Fundamental and Applied Hydrophysics最新文献

{"title":"Numerical Simulation of Temporal Variability of Methane Emissions from Mozhaysk Reservoir","authors":"V. Stepanenko, V. Lomov, M. Grechushnikova","doi":"10.59887/fpg/umx3-6tet-vhkr","DOIUrl":"https://doi.org/10.59887/fpg/umx3-6tet-vhkr","url":null,"abstract":"Estimates of methane emission from the Mozhaysk reservoir surface were carried out using the mathematical model LAKE2.3. The average emission value is 361 tC per year, the average flux = 37.7 mgC–CH4 m–2 day–1. Comparison of the obtained estimates with in situ measurements revealed, that the methane emission and specific flux according to the model are in good agreement with the observations data. The ebullition makes the largest contribution to the total emission. During the heating period, an increase of methane emission is observed with a maximum before the autumn mixing stage. In the course of numerical experiments with the model, it was found that the amplitude of methane fluxes into the atmosphere is associated with fluctuations in atmospheric pressure, and the most significant emissions peaks associated with water level drawdowns. Effective method for calibrating the diffusion component of the methane flux into the atmosphere is the potential rate of methane oxidation in the Michaelis-Menten reaction, and for ebullition it is the methane generation parameter in bottom sediments — q10. For the described numerical experiments, the article presents the values of the annual emissions of methane into the atmosphere. ","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"172 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122882437","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}

{"title":"Reconstructing the Parameters of Internal Tidal Bores in the Banda Sea from Satellite Remote Sensing Data","authors":"V. Novotryasov, V. Dubina, L. Mitnik","doi":"10.59887/fpg/bvve-b2up-ru85","DOIUrl":"https://doi.org/10.59887/fpg/bvve-b2up-ru85","url":null,"abstract":"This article presents an algorithm for estimating the vertical displacements of isopycn and horizontal current velocities caused by internal tidal borings from their manifestations in the roughness field on satellite images of the Banda Sea. The calculation algorithm is formulated within the framework of the Korteweg-de Vries equation (KdV), augmented with a term taking into account the cylindrical divergence. The coefficients of the KdV equation — quadratic nonlinearity, dispersion and tidal linear internal wave velocity — were calculated using the mean — climatic density profile in the Banda Sea. The leading soliton velocity and wavelength in the rear zone of the internal tidal borings were determined from satellite images. Using the proposed methodology, estimates of the maximum vertical displacement of the pycnocline/maximum amplitude of the leading soliton and the maximum velocity of surface currents induced by the internal tidal borings were obtained. It follows from the analysis of satellite images that the internal tidal borings in the Banda Sea are transformed under the action not only of nonlinearity and dispersion, but also of cylindrical divergence. It is shown in the framework of the knoidal model of internal tidal borings that in the process of evolution the energy of its leading and subsequent waves is attenuated due to the cylindrical divergence. This attenuation is estimated when the leading soliton travels a distance equal to twice the tidal period.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114892555","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}

{"title":"Trends in Changes in Primary Phytoplankton Production According to Remote Sensing Data in the Deep-Sea Region of the Black Sea for 1998–2015","authors":"I. V. Kovalyova, Z. Finenko, V. Suslin","doi":"10.59887/fpg/dfbm-t6da-5rvb","DOIUrl":"https://doi.org/10.59887/fpg/dfbm-t6da-5rvb","url":null,"abstract":"The analysis of long-term seasonal changes in the concentration of chlorophyll, the maximum rate of phytoplankton photosynthesis and water temperature in the surface layer of the open waters Black Sea from 1998 to 2015 has been carried out. The trends of these indicators were assessed. For the research, we used the data of satellite observations SeaWiFS and MODIS-Aqua, MODIS-Terra. Typical positive temperature trends of 4 % in the deep-water western part of the sea. An annual temperature rise in deep-water areas was noted in the western cyclonic circulation by 0.038 °C. According to average annual data in other areas, no increase was found. The increase was mainly due to the winter season. Negative trends of primary phytoplankton production within 16.4–18.6 % of the initial level according to average annual values throughout the deep-water area. Significance level — p < 0.1. A decrease in primary production was observed in the summer. There were no statistically significant directional changes in chlorophyll concentration based on averaged data over 18 years. In different parts of the deep-sea area, the direction of interannual and seasonal changes in all indicators was similar. The emerging trend towards a decrease in phytoplankton productivity in recent years may lead to a restructuring of the phytoplankton community.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126994035","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}

