated are the energy diagrams showing contribution of the large-scale currents and the vortices to the total mechanical energy, to the magnitudes and directions of energy transitions. The time-averaged fields both of the energy components and the forces involved in the energy balance were constructed for the same period. Conclusions. It is shown that baroclinic instability of a large-scale flow is the main cause of the Rim Current meandering, and the energy is transferred to the bottom layer due to baroclinic instability of the eddies. It has been revealed that a large portion of wind energy falls on the eastern part of the sea, whereas the energy losses take place in the western and northwestern regions of the basin. The basic part of energy dissipation takes place due to the friction forces’ work on the lower boundary of the upper layer in the area where the layer interfaces intersect the bottom.","PeriodicalId":43550,"journal":{"name":"Physical Oceanography","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46258256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-01DOI: 10.22449/0233-7584-2019-3-261-272
T. Grankina, R. Ibrayev, P. A. Mogilnikov
Purpose. The purpose of the paper is to assess quality of meteorological information for the Azov–Black Sea basin derived from the ERA-Interim reanalysis (the European Centre for Medium-Range Weather Forecasts), and to examine possibility of using the obtained data for presetting atmospheric forcing in the numerical hydrodynamic model of the Black and Azov seas. Methods. The analysis is based on comparison of the annual average ERA-Interim fields with the measurement data on the atmospheric circulation parameters represented in hydrometeorological atlases. The most significant discrepancies between the ERA-Interim fields and the data of climatic arrays are noted and, consequently, the discrepancy-related potential errors arising in reproducing water circulation in the indicated seas are considered. Results and Conclusions. The comparative analysis showed that, for a number of the parameters, the reanalysis data were in qualitative agreement with the measurements. The highest discrepancies (up to 70%) were revealed in the precipitation field nearby the Caucasian coast in autumn. Such an error in the boundary conditions can negatively affect both the sea surface salinity distribution in the numerical modeling and, therefore, reproduction of thermohaline circulation in this region of the sea. A significant error in the results of numerical modeling can also be induced by the discrepancies in the wind fields. In the ERA-Interim data, the wind speed module is generally understated by 7% over the whole Black Sea in a spring-summer period, and by 20–25% in the Azov Sea throughout a year. The direction of the resultant wind is the most distorted in summer, whereas in winter, the deviations are significant only in the southeastern part of the Black Sea. The best agreement is observed between the temperature and air humidity fields, and the climatic arrays’ data: the discrepancies between the values of these parameters are minimal.
{"title":"Verification of the ERA-Interim Reanalysis Data in the Azov-Black Sea Basin","authors":"T. Grankina, R. Ibrayev, P. A. Mogilnikov","doi":"10.22449/0233-7584-2019-3-261-272","DOIUrl":"https://doi.org/10.22449/0233-7584-2019-3-261-272","url":null,"abstract":"Purpose. The purpose of the paper is to assess quality of meteorological information for the Azov–Black Sea basin derived from the ERA-Interim reanalysis (the European Centre for Medium-Range Weather Forecasts), and to examine possibility of using the obtained data for presetting atmospheric forcing in the numerical hydrodynamic model of the Black and Azov seas. Methods. The analysis is based on comparison of the annual average ERA-Interim fields with the measurement data on the atmospheric circulation parameters represented in hydrometeorological atlases. The most significant discrepancies between the ERA-Interim fields and the data of climatic arrays are noted and, consequently, the discrepancy-related potential errors arising in reproducing water circulation in the indicated seas are considered. Results and Conclusions. The comparative analysis showed that, for a number of the parameters, the reanalysis data were in qualitative agreement with the measurements. The highest discrepancies (up to 70%) were revealed in the precipitation field nearby the Caucasian coast in autumn. Such an error in the boundary conditions can negatively affect both the sea surface salinity distribution in the numerical modeling and, therefore, reproduction of thermohaline circulation in this