scholarly journals The impact of various types of open boundary conditions in numerical simulation of the Black Sea coastal circulation

2019 ◽  
Vol 386 ◽  
pp. 012024
Author(s):  
M V Senderov
Keyword(s):  
Numerical Simulation ◽  
Boundary Conditions ◽  
Black Sea ◽  
Open Boundary ◽  
The Black Sea ◽  
Open Boundary Conditions ◽  
Coastal Circulation ◽  
The Impact

Tools and technologies for NEMO models: the case of the Generic Interfaces developed in the framework of IMMERSE

2021 ◽  
Author(s):  
Laura Stefanizzi ◽  
Stefania Ciliberti ◽  
Mehmet Ilicak ◽  
Giovanni Coppini
Keyword(s):  
Boundary Conditions ◽  
Black Sea ◽  
Numerical Solutions ◽  
Initial Boundary ◽  
Coastal Ocean ◽  
Open Boundary ◽  
The Black Sea ◽  
Marmara Sea ◽  
Open Boundary Conditions ◽  
Model Configuration

<p>Setting new model configurations based on NEMO requires the definition of initial/boundary condition and the validation of numerical solutions. In the framework of IMMERSE H2020 project, CMCC is developing new tools and technological capacities for handling in easy and reliable way external products, such CMEMS or coastal ocean data, for research-to-operations applications. Generic Interfaces for NEMO (InterNEMO) allow for 3 main scopes: 1) to access and discover the CMEMS catalogue, including both model and observational data; 2) to manipulate accessed datasets, including coastal ocean data, to extract relevant physical information to use for setting initial/boundary conditions for a new NEMO-based configurations; 3) to prepare NEMO set of upstream files and to validate NEMO solution by using CMEMS observational datasets. InterNEMO implements also technologies to connect a NEMO user to Wekeo DIAS (https://www.wekeo.eu/) for the interoperable accessing and processing of CMEMS data. In this contribution, we present the InterNEMO architecture developed in Python via Jupyter Notebooks, to support the user/researcher to easily discover, design and configure modeling components required by the new NEMO-based configuration. InterNEMO is tested for the Black Sea hydrodynamical model configuration, developed by CMCC in the framework of the Black Sea Monitoring and Forecasting Centre (BS-MFC) for CMEMS a) to show how to access CMEMS observations through Wekeo DIAS and use them to validate numerical solutions and b) to define open boundary conditions from an unstructured grid model configuration based on Shyfem, developed for the Marmara Sea.</p>

scholarly journals Generation of Vertical Fine Structure by the Internal Waves with the Regard for Turbulent Viscosity and Diffusion

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
S. G. Demyshev ◽  
N. A. Evstigneeva ◽  
D. V. Alekseev ◽  
O. A. Dymova ◽  
N. A. Miklashevskaya ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Data Assimilation ◽  
Potential Energy ◽  
Black Sea ◽  
Anticyclonic Eddy ◽  
Shear Instability ◽  
Optimal Interpolation ◽  
Open Boundary ◽  
The Black Sea ◽  
Coastal Circulation

Purpose. The study is aimed at evaluating effectiveness of the procedure of the observational data assimilation using the Kalman filter algorithm as compared to sequential analysis of the hydrophysical fields based on the optimal interpolation method, and at analyzing the mesoscale features of coastal circulation near the western Crimea coast and in the Sevastopol region. Methods and Results. Based on the hydrodynamic model adapted to the Black Sea coastal zone conditions including the open boundary and on the temperature and salinity data from the hydrological survey in 2007, the dynamic and energy characteristics of the Black Sea coastal circulation were calculated with high spatial resolution (horizontal grid is ~ 1.6 × 1.6 km and 30 vertical horizons). The hydrophysical fields were reconstructed using two algorithms of data assimilation: the sequential optimal interpolation and the modified Kalman filter. The kinetic energy changed mainly due to the wind action, vertical friction and the work of pressure forces; the potential energy – due to the potential energy advection and the horizontal turbulent diffusion. The following circulation features were reconstructed: the anticyclonic eddy with the radius about 15 km in the Kalamita Bay in the water upper layer, the anticyclonic eddy with the radius about 15 km between 32.2 and 32.6° E in the whole water layer, the intense current near Sevastopol and along the Crimea western coast directed to the north and northwest, and the submesoscale eddies of different signs of rotation in the upper layer. Conclusions. It is shown that having been taken into account, heterogeneity and non-isotropy of the error estimates of the temperature and salinity fields relative to the correlation function lead to qualitative and quantitative differences in the hydrodynamic fields (amplification of currents, change of the currents’ direction and eddy formations were better pronounced). At the same time, the mean square errors of the thermohaline fields’ estimates decreased. Formation of the anticyclonic eddy with the radius about 15 km in the Kalamita Bay could be related to the current shear instability. Submesoscale eddies with the diameters less than 5 km were formed when the current flowed around the coastline and the bottom topography inhomogeneities.

scholarly journals A Model of Black Sea Circulation with Strait Exchange (2008–2018)