{"title":"Spatial and Temporal Variability of the Characteristics of the River Plume Frontal Zone in the Kara Sea in the First Two Decades of the XXI Century","authors":"© А. А. Коник, Алексей Владимирович Зимин, О. А. Атаджанова, A. Konik, A. Zimin, O. A. Atadzhanova, Атаджанова О.А Konik","doi":"10.59887/fpg/38mu-zda7-dpep","DOIUrl":"https://doi.org/10.59887/fpg/38mu-zda7-dpep","url":null,"abstract":"The article is devoted to obtaining long-term physical and geographical characteristics of the River Plume frontal zone as a separate hydrological structure that forms at the boundary of the fresh surface layer of the Ob and Yenisei Rivers. The primary data for identifying the frontal zone are satellite measurements of surface temperature (MODIS Aqua, Suomi NPP-VIIRS), surface salinity (NASA SMAP) and sea level (AVISO) for the period from July to October from 2002 to 2020. The position and characteristics of the River Plume frontal zone were determined using cluster analysis, which was applied for the first time to an integrated set of remote satellite sensing data in this region. The results of the study showed that in the warm period of the year, the average long-term surface temperature gradient of the River Plume frontal zone was 0.08 °C/km, the surface salinity gradient was 0.1 PSU/km, and the area was 155,000 km2. During the ice-free period of the second decade of the 21st century, the temperature gradient of the frontal zone weakens by 0.04 °C/km, and the area decreases by 100,000 km2. The correlation analysis showed that the temperature and salinity gradients, as well as the area of the River Plume frontal zone, were determined by the volumes of the river discharge of the Ob and Yenisei and ice parameters in the warm period of the year. The article presents the obtained estimates of the relationship between the characteristics of the frontal zone and the volume of river discharge, ice cover and wind parameters, as well as the value of the atmospheric indices of the Scandinavian oscillation (SCAND). ","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124495077","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}

{"title":"Examples of the Water Dynamics Influence on the Spatial Distribution of Chlorophyll a Fluorescence Intensity in the Surface Layer of the Barents and Norwegian Seas","authors":"E. Aglova, D. Glukhovets","doi":"10.59887/fpg/dvvv-rrk5-5p2b","DOIUrl":"https://doi.org/10.59887/fpg/dvvv-rrk5-5p2b","url":null,"abstract":"The influence of water dynamics on the spatial distribution of chlorophyll a fluorescence intensity in the surface layer of the Barents and Norwegian Seas, obtained during the 80-th cruise of the R/V “Akademik Mstislav Keldysh” using the flow-through measuring complex in August 2020, was demonstrated. The divergence of the current velocity field, calculated according to reanalysis data, was chosen as a parameter describing the dynamics of water masses. The application of the sliding correlations method allowed us to identify areas of the track with positive and negative correlations between the values of divergence and chlorophyll a fluorescence intensity. It is shown that a positive correlation is formed as a result of the vertical movement of the water surface layer, a negative one — may be a consequence of the water masses advection and the daily changes of the values of photosynthetically active radiation. The part of obtained results is confirmed by satellite data on the spatial distribution of chlorophyll a concentration.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134600218","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}