region of the sea. A significant error in the results of numerical modeling can also be induced by the discrepancies in the wind fields. In the ERA-Interim data, the wind speed module is generally understated by 7% over the whole Black Sea in a spring-summer period, and by 20–25% in the Azov Sea throughout a year. The direction of the resultant wind is the most distorted in summer, whereas in winter, the deviations are significant only in the southeastern part of the Black Sea. The best agreement is observed between the temperature and air humidity fields, and the climatic arrays’ data: the discrepancies between the values of these parameters are minimal.","PeriodicalId":43550,"journal":{"name":"Physical Oceanography","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41442432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-01DOI: 10.22449/0233-7584-2019-2-147-159
N. Diansky, V. Fomin, A. Grigoriev, A. Chaplygin, A. Zatsepin
Lomonosov Moscow State University, Moscow, Russian Federation Zubov State Oceanographic Institute, Moscow, Russian Federation Marchuk Institute of Numerical Mathematics, Russian Academy of Sciences, Moscow, Russian Federation Moscow Institute of Physics and Technology (national research university), Dolgoprudny, Russian Federation Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russian Federation *e-mail: nikolay.diansky@gmail.com
{"title":"Spatial-temporal variability of inertial currents in the eastern part of the Black Sea in a storm period","authors":"N. Diansky, V. Fomin, A. Grigoriev, A. Chaplygin, A. Zatsepin","doi":"10.22449/0233-7584-2019-2-147-159","DOIUrl":"https://doi.org/10.22449/0233-7584-2019-2-147-159","url":null,"abstract":"Lomonosov Moscow State University, Moscow, Russian Federation Zubov State Oceanographic Institute, Moscow, Russian Federation Marchuk Institute of Numerical Mathematics, Russian Academy of Sciences, Moscow, Russian Federation Moscow Institute of Physics and Technology (national research university), Dolgoprudny, Russian Federation Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russian Federation *e-mail: nikolay.diansky@gmail.com","PeriodicalId":43550,"journal":{"name":"Physical Oceanography","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46434717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-01DOI: 10.22449/0233-7584-2019-2-134-146
V. Efimov, O. Komarovskaya
Introduction . Influence of the Crimean Mountains on the wind regime in the Crimea region for different seasons and wind directions is considered. Data and methods . Data on the monthly average temperature values on the model levels of the ERA Interim reanalysis [10] for 40 years (1979–2018) and also the results of modeling using the regional numerical model of atmospheric circulation WRF-ARW are used. Results . The fields of surface wind speeds in the Crimea region are considered at the northern and southern directions of the background wind which are close to the normal one in relation to the ridge. Annual variation of buoyancy frequency for the flat regions of the Crimea Peninsula and for its Southern Coast separated from them by the Crimean Mountains is given. The periods of the most probable disturbances in the surface wind fields induced by the Crimean Mountains are revealed. Using the regional atmospheric circulation model WRF-ARW, the wind speed fields for a few typical directions of the background undisturbed wind are simulated. Discussion and conclusions. It is shown that in a spring-summer period (April–June) in the atmosphere over the sea, the conditions required to block the air flow from the south to the Crimean Mountains ridge arise. As a result, an alongshore flow is formed, and the mesoscale zone of speed perturbations springs up. At the northern winds, stable stratification in the boundary layer over the Crimea land areas is observed, on the average, throughout the whole year, except for four summer-autumn months (June–September); significant wind speed disturbances can also develop. However, they are of local character, i.e. concentrated directly near the mountain ridge and over the leeward slope where the velocity disturbances of a bora type are formed in a narrow coastal zone. Repeatability statistics of these two cases of the wind speed field perturbation caused by the mountains is assessed and considered. WRF-ARW model. Acknowledgments: t he investigation was carried within the framework of the state tasks on theme studies of the interaction processes in ocean-atmosphere system
