The main objective of the present study is to provide a comprehensive image of the expected wind patterns along the 21st century in the Black Sea using the wind fields simulated by Regional Climate ...Model (RCM), namely Rossby Centre regional atmospheric model (version RCA4). Long‐term averages, long‐term variability, and long‐term trends in wind characteristics over the Black Sea are evaluated in two future time slices (near future 2021–2060 and middle future 2061–2100) under the two climate scenarios (RCP4.5 and 8.5). Detailed analysis of wind (annual mean and 99th percentile wind speeds) and storm characteristics (number and duration of storms) are conducted for three different locations selected on the same meridional section to assess the variability on the wind characteristics from west to east. Spatiotemporal variability on the wind characteristics indicates that the eastern Black Sea will be characterized by lower mean wind speed, stronger 99th percentile wind speed, and higher variability. Considering the global indicators of climate change (e.g., increasing frequency and intensity of extreme events), the eastern Black Sea, characterized by complex atmospheric circulation due to surrounding mountains, is more likely to be subjected to the impacts of climate change as the occurrence of extreme wind speeds in future periods is more prominent in this region. In the future periods, the 100‐year return period wind speeds increase approximately 7% and 27% in the western and eastern Black Sea, respectively, compared to the historical period. The strong and relatively stable winds with low variability in the western Black Sea indicate a reliable, persistent, and sustainable wind energy potential in this region in the future.
Study area, five selected regions for detailed RB analyses, the locations of three selected points for detailed local analyses, and wind measurement station.
This paper aims to evaluate spatiotemporal variability of the mean sea level pressure trends over the Black Sea using the gridded 40-year (1979-2018) reanalysis mean sea level pressure data from two ...different datasets. These datasets are the European Centre for Medium-Range Weather Forecasts ERA-Interim with a spatial resolution of 0.25° and temporal resolution of six hours, and the National Centers for Environmental Prediction/Climate Forecast System Reanalysis with a spatial resolution of 0.5° and temporal resolution of one hour. Data from both databases show that the mean sea level pressure tends to decrease towards the recent years over the entire Black Sea. The long-term averages of mean sea level pressure reflect the spatial variability over the Black Sea with much lower pressures in the eastern part of the Black Sea than that on the western side. The long-term variation is more intense in the eastern part of the Black Sea. Sea Level Anomaly over the Black Sea, spanning 26 years between 1993 and 2018, was analyzed using satellite altimetry data. It was found that there is a high Sea Level Anomaly where the mean sea level pressure is low, described by an inverted barometer response. The 39-year long Sea Surface Temperature Anomaly data (1981-2018) indicate the rising tendency in sea surface temperature towards recent years in the entire Black Sea. An inverse relationship is found between North Atlantic Oscillation index and sea surface temperature anomaly. On a seasonal scale, mean sea level pressure in winter (high-pressure system) is larger than that in summer (low-pressure system). Our analyses show that mean sea level pressure tends to decrease, sea surface temperature anomaly and sea surface temperature anomaly tends to increase in recent years over the Black Sea.
On 30 October 2020, a strong normal-faulting earthquake struck Samos Island in Greece and İzmir Province in Turkey, both in the eastern Aegean Sea. The earthquake generated a tsunami that hit the ...coasts of Samos Island, Greece and İzmir, Turkey. National teams performed two post-tsunami field surveys on 31 October to 1 November 2020, and 4–6 November 2020, along the Turkish coastline; while the former was a quick survey on the days following the tsunami, the latter involved more detailed measurement and investigation focusing on a ~ 110-km-long coastline extending from Alaçatı (Çeşme District of İzmir) to Gümüldür (Menderes District of İzmir). The survey teams measured runup and tsunami heights, flow depths, and inundation distances at more than 120 points at eight different localities. The largest tsunami runup among the surveyed locations was measured as 3.8 m in Akarca at a distance of 91 m from the shoreline. The maximum tsunami height of 2.3 m (with a flow depth of 1.4 m) was observed at Kaleiçi region in Sığacık, where the most severe tsunami damage was observed. There, the maximum runup height was measured as 1.9 m at the northeastern side of the bay. The survey team also investigated tsunami damage to coastal structures, noticing a gradual decrease in the impact from Gümüldür to further southeast. The findings of this field survey provide insights into the coastal impact of local tsunamis in the Aegean Sea.