{"title":"The Chlorophyll-a Content Distribution in the Atlantic Ocean in December 2019 — January 2020 according to Ship Measurements at the Different Hydrometeorological Conditions","authors":"E. A. Shtraikhert, S. Zakharkov, P. Salyuk, V. Ponomarev, V. Artemiev, D. Glukhovets, A. Latushkin","doi":"10.59887/fpg/9rxr-badt-2vde","DOIUrl":"https://doi.org/10.59887/fpg/9rxr-badt-2vde","url":null,"abstract":"The horizontal and vertical chlorophyll-a concentrations (Chl) distributions along the ship route of 79th cruise of R/V “Akademik Mstislav Keldysh” in the Atlantic Ocean in December 2019—January 2020 were obtained. Analysis of the observations was conducted for the biogeochemical provinces which were determined by means of the different hydrometeorological conditions for the phytoplankton community functioning.Three methods of Chl measurements were applied: standard extraction method of the seawater samples, the fluorometer underway measurements in the flow-through water system at the depth of 5 m and in-situ profiling fluorometer measurements at stations. Also, measurements of the seawater temperature and salinity in the flow-through water system, the CTD and optical profiling, and ARGO floats were used.The maximum Chl values in the near-surface ocean layer are observed at zones of divergence in the Canary upwelling systems (CNRY) (1.3 mg/m3) and in the Falkland (Malvinas) Current system (4.8 mg/m3), and also in the Drake Strait (1.2 mg/m3). The least Chl values (0.01–0.12 mg/m3) are observed in the tropical, equatorial areas and in the South Atlantic Subtropical Anticyclonic Gyre (SASTG) at the ship route.Vertical Chl profiles with absence of the significant Chl maximum were found. In the CNRY region the Chl values were not changed much within the euphotic zone. While in the region of the Antarctic Circumpolar Current in the Drake Strait and in the offshore stream of the Falkland Current the quasi-homogeneous Chl profiles were observed in the upper layer which is almost 2 times deeper than the euphotic zone.In the profiles with the significant local Chl maximum the most Chl value of 3.5 mg/m3 is observed at the depth about 12 m in the upwelling region on the Patagonian Shelf. In other regions the depth of Chl maximum localization (0.2–0.9 mg/m3) varies widely from 25 to 120 m. In the western part of the SASTG region the absolute Chl maxima were found at the depth of 120 m, that is deeper, then the euphotic zone which is equal to 100 m.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126131089","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}

{"title":"Algorithms for Evaluation of Biooptical Characteristics in the Gulf of Finland Using Empirical Orthogonal Functions","authors":"S. Vazyulya, S. Sheberstov","doi":"10.59887/fpg/vdeu-bvnr-rxb8","DOIUrl":"https://doi.org/10.59887/fpg/vdeu-bvnr-rxb8","url":null,"abstract":"The paper presents the results of testing the possibility of using empirical orthogonal functions to develop algorithms for estimating the concentration of chlorophyll a and suspended matter, the biomass of cyanobacteria in the eastern part of the Gulf of Finland. To develop the algorithms, we used an array of data from field measurements of the subsurface radiance reflectance in 2012–2014, carried out simultaneously with the determination of bio-optical characteristics. It turned out that in the case of the concentration of chlorophyll a and suspended matter, such algorithms can be created not only using the hyperspectral radiance reflectance, but also for the spectral channels of satellite color scanners MODIS and OLCI. An estimation of the cyanobacteria biomass with the empirical orthogonal functions method is not applicable in the case of using satellite channels. A study of the possibility of the most prone to atmospheric correction errors shortwave MODIS channels exclusion was also made. It turned out that the concentration of chlorophyll a is more sensitive to such exclusion than the concentration of suspended matter. Validation on a MODIS data showed that empirical orthogonal functions algorithms give results no worse than regression ones.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"291 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127556963","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}