{"title":"Disturbances in the wind speed fields due to the Crimean Mountains","authors":"V. Efimov, O. Komarovskaya","doi":"10.22449/0233-7584-2019-2-134-146","DOIUrl":"https://doi.org/10.22449/0233-7584-2019-2-134-146","url":null,"abstract":"Introduction . Influence of the Crimean Mountains on the wind regime in the Crimea region for different seasons and wind directions is considered. Data and methods . Data on the monthly average temperature values on the model levels of the ERA Interim reanalysis [10] for 40 years (1979–2018) and also the results of modeling using the regional numerical model of atmospheric circulation WRF-ARW are used. Results . The fields of surface wind speeds in the Crimea region are considered at the northern and southern directions of the background wind which are close to the normal one in relation to the ridge. Annual variation of buoyancy frequency for the flat regions of the Crimea Peninsula and for its Southern Coast separated from them by the Crimean Mountains is given. The periods of the most probable disturbances in the surface wind fields induced by the Crimean Mountains are revealed. Using the regional atmospheric circulation model WRF-ARW, the wind speed fields for a few typical directions of the background undisturbed wind are simulated. Discussion and conclusions. It is shown that in a spring-summer period (April–June) in the atmosphere over the sea, the conditions required to block the air flow from the south to the Crimean Mountains ridge arise. As a result, an alongshore flow is formed, and the mesoscale zone of speed perturbations springs up. At the northern winds, stable stratification in the boundary layer over the Crimea land areas is observed, on the average, throughout the whole year, except for four summer-autumn months (June–September); significant wind speed disturbances can also develop. However, they are of local character, i.e. concentrated directly near the mountain ridge and over the leeward slope where the velocity disturbances of a bora type are formed in a narrow coastal zone. Repeatability statistics of these two cases of the wind speed field perturbation caused by the mountains is assessed and considered. WRF-ARW model. Acknowledgments: t he investigation was carried within the framework of the state tasks on theme studies of the interaction processes in ocean-atmosphere system","PeriodicalId":43550,"journal":{"name":"Physical Oceanography","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45014730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-01DOI: 10.22449/1573-160X-2019-2-104-122
P. Lishaev, V. Knysh, G. Korotaev
{"title":"Modelling of Water Pollution Propagation in the Sevastopol Bay","authors":"P. Lishaev, V. Knysh, G. Korotaev","doi":"10.22449/1573-160X-2019-2-104-122","DOIUrl":"https://doi.org/10.22449/1573-160X-2019-2-104-122","url":null,"abstract":"","PeriodicalId":43550,"journal":{"name":"Physical Oceanography","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44969543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-01DOI: 10.22449/0233-7584-2019-2-105-113
M. Kaurkin, R. Ibrayev
Introduction. The analysis of the original parallel realization of the ensemble optimal interpolation (EnOI) method for data assimilation in the ocean dynamics model developed in the Institute of Numerical Mathematics and the Institute of Oceanology (INMIO model) with a resolution 0.1° for the North Atlantic region is given in the present paper. Data and methods. Based on the known (“true”) model state of the ocean, the temperature profiles (about 70 per day, up to 1500 m depth) were chosen and used as synthetic observational data. After the initial condition was perturbed, the numerical experiments were carried out to estimate speed and accuracy of approaching the entire model solution to the “true” state of the ocean as the temperature profiles were assimilated. Results. Both qualitative analysis of the results and the graphs of the root-mean-square and mean errors of the model solution are given. To study the method sensitivity to the amount of the observational data, the experiments with carried out. They showed that assimilation even of the isolated data could significantly increase the model forecast quality. Discussion and conclusion. The experiments prove that application of the ensemble optimal interpolation method, even in case very few data, are assimilated in the model, can significantly improve quality both of the model forecast and the entire model solution for those regions where the observational data are very scarce or absent at all. Thus, due to assimilation of the data covering only 3–4 days, the root-mean-square error for the sea surface temperature model field decreases by 1.5oC, and the average deviation becomes equal almost to zero over the entire computational domain.
