Fundamental and Applied Hydrophysics最新文献

{"title":"Some Remarks on the Phase Transformation of Gas Hydrates in Porous Sediments at Negative Celsius Temperatures","authors":"A. Golmshtok","doi":"10.59887/2073-6673.2023.16(4)-8","DOIUrl":"https://doi.org/10.59887/2073-6673.2023.16(4)-8","url":null,"abstract":"The article presents a solution to the problem of the phase transition of methane hydrate — methane-gas + ice in porous hydrate-containing sediments at a negative Celsius temperature in the medium. The numerical solution of the resulting system of differential equations of piezoand thermal conductivity makes it possible to effectively simulate the change in pressure and temperature in both time and space in a medium of any dimension during its heating or decompression. In this case, the medium is not subdivided into parts with varying phase states of methane hydrate. Instead, its sediment substance is considered as a single entity, with its physical properties changing in magnitude when the hydrates undergo phase transformation. As an example, the problem of the thermobaric regime of a heating spherical cavern containing ice, hydrate and free methane has been solved. This cavern is situated within a continuous gas-tight underground ice. The solution shows that although the temperature of the sphere surface increases considerably, the decomposition of hydrate only occurs in an extremely thin shell located directly between the surface and the displaced inward phase boundary.Over time, the stability conditions of hydrates establish anew but at a higher gas pressure and medium temperature. This phenomenon of severely limited decomposition of the hydrate in a closed gas-insulated space, nevertheless leading to an increase in pressure in it, is, apparently, the basic process that provides the “self-preservation” of methane hydrates.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"61 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139534814","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 Results of Oceanographic Studies in the Marginal Ice Zone of the Barents Sea in the Spring of 2023","authors":"T. M. Maksimovskaya, A. V. Zimin, D. V. Moiseev","doi":"10.59887/2073-6673.2023.16(4)-7","DOIUrl":"https://doi.org/10.59887/2073-6673.2023.16(4)-7","url":null,"abstract":"The results of oceanographic research in the marginal ice zone of the Barents Sea near the ice cover boundary, carried out from the R/V Dalnie Zelentsy from April 27 to May 6, 2023, are presented. The position of the frontal zones recorded from contact observations on hydrological meridional transects along 33°30′, 40°, 45°, and 50° E are considered. The transects were made from the fields of finely broken annual ice southward towards the open water area of the Barents Sea. High-gradient zones expressed in the temperature and salinity fields at different distances from the ice field edge were detected on all transects. It was shown that during the research period the frontal zone was located at a distance from 25 to 180 km from the ice field edge, the temperature gradients varied from 0.021 to 0.067 °C/km, the salinity — from 0.002 to 0.012 psu/km, the width of the frontal zone did not exceed 28 km. The maximum values of chlorophyll-a and dissolved oxygen were observed in the area of the frontal zone boundary.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":" 83","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139628315","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":"Arctic Ocean acidification dynamics during 1993–2021 and its projections for the rest of this century","authors":"A. S. Malysheva, I. V. Radchenko, D. Pozdnyakov","doi":"10.59887/2073-6673.2023.16(4)-5","DOIUrl":"https://doi.org/10.59887/2073-6673.2023.16(4)-5","url":null,"abstract":"Dynamics of acidification of the Arctic Ocean through 1993–2021 and predictions of further tendencies of this process until the end of 2100 were assessed making use of both the GLODAPv.2021 and the Global Ocean Biogeochremistry Hindcast (GOBH) reanalysis data on pH. The projections of pH were performed by CMIP6 models for four scenarios of rates of socio-economic and agricultural development and emissions of greenhouse gases: SSP1–2.6, SSP2–4.5, SSP3–7.0 and SSP5–8.5.The tendencies of pH decline over the last 27 years (1993–2019) as determined from the GLODAP in situ and the reanalysis data over 1993–2021 proved to be, respectively –0.9% (from 8.18–8.11) and –0.7% (from 8.10–8.05). Thus, the annual acidification rate as assessed from both data sources proved to be –0.03%.Through the percentile method-based comparison of consistency of historical observation data on pH with GBH model hindcast four best models were identified: MPI-ESM1–2-LR, NorESM2-MM, NorESM2-LM, and CMCC-ESM2. The projection results strongly indicate that the Arctic Ocean acidification will continue till the end of this century. The highest rates of pH decrease (–4.9% and –6.2%) were forecasted, respectively, for scenarios SSP3–7.0 and SSP5–8.5 that implied the global mean temperature increases by 3.6 °C and 4.4 °C, respectively. A comparison of the results obtained with the previously made assessments is indicative that by the end of the current century the rate of acidification (i. e. pH decrease) in the Arctic should be expected to be higher than that averaged over the World Oceans: the difference for each of the SSP scenarios proved to be –0.1.