{"title":"Characteristics of the Image System based on Photon Density Waves in Observing Underwater Objects through a Waved Surface","authors":"Ульяна Александровна Ульянова, Нижний Новгород","doi":"10.59887/fpg/7k5k-zu86-nxhz","DOIUrl":"https://doi.org/10.59887/fpg/7k5k-zu86-nxhz","url":null,"abstract":"The wavy surface effect on the resolution of optical imaging systems employing narrow modulated probing beams is studied. Relations are formulated connecting the complex amplitudes of the photon density waves (propagating through the wavy interface and the water layer) to the main parameters of the problem. These relations consider the finite waves height and the change in the photon trajectory length due to random refraction of rays upon entering the water. The optical transfer function of the wavy surface and the beam scattering function averaged over the ensemble of surface waving realizations are introduced. The dependences of these functions on the surface waves integral parameters, namely, the elevations and slopes dispersions, are examined. The contributions of surface waving and water layer to the generation of optical transfer functions and to the overall signal level from an underwater object when it is imaged using photon density waves are estimated. It is shown that in a certain range of depths, spatial frequencies, and illumination beam modulation frequencies, the systems employing photon density waves can demonstrate advantages over the systems with stationary illumination.  ","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131392984","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}

{"title":"Data Recovery of the Sea of Azov Salinity Fields Using Regression Analysis Between In Situ Data and Regional Satellite Products","authors":"© Т. Я. Шульга, В. В. Суслин, Д. М. Шукало, ©. T. Ya, Shulga, V. Suslin, D. Shukalo","doi":"10.59887/fpg/bkug-hzez-xx59","DOIUrl":"https://doi.org/10.59887/fpg/bkug-hzez-xx59","url":null,"abstract":"This study proposes a method for obtaining information on the salinity of the Sea of Azov, based on the use of contact and remote sensing data. The approach to the salinity fields recovery is based on obtaining generalized regression equations relating in situ archival data with regional biooptical products obtained from standard level-2 MODIS products. This analysis showed the possibility of using various approaches to obtain generalized empirical (regression) equations for the spring and summer seasons, the differences in which are ~10 %. The results of the recovered salinity values were verified using in situ data. It was found that the plots of the average values of the recovered salinity are in the region of 95 % of the confidence bands of the modern long-term average trends for 1986–2018 and 2000–2018. The possibility of using the results of the proposed method in the construction of spatial maps of the Azov Sea salinity, synchronized in time with satellite scenes, is shown.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131293340","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}

{"title":"Spectral Light Absorption Coefficient of Particles and Colored Dissolved Organic Matter in the Sea of Azov","authors":"©. T. Ya, Churilova, T. Efimova, N. Moiseeva, E. Skorokhod, A. Kovalevsky, Скороход Е.Ю Churilova, T.Ya","doi":"10.59887/fpg/ex1p-9vtp-phu8","DOIUrl":"https://doi.org/10.59887/fpg/ex1p-9vtp-phu8","url":null,"abstract":"The research was carried out based on the results of measuring the concentration of chlorophyll-a (TChl-a), spectral coefficient of light absorption by phytoplankton, non-algal particles (NAP) and colored dissolved organic matter (CDOM) in the southern part of the Sea of Azov in different seasons from 2016 to 2020. New data for the Sea of Azov on the variability of the spectral coefficient of light absorption by all optically active components have been obtained. A high (more than an order of magnitude) variability of all studied parameters was shown. The seasonal dynamics of TChl-a shows maxima in winter and summer. A relationship between the phytoplankton absorption and TChl-a has been revealed, which is described by a power function. Significant seasonal differences (two or more times) between the coefficients in the equation for parametrization of light absorption by phytoplankton were revealed. The NAP and CDOM light absorption were parametrized, the ranges of variability of the absorption coefficient and the exponential slope were revealed, and their seasonal dynamics was shown. Annual variability of absorption coefficient of NAP and CDOM was opposite to the annual cycle of TChl-a. The NAP and CDOM absorption coefficients increased after phytoplankton blooms, when TChl-a decreased. The relative contribution of phytoplankton, NAP, and CDOM to the total absorption by particles and dissolved matter at 440 nm varied significantly over the year. The share of phytoplankton was maximum in winter and summer, while in spring and autumn the maximum contribution to absorption was made by CDOM and NAP.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"165 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123768436","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}