2019 ◽  
Author(s):  
Murat Gunduz ◽  
Emin Özsoy ◽  
Robinson Hordoir
Keyword(s):  
Black Sea ◽  
Lower Layer ◽  
Circulation Model ◽  
Open Boundary ◽  
The Black Sea ◽  
Marmara Sea ◽  
Open Boundary Conditions ◽  
Medium Resolution ◽  
Water Mass Formation ◽  
High Space

Abstract. The Bosphorus exchange is of critical importance for hydrodynamics of the Black Sea. In this study, we report on the development of a medium resolution circulation model of the Black Sea, making use of up-to-date topography, atmospheric forcing with high space and time resolution, climatic river fluxes and strait exchange enabled by adding the Bosphorus Strait with an artificial box on the Marmara Sea side. Particular attention is given to circulation, mixing, convective water mass formation processes compared with observations. The present formulation with temperature and salinity relaxed to the observed seasonal climatology of the Marmara box and open boundary conditions are found to enable Bosphorus exchange with upper, lower layer and net fluxes comparable to the observed range. This in turn enables to capture the trend of rapid climatic change observed in the Black Sea in the last decade.

scholarly journals A model of Black Sea circulation with strait exchange (2008–2018)

2020 ◽  
Vol 13 (1) ◽  
pp. 121-138 ◽  
Author(s):  
Murat Gunduz ◽  
Emin Özsoy ◽  
Robinson Hordoir
Keyword(s):  
Black Sea ◽  
Lower Layer ◽  
Climatic Variability ◽  
Circulation Model ◽  
Open Boundary ◽  
The Black Sea ◽  
Marmara Sea ◽  
Open Boundary Conditions ◽  
Medium Resolution ◽  
High Space

Abstract. The Bosphorus exchange is of critical importance for hydrodynamics and hydroclimatology of the Black Sea. In this study, we report on the development of a medium-resolution circulation model of the Black Sea, making use of surface atmospheric forcing with high space and time resolution, climatic river fluxes and strait exchange, enabled by adding elementary details of strait and coastal topography and seasonal hydrology specified in an artificial box on the Marmara Sea side. Particular attention is given to circulation, mixing and convective water mass formation processes in the model, which are then compared with observations. Open boundary conditions relaxed to seasonal hydrology specified in the artificial box are found to enable Bosphorus exchange with a proper upper layer, lower layer and net fluxes comparable to the observed ranges. These improvements at the artificial boundary and in the interior evolution of the Black Sea allow the study to capture daily, seasonal to decadal climatic variability and change observed in the Black Sea in the last few decades.

scholarly journals Multi-Criteria Analysis of the Mass Tourism Management Model Related to the Impact on the Local Community in Constanta City (Romania)

Inventions ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 46
Author(s):  
Catalin Anton ◽  
Angela-Eliza Micu ◽  
Eugen Rusu
Keyword(s):  
Black Sea ◽  
Seasonal Cycle ◽  
Local Community ◽  
Local Economy ◽  
Management Model ◽  
The Black Sea ◽  
Mass Tourism ◽  
Tourism Management ◽  
The Impact ◽  
The City

Traditionally and socially, the tourism in Constanta is considered to be important to the local economy. Sun and beach locations are both a draw for locals and tourists to the city, on the Black Sea. However, vacation-oriented activities in the city only have a seasonal cycle. In this paper, we proposed to analyze the mass tourist activity in Constanta, taking into account economic, social, and environmental conditions. Additionally, we attempted to build a model based on the data available. The model was developed using a PESTEL analysis to determine the supportability factor of the indicators identified. We also set out to create a projection of the activities proposed for analysis by 2050. To create a model for coastal areas, the data used in this research must be accurate and consistent. Furthermore, correctly identifying indicators and their relationships is a critical step in conducting a thorough study. Last but not least, finding the calculation coefficient for the activity in question is critical, as collecting data from various activities might be challenging when trying to find a feasible model.

scholarly journals Impurity induced scale-free localization

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Linhu Li ◽  
Ching Hua Lee ◽  
Jiangbin Gong
Keyword(s):  
Boundary Conditions ◽  
Skin Effect ◽  
Reciprocal Lattice ◽  
Periodic Boundary Conditions ◽  
Open Boundary ◽  
Open Boundary Conditions ◽  
Translational Invariance ◽  
Scale Free ◽  
Special Cases ◽  
Simulation Results

AbstractNon-Hermitian systems have been shown to have a dramatic sensitivity to their boundary conditions. In particular, the non-Hermitian skin effect induces collective boundary localization upon turning off boundary coupling, a feature very distinct from that under periodic boundary conditions. Here we develop a full framework for non-Hermitian impurity physics in a non-reciprocal lattice, with periodic/open boundary conditions and even their interpolations being special cases across a whole range of boundary impurity strengths. We uncover steady states with scale-free localization along or even against the direction of non-reciprocity in various impurity strength regimes. Also present are Bloch-like states that survive albeit broken translational invariance. We further explore the co-existence of non-Hermitian skin effect and scale-free localization, where even qualitative aspects of the system’s spectrum can be extremely sensitive to impurity strength. Specific circuit setups are also proposed for experimentally detecting the scale-free accumulation, with simulation results confirming our main findings.

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