{"title":"Study of sensitivity of the algorithm for assimilating small amount of data in the ocean dynamics model","authors":"M. Kaurkin, R. Ibrayev","doi":"10.22449/0233-7584-2019-2-105-113","DOIUrl":"https://doi.org/10.22449/0233-7584-2019-2-105-113","url":null,"abstract":"Introduction. The analysis of the original parallel realization of the ensemble optimal interpolation (EnOI) method for data assimilation in the ocean dynamics model developed in the Institute of Numerical Mathematics and the Institute of Oceanology (INMIO model) with a resolution 0.1° for the North Atlantic region is given in the present paper. Data and methods. Based on the known (“true”) model state of the ocean, the temperature profiles (about 70 per day, up to 1500 m depth) were chosen and used as synthetic observational data. After the initial condition was perturbed, the numerical experiments were carried out to estimate speed and accuracy of approaching the entire model solution to the “true” state of the ocean as the temperature profiles were assimilated. Results. Both qualitative analysis of the results and the graphs of the root-mean-square and mean errors of the model solution are given. To study the method sensitivity to the amount of the observational data, the experiments with carried out. They showed that assimilation even of the isolated data could significantly increase the model forecast quality. Discussion and conclusion. The experiments prove that application of the ensemble optimal interpolation method, even in case very few data, are assimilated in the model, can significantly improve quality both of the model forecast and the entire model solution for those regions where the observational data are very scarce or absent at all. Thus, due to assimilation of the data covering only 3–4 days, the root-mean-square error for the sea surface temperature model field decreases by 1.5oC, and the average deviation becomes equal almost to zero over the entire computational domain.","PeriodicalId":43550,"journal":{"name":"Physical Oceanography","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42310651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-01DOI: 10.22449/1573-160x-2019-2-170-180
K. Gurov, V. Udovik, V. Fomin
Introduction . A series of numerical experiments was carried out to study the mechanism of storm deformations of the coastal zone relief and the redistribution of different sediment fractions after the parameters of the wind waves directed almost normally to the coastline, are changed. Data and methods . The lithodynamic processes taking place at the Western Crimea coastal zone in the region of the Lake Bogaily bay-bar were investigated using the XBeach mathematical model. The in-situ data on the bottom relief and the sediments granulometric composition obtained during moni-toring observations in the Western Crimea coastal zone performed by the Marine Hydrophysical Institute of RAS was used as the model input parameters. The granulometric composition was preset as a mixture of three components distributed along the profile of the underwater coastal slope; at that the ratios of volume concentrations were different. Results . It is shown that influence of the storm waves results in intensive beach erosion, strong altera-tion of the profile of the underwater coastal slope upper part and formation of an accumulative body. Main changes of the initial profile and redistribution of the sediment fractions are observed during the first 3–6 hours and depend on the wave period. The rate of the water edge retreat and the values of the coastal zone relief deformation were quantitatively assessed for various time periods of the wave action. Position of the marine boundary of the site within which significant motion of sediments and their accumulation during a storm took place was calculated. Discussion and conclusion . Possibility of the bay-bar crest erosion is analyzed for the wind wave’ different periods. It is shown that the volume concentrations of different components of the mixture change mainly after the fine fractions are rapidly removed to the seaward part of the bottom profile and the coarser fractions are redistributed in the upper part of the underwater coastal slope. The obtained results provide a possibility of indirect determining the conditions for blocking the alongshore sediments transport in case of building a hydraulic structure.
{"title":"Modeling of the coastal zone relief and granulometric composition changes of sediments in the region of the Bogaily Lake bay-bar (the Western Crimea) during storm","authors":"K. Gurov, V. Udovik, V. Fomin","doi":"10.22449/1573-160x-2019-2-170-180","DOIUrl":"https://doi.org/10.22449/1573-160x-2019-2-170-180","url":null,"abstract":"Introduction . A series of numerical experiments was carried out to study the mechanism of storm deformations of the coastal zone relief and the redistribution of different sediment fractions after the parameters of the wind waves directed almost normally to the coastline, are changed. Data and methods . The lithodynamic processes taking place at the Western Crimea coastal zone in the region of the Lake Bogaily bay-bar were investigated using the XBeach mathematical model. The in-situ data on the bottom relief and the sediments granulometric composition obtained during moni-toring observations in the Western Crimea coastal zone performed by the Marine Hydrophysical Institute of RAS was used as the model input parameters. The granulometric composition was preset as a mixture of three components distributed along the profile of the underwater coastal slope; at that the ratios of volume concentrations were different. Results . It is shown that influence of the storm waves results in intensive beach erosion, strong altera-tion of the profile of the underwater coastal slope upper part and formation of an accumulative body. Main changes of the initial profile and redistribution of the sediment fractions are observed during the first 3–6 hours and depend on the wave period. The rate of the water edge retreat and the values of the coastal zone relief deformation were quantitatively assessed for various time periods of the wave action. Position of the marine boundary of the site within which significant motion of sediments and their accumulation during a storm took place was calculated. Discussion and conclusion . Possibility of the bay-bar crest erosion is analyzed for the wind wave’ different periods. It is shown that the volume concentrations of different components of the mixture change mainly after the fine fractions are rapidly removed to the seaward part of the bottom profile and the coarser fractions are redistributed in the upper part of the underwater coastal slope. The obtained results provide a possibility of indirect determining the conditions for blocking the alongshore sediments transport in case of building a hydraulic structure.","PeriodicalId":43550,"journal":{"name":"Physical Oceanography","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49455610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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