Rubble mound breakwaters usually consist of armour, filter and core layers. The units used in the armour layer are natural rock or concrete. Although natural rock is usually preferred, it is not ...always possible to apply it. There are some advantages to using concrete units: they have a high stability coefficient under wave attack, and they are easily produced at work sites. Tetrapod and cube blocks are widely used in breakwaters as armour units.
Rubble mound breakwaters are subjected not only to wave activity but also other types of environmental loading, such as earthquakes. Although rubble-mound breakwaters are most likely the most common type of breakwaters, they have received little attention regarding their response to seismic activity. The objective of this study is to present the dynamic response of a breakwater armoured by tetrapods placed by two different placement methods and armoured by cubes during seismic loadings experimentally and numerically. A shaking tank was developed for the experimental study. The breakwater models sit on a rigid bed, and the model scale is 1/50. A one-dimensional shaking tank was used to understand simple responses of the rubble mound breakwaters under seismic loads. The tank allows only one degree of freedom. A raining crane system was developed to achieve the same packing density and porosity for the core material. The shape of the model breakwater before and after the tests was measured using a profiler and was recorded by computer. However, crest lowering and the level of damage on slopes were determined from profiler records. The dynamic responses of the model breakwaters were also investigated using an image processing technique. For numerical simulation, software using finite element method was used.
The results obtained from the experiment and numerical model may help designers build breakwaters armoured by artificial units.
•The dynamic response of a breakwater with tetrapods placed using two different placement methods and cube blocks was modelled experimentally and numerically.•Software that solves the problem using finite element methods (FEMs) was used.•The material properties of the tetrapod and cube blocks were determined by numerical simulation.•FEM and experimental results were compared.
The present study evaluates future wave power resources and detects a possible impact of climate change on wave power in an enclosed sea (Black Sea) for the 21st century. The wave data are obtained ...from a third-generation spectral wave model using a validated RCM (Regional Climate Model). The wave power projection and projected occurrences are analyzed for near and middle future (NF, MF) periods based on two RCP (Representative Concentration Pathway) scenarios (4.5 and 8.5). Possible changes in wave power for the NF 2021–2060 and MF 2061−2100 periods are evaluated by comparing the historical (1970–2005) period. According to two RCP scenarios, the wave power potential for the NF is expected to increase markedly over the entire basin, while, for the MF, the changes are projected by decreases, especially in the northeastern and western parts of the basin. Furthermore, projected occurrences are examined using Energy Level Occurrences known as available, moderate, and rich level occurrences. The 15 reference points over the basin are chosen to detect the most suitable location(s) for future wave power developments. All spatial and local analyses indicate that the western basin, especially the southwest, will continue having high wave power potential and occurrences in future periods.
•Evaluation of future wave energy and detection of a possible climate change impact on wave power for the 21st century.•Long-term and seasonal averages of wave power and future changes are examined in two future periods for two RCP scenarios.•15 points covering the Black Sea are analyzed to detect the most suitable location(s) for future developments of wave power.
This study aimed to evaluate the possible impacts of climate change on the wind power potential and assign possible stable locations in the Black Sea until the end of the 21st century. The wind ...fields simulated by a regional climate model (Rossby Centre regional atmospheric climate model, version RCA4) were analyzed considering two future periods (2021–2060, 2061–2100) under RCP4.5 and RCP8.5 scenarios. The temporal variability of the wind power density (WPD) was investigated using both spatial and local analyses for the future period (2021–2100). Three temporal variability indices (namely the coefficient of variation (CV), monthly (MV), and seasonal variability (SV)) were in agreement that the mean WPD in the eastern basin is significantly more variable than in other parts of the basin. Considering the impact of climate change, the future projections for both climate scenarios indicate changes, and the eastern basin will experience more changes under the RCP8.5 scenario. For the most predictable future developments of the wind power potential, 15 reference points along the Black Sea were analyzed using the intra- and inter-annual variability of the mean WPD. In the future, strong, durable, and stable wind resources in the western basin will ensure reliable, permanent, and sustainable WPD.
•The present study aims to provide a comprehensive analyses of the expected wind power potential and their variability under possible future climatic conditions for the 21st century.•This study presents the possible locations to develop future wind farm plans in the Black Sea.