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":" 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139628408","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":"Features of Fluorescence Profiles and Species Composition of Phytoplankton in the Black Sea and the Sea of Azov","authors":"О. B. Kudinov, V. Suslin, R. I. Lee, D. A. Ryabokon","doi":"10.59887/2073-6673.2023.16(4)-6","DOIUrl":"https://doi.org/10.59887/2073-6673.2023.16(4)-6","url":null,"abstract":"The aim of this work was to study the properties of vertical fluorescence intensity (FI) profiles of phytoplankton pigments (chlorophyll-a, phycocyanin, phycoerythrin, and beta-carotene) using data on the phytoplankton species composition obtained during the cruise 114 of the R/V ‘Professor Vodyanitsky’. The analysis of covariance matrices of phytoplankton pigment FI profiles in the upper 50-meter layer of the Black Sea indicates that the pigment composition of phytoplankton changes with depth, which may be associated with changes in its species composition. At the same time, 80 % variability of phytoplankton pigment FI profiles in the upper 20-meter layer is described by the first eigenvector. It agrees well with direct observations of the phytoplankton species composition, indicating the dominance of one phytoplankton division in the 20-meter layer. In addition, there are regional peculiarities: for example, the average FI values of the phytoplankton pigments in the Sea of Azov are significantly higher than those in the Black Sea, which is associated with a higher concentration of phytoplankton in the Sea of Azov.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"52 26","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139534976","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":"Modeling of Barotropic Tide off the Southeastern Coast of the Kamchatka Peninsula in View of the Accuracy of Global Tidal Models in the Northwest Pacific Ocean","authors":"D. Romanenkov, E. Sofina, A. E. Rodikova","doi":"10.59887/2073-6673.2023.16(4)-4","DOIUrl":"https://doi.org/10.59887/2073-6673.2023.16(4)-4","url":null,"abstract":"This study introduces the development and implementation of a regional numerical finite-volume model FESOM–C, specifically designed to accurately compute barotropic tidal dynamics in the Pacific waters adjacent to the southeastern region of the Kamchatka Peninsula. The dynamics of principal harmonics of the semidiurnal M2 and diurnal K1 tidal constituents are replicated, as well as the total tide, which encompasses 12 constituents. The computed results, obtained using a detailed unstructured grid, are interpreted through the Long-wave approach. The FESOM–C regional model revealed the variability of harmonic constants of tide and current characteristics within the shelf and canyon-cut continental slope, due to topographic scattering of tidal waves. The assessment includes the estimation of maximum currents and eddy structures associated with residual tidal circulation on the shelf and continental slope. To investigate the influence of varying open boundary conditions, sensitivity experiments have been conducted using data from two state-of-the-art global tidal models FES2014 and TPXO9. The findings reveal that the regional model’s solution exhibits only minimal dependency on this choice, and it aligns well with the limited available tidal data. Interestingly, the global models themselves demonstrate significant disparities in the tidal currents. Furthermore, we assess the accuracy of global tidal model solutions in a broader region encompassing the Sea of Okhotsk, as well as the Pacific waters along the Kuril Islands and the Kamchatka Peninsula. This assessment utilizes a verified database of tidal harmonic constants derived from the Soviet and British tide tables. While the average errors in tidal heights calculations remain minor and closely approximate officially declared values, certain areas within the region exhibit notable discrepancies in the outputs of the global models. These discrepancies are site-specific and vary depending on the particular model and tidal harmonic under consideration. This underscores the need for caution when applying results from global tidal models at the regional scale. Meanwhile, the importance of advancing regional tidal dynamics modeling remains evident.