Annual Variability of the Wave Regime in the Deep Zone of the Black Sea

2020 ◽  
Author(s):  
N. N. Voronina ◽  
A. S. Zapevalov ◽  
◽  
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Deep Zone ◽  
Wave Regime ◽  
Annual Variability

scholarly journals A new Diplura species from Georgia caves, Plusiocampa (Plusiocampa) imereti (Diplura, Campodeidae), with morphological and molecular data

2021 ◽  
Vol 778 ◽  
pp. 71-85
Author(s):  
Alberto Sendra ◽  
Ferran Palero ◽  
Alba Sánchez-García ◽  
Alberto Jiménez-Valverde ◽  
Jesús Selfa ◽  
...  
Keyword(s):  
New Species ◽  
Maximum Likelihood ◽  
Black Sea ◽  
Molecular Data ◽  
The Black Sea ◽  
Deep Zone ◽  
Black Sea Region ◽  
Maximum Likelihood Phylogenetic Tree ◽  
Low Altitude ◽  
Morphological And Molecular Data

A new dipluran species, Plusiocampa (Plusiocampa) imereti Sendra & Barjadze sp. nov., from the deep zone in three caves in the Imereti region, Georgia, is described. This new troglobitic Plusiocampa is an addition to four others known Diplura from around the Black Sea region, two Dydimocampa and two Plusiocampa s. str. The present study also provides the first CO1 sequences for the Plusiocampinae taxa and the first molecular data for cave-dwelling Plusiocampa species. Although bootstrap values were low, the maximum-likelihood phylogenetic tree grouped Plusiocampa (P.) imereti Sendra & Barjadze sp. nov. with two Plusiocampa s. str. species from Eastern Europe. Morphologically, P. (P.) imereti Sendra & Barjadze sp. nov. is closely related to two cave-dwelling species: Plusiocampa (Plusiocampa) glabra Condé, 1984 and Plusiocampa (P.) chiosensis Sendra & Gasparo, 2020. The new species can be distinguished by the presence of lateral anterior macrosetae on metanotum, more uneven claws, and the presence of 2+2 lateral anterior macrosetae on middle urotergites. The five species currently known for the Black Sea region inhabit caves located at low altitude but with no influence from former glacial or permafrost processes.

scholarly journals Seasonal and Inter-Annual Variability of the Phytoplankton Dynamics in the Black Sea Inner Basin

Oceans ◽  
2020 ◽  
Vol 1 (4) ◽  
pp. 251-273
Author(s):  
Svetla Miladinova ◽  
Adolf Stips ◽  
Diego Macias Moy ◽  
Elisa Garcia-Gorriz
Keyword(s):  
Black Sea ◽  
Phytoplankton Bloom ◽  
Mesoscale Eddy ◽  
Late Summer ◽  
The Black Sea ◽  
Circulation System ◽  
Nutrient Loads ◽  
Geochemical Model ◽  
Annual Variability ◽  
Intermediate Layers

We explore the patterns of Black Sea phytoplankton growth as driven by the thermohaline structure and circulation system and the freshwater nutrient loads. Seasonal and inter-annual variability of the phytoplankton blooms is examined using hydrodynamic simulations that resolve mesoscale eddies and online coupled bio-geochemical model. This study suggests that the bloom seasonality is homogeneous across geographic locations of the Black Sea inner basin, with the strongest bloom occurring in winter (February–March), followed by weaker bloom in spring (April–May), summer deep biomass maximum (DBM) (June–September) and a final bloom in autumn (October–November). The winter phytoplankton bloom relies on vertical mixing of nitrate from the intermediate layers, where nitrate is abundant. The winter bloom is highly dependent on the strength of the cold intermediate layers (CIL), while spring/summer blooms take advantage of the CIL weakness. The maximum phytoplankton transport across the North Western Shelf (NWS) break occurs in September, prior to the basin interior autumn bloom. Bloom initiation in early autumn is associated with the spreading of NWS waters, which in turn is caused by an increase in mesoscale eddy activity in late summer months. In summary, the intrusion of low salinity and nitrate-rich water into the basin interior triggers erosion of the thermocline, resulting in vertical nitrate uplifting. The seasonal phytoplankton succession is strongly influenced by the recent CIL disintegration and amplification of the Black Sea circulation, which may alter the natural Black Sea nitrate dynamics, with subsequent effects on phytoplankton and in turn on all marine life.

Wave climate in the Black Sea: description and trend evaluation using new ECMWF-ERA5 reanalysis and wave-current interaction.