•A long-term comparative assessment of the potential of wave power in the Black Sea was conducted using the SWAN model forced by two well-known wind fields.•This study highlights the importance of ...correct identification of the mean wave power, which is crucial for the implementation of proper WECs.•The long-term and seasonal averages of the wave power and their variabilities over the entire Black Sea were investigated, and some local points were analyzed in detail.
In this study, a long-term comparative assessment of the potential of wave power in the Black Sea was conducted using the calibrated and validated SWAN (Simulating WAves Nearshore) model forced by two well-known wind fields. The European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim and National Centers for Environmental Prediction/Climate Forecast System Reanalysis (NCEP/CFSR) wind fields were used, covering data from 1979 to 2018. In general, the wave power potential based on the results of the CFSR wind field was found to be slightly higher than that obtained with the ERA-Interim wind field. The greatest discrepancy between the results of the ERA-Interim and CFSR wind fields was observed in the northeastern Black Sea. The spatial distributions of the wave power were also evaluated on a seasonal scale using wave parameters obtained from the calibrated SWAN model. The wave climate obtained from both long-term and seasonal assessments indicates that the western Black Sea, especially the southwestern Black Sea, is characterized by higher wave power potential and lower variability, while the eastern Black Sea has lower wave power potential and higher variability. Stable and powerful long-term wave conditions in the southwestern Black Sea can indicate that this region is a suitable location for wave farms. In contrast, the effect of the long-term variability on wave power is greatest in the eastern Black Sea owing to the highly variable wave conditions in this region.
This study aims to examine the temporal and spatial variability of mean sea level pressure (MSLP) and to determine the relationship between MSLP and the oceanic data, such as sea surface temperature ...(SST), and sea level anomaly (SLA). The long-term and decadal averages, long-term trends, and their statistical significance levels were evaluated in the eastern Mediterranean and Black seas as enclosed sea examples. In the Black Sea, the western part was exposed to higher MSLP accompanied by relatively low sea level rise compared to the eastern part of the sea. In the eastern Black Sea, significant sea level rise was detected, where the MSLP was low due to the inverse barometer (IB) effect. In the eastern Mediterranean Sea, MSLP was significantly decreased eastward and was accompanied by relatively high sea level rise compared to other parts of the basin. The highest MSLP was found in the Aegean Sea, where the sea level rise was relatively low. In recent years, significant warming tendency in SST triggers a significant decreasing trend in MSLP and the rising tendency in sea level over the eastern Mediterranean and Black seas.
Long-term water level data with 15-minute temporal resolution from 18 tide gauge stations were used to analyze tidal and non-tidal oscillations in four different seas along the Turkish coasts. ...High-resolution spectral analysis revealed that the semi-diurnal peaks (M2, N2, S2, K2) were higher than diurnal (O1, P1, S1, K1) in the enclosed basins: the Black, Aegean, and Levantine Seas. In the inland basin (the Sea of Marmara), however, both diurnal and mixed but mainly semi-diurnal tides were observed. Tidal ranges are the smallest in the Sea of Marmara as the basin is not large enough to generate its tide. In addition to this, the two narrow and shallow straits connecting it to the larger water bodies isolate this sea from the tidal forcing of two larger water bodies. The second smaller diurnal and semi-diurnal tidal amplitudes were observed in the Black Sea. Both it is an enclosed water body and meteorologically and hydrologically (river inflow and precipitation) the most active water body among all, the tide is masked by this these water level oscillations. Generally, there was an increasing trend in the average water level from fall to early summer corresponding to the hydrologically active period. The annual solar radiational harmonics (SA), which were in the range of 5 to 10 cm, were observed in the whole considered seas while semiannual (SSA,) harmonics, which were in the ranges smaller than 5 cm, were only observed in the Black and the Levantine Seas. The tide is minimum (∼O(10 cm)) in the Sea of Marmara and maximum in the Levantine Sea ((∼O(40–50 cm)). The contribution of the tidal harmonics to the water level energy is around one-half-fold of non-tidal ones in the easternmost part of the Levantine Sea. The largest water level ranges around 100 to 150 cm, however, observed over short periods (day to a week) due to severe meteorological conditions.
•The water levels were analyzed in three enclosed and one inland sea basin.•The water levels are composed the regular (tidal) and irregular (non-tidal) components.•Non-tidal components are predominant in the least large enclosed basin and inland basin.•Tide is predominant in the water levels of the largest enclosed basin.•The main lunar semidiurnal harmonic (M2) is the largest harmonic among all.
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