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"145 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139629129","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":"Effect of Surface Waves on Settling and Drifting of Microplastic Particles: A Laboratory Experiment","authors":"I. A. Isachenko, I. M. Kraev, D. Sergeev","doi":"10.59887/2073-6673.2023.16(4)-3","DOIUrl":"https://doi.org/10.59887/2073-6673.2023.16(4)-3","url":null,"abstract":"Particle trajectories and average settling and drift velocities of microplastic particles under wave action were studied in a linear wind-wave channel. A wave-maker and an airflow above the water surface created various hydrodynamic conditions. Particles of various shapes (isometric, flat, elongated) were used. The paper provides a brief overview of the theoretical approaches (dimensional analysis) used to study the transport of microplastics in the presence of surface waves and currents. Based on this, a characteristic of wave regimes and sets of experimental particles is given. Terminal settling velocities of the particles in a quiet fluid are 1.0–3.8 cm/s. They were obtained experimentally and may be of independent interest. The settling trajectories of 13 types of particles in 4 wave regimes were obtained and analyzed. According to Welch’s t-criterion (p < 0.05), the average particle settling rate in the presence of waves differs slightly from the terminal settling velocity, which is consistent with other works. The results indicate that the average horizontal (drift) velocity follows the velocity of the mean current. The presence of wind enhances horizontal transport due to the induction of drift current and drastically increases particle dispersion.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"98 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139629086","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":"Wind waves impact on the velocity in wave boundary layer in the condition of dynamically smooth surface","authors":"K. L. Yegorov, K. Bulgakov","doi":"10.59887/2073-6673.2023.16(4)-2","DOIUrl":"https://doi.org/10.59887/2073-6673.2023.16(4)-2","url":null,"abstract":"One of the factors of wind wave impact on vertical distributions in atmosphere surface layer is the flux of momentum produced by the wave-produced fluctuations. Wave surface are supposed to be a dynamically rough and effects of the molecular viscosity are neglected. In this paper impact of wave momentum fluxes with values of wind velocity which lead to dynamically smooth ocean surface is estimated. The well-known theoretical aspects and results of experimental research are applied. Dependence of dimensionless thickness of viscosity layer on dimensionless roughness of smooth surface is analyzed. The equations of motion are formed taking into account the manifestation of three factors: molecular, turbulent and wave momentum flux. The models based on these equations are described.The choice of constant coefficients that are set in calculations with this model is considered. Results of calculations and analysis of vertical profiles of wind speed and the dependence of the drag coefficient on wind velocity under various wave age.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"31 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139535943","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":"Baroclinic factor in the stirring of waters of a sinking thermal with surrounding fresh water","authors":"A. Kupriyanova, V. A. Gritsenko","doi":"10.59887/2073-6673.2023.16(4)-1","DOIUrl":"https://doi.org/10.59887/2073-6673.2023.16(4)-1","url":null,"abstract":"The results of studying the process of stirring of a sinking thermal (small volume of denser water) with surrounding water are presented. The analysis of laboratory flows in a hydroflume has been allowed to identify the main peculiarities of the stirring of the thermal and the surrounding water. The essence of one of these features concluded in the presence of many high-gradient layers in the density field. The phase of an advective-rotational nature of the stirring of thermal waters with different density has been identified. Detailing of the evolution of the flow density structure was performed using the calculated flows on a 2d-nonlinear model of the dynamics of a fluid that is inhomogeneous in density. Features of the density structure are revealed using the values of local density gradients for the internal nodes of the computational grid. The density gradients along and across the streamlines were calculated. Quantitative estimates of the repeatability of high-gradient layers have shown significant variability in the flow density field. An analysis of the potential stability of the selected local regions of the flow has been carried out. The calculation of the Reynolds (Re) and Richardson (Ri) numbers has been allowed to assume a laminar nature of the flow, with the exception of two small zones in the back part of the sinking thermal. The role of the baroclinic mechanism of vorticity generation as a structure-forming factor in the formation of a distinguished stage of advective-vortex movement within interpenetration of thermal with surrounding water has shown.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"139 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139629528","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":"Non-self-adjoint model statement of boundary problem of acoustics. Part 1","authors":"B. A. Kasatkin, N. V. Zlobina, L. Statsenko, S. Kasatkin","doi":"10.59887/2073-6673.2023.16(2)-8","DOIUrl":"https://doi.org/10.59887/2073-6673.2023.16(2)-8","url":null,"abstract":"Based on the mathematical definition of a non-self-adjoint operator and the physical meaning of a specific boundary value problem, a non-self-adjoint model statement of boundary value problems in acoustics is formulated. As an example, boundary value problems for the reflection of a plane wave and a spherical wave at the interface between two liquid media are considered. A new definition of the reflection coefficient of a spherical wave is introduced. In the region of subcritical angles of incidence, the new definition takes into account the appearance in the total sound field of converging recoil waves corresponding to the eigenfunctions of the adjoint operator. In the region of supercritical angles of incidence, the participation of the eigenfunctions of two conjugate operators in the total sound field forms a nonzero power flux through the interface and its transformation into the vortex component of the intensity vector at the total internal reflection horizon. The definition of the total internal reflection horizon is given. Experimental data are presented that confirm the new definition of the reflection coefficient and the physical correctness of the non-self-adjoint model statement.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126704013","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":"High-Resolving modeling of the surface semidiurnal M2 tide in the East-Siberian Sea","authors":"B. Kagan, A. A. Timofeev","doi":"10.59887/2073-6673.2023.16(2)-5","DOIUrl":"https://doi.org/10.59887/2073-6673.2023.16(2)-5","url":null,"abstract":"In the framework of a high-resolving version of the 3D finite-element hydrostatic model QUODDY-4 we have simulated the fields of dynamic characteristics (amplitudes and phases of tidal elevations and barotropic tidal velocity ellipses) corresponding to the surface semidiurnal M2 tide in the no-ice East-Siberian Sea. It is shown that the obtained tidal chart has a complex structure, determined by 4 real amphidromes of left rotation which are induced by interference of counter-coming progressive Poincare waves in the southern part of the sea, 1 fake amphidrome with the center upon the Novaya Sibir Isl. and 4 small-scale amphidromes caused by interference of counter-coming Kelvin waves, from which 3 are formed in the narrow straits in the region of Bolshoy and Maly Lyahovsky Isls. and 1 near the entrance of the Chaunskaya Guba. Tidal amplitudes in the vicinity of the Novaya Sibir Isl. achieve 20–30 cm, whereas in the remaining part of the sea they are comparatively small and do not exceed 5–10 cm. Accordingly, the field of barotropic tidal velocities in the north-western part of the sea basically consists of high values (they are tens of cm/s), but in the other parts of the sea barotropic velocities are small (lower then 10 cm/s) and their field has a band structure. The fields of the averaged (over a tidal cycle) integrated in depth constituents of the barotropic tidal energy budget (namely, the barotropic tidal energy density, the advective transport and the horizontal wave flux per unit length of this energy and the rate of its dissipation due to the bottom friction) are presented. Also, a comparison of predicted tidal elevations with the mareographic level measurement data states that an estimate of their agreement may be considered as satisfactory taking into account that the tidal amplitudes in the sea as a whole are small.","PeriodicalId":218146,"journal":{"name":"Fundamental and Applied Hydrophysics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129393518","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}