2021 ◽  
Author(s):  
Salvatore Causio ◽  
Piero Lionello ◽  
Stefania Angela Ciliberti ◽  
Giovanni Coppini
Keyword(s):  
Black Sea ◽  
Wave Spectrum ◽  
Atmospheric Stability ◽  
Wave Model ◽  
Wave Climate ◽  
The Black Sea ◽  
Wave Direction ◽  
Wave Regime ◽  
Sea Temperature ◽  
Discrete Interaction

<p>This study analyzes the evolution of the wave climate in the Black Sea basin in a 31-year long hindcast (1988-2018) performed with the third-generation wave model WaveWatchIII v5.16, forced by the ECMWF-ERA5 reanalysis winds at 30km of spatial resolution and 1-hour frequency. The wave model is implemented on a grid covering the whole Black Sea, with 3km grid step and is off-line coupled with a NEMO based hydrodynamical model. The wave spectrum is discretized using 24 directional sectors, and 30 frequencies, with 10% increment starting from 0.055Hz. The model is implemented to solve deep water processes, following the WAM Cycle4 model physics, with Ultimate Quickest propagation scheme and GSE alleviation, which is implemented in WWIII. Wind input and dissipation are based on Ardhuin et al. (2010), wave-wave interactions are based on Discrete Interaction Approximation. Currents and air-sea temperature difference are provided to the wave model to account for Doppler shift and atmospheric stability above the sea. Model validation and statistical analysis have been carried out to describe the wave climate of the Black sea, considering the following wave fields: significant wave height (Hs), mean wave period (Tm) and mean wave direction. Statistics as Mean, Maximum, 5<sup>th</sup> percentile and 95<sup>th</sup> statistics have been computed to produce monthly climatologies. The work considers also the evaluation of trends for Hs and Tm, and the evaluation of tendency in the occurrence frequency of mean and max fields for Hs and Tm.</p><p>There is no evidence about an overall trend in Hs and Tm, but tendencies can be highlighted in some months and seasons. The most evident trend occurs in Summer on the whole wave spectrum, with reduction of Hs and Tm in the Eastern basin, and increasing in the South-Western basins. Even the evaluation of occurrence frequencies suggests that Black Sea is subjected to a change in the wave regime.</p>

scholarly journals Interannual Variability of the Wind-Wave Regime Parameters in the Black Sea

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
B. V. Divinsky ◽  
A. A. Kubryakov ◽  
R. D. Kosyan ◽  
◽  
◽  
...  
Keyword(s):  
Interannual Variability ◽  
Black Sea ◽  
Wind Wave ◽  
The Black Sea ◽  
Wave Regime

CLIMATIC TRENDS IN THE DYNAMICS OF MAIN CHARACTERISTICS OF THE SEA OF AZOV AND THE BLACK SEA ECOSYSTEMS

Fisheries ◽  
2020 ◽  
Vol 2020 (5) ◽  
pp. 10-15
Author(s):  
Efim Kozhurin ◽  
Evgenii Gubanov ◽  
Boris Panov ◽  
Vladimir Lanin
Keyword(s):  
Black Sea ◽  
High Probability ◽  
Climatic Changes ◽  
The Black Sea ◽  
Sea Of Azov ◽  
The Sea Of Azov ◽  
Climatic Trends ◽  
Annual Variability ◽  
Fish Productivity

The trends in climatic changes in hydrometeorological, biological, fisheries and anthropogenic characteristics of the Sea of Azov and the Black Sea ecosystems during 1980-2010 are considered. Despite the high annual variability in means of the characteristics, the significant amount of analyzed variables can be described with both linear and periodic trends. The main changes in variables considered fall on the periods of 1989-1990 and 2005-2006. The changes are explained by both natural and technogenic reasons. It is concluded, that there is a high probability of fish productivity recovery in 30th-40th of XXI century to the level of 1970th-1980th in the Sea of Azov and the Black Sea if anthropogenic impact will decrease of stabilize.

The influence of temperature on seasonal and inter-annual variability of some structural and functional characteristics of the phytoplankton in coastal waters of the Black Sea (Sevastopol region)

2019 ◽  
pp. 46-56
Author(s):  
Lyudmyla V. Stelmakh
Keyword(s):  
Growth Rate ◽  
Black Sea ◽  
Coastal Waters ◽  
Specific Growth ◽  
Seasonal Succession ◽  
The Black Sea ◽  
Species Structure ◽  
Annual Variability ◽  
Influence Of Temperature On ◽  
Phytoplankton Growth Rate

The seasonal and inter-annual variability of the phytoplankton growth rate and biomass in the coastal waters of the Black Sea near Sevastopol was studied. The nature of the seasonal dynamics and the amplitude of these parameters almost coincide. An increase in the average annual values of water temperature causes changes in the species structure of phytoplankton, its seasonal succession, and a decrease in the average annual values of the specific growth rate and phytoplankton biomass by about 2 times.

scholarly journals THE ENERGY POTENTIAL OF BLACK SEA IN ROMANIAN SEASIDE AREA

2021 ◽  
Vol 2021 (2) ◽  
pp. 27-32
Author(s):  
VALENTINA JALAN ◽  
DUMITRU DINU ◽  
RALUCA RĂDULESCU
Keyword(s):  
Black Sea ◽  
Optimal Choice ◽  
The Black Sea ◽  
Marine Geology ◽  
Energy Potential ◽  
Wave Regime ◽  
Capture Process ◽  
Energy Technologies ◽  
Free Data ◽  
Strong Winds

The Black Sea is considered a relatively calm sea, the optimal choice for the capture process is influenced by the wave regime and its peculiarities. This sea is characterized by winds that blow towards land with greater intensity in January causing the sea to be more agitated and with less power in May, June and July, when the sea was the calmest of the year. It should be noted that the frequency of strong winds is 38%, and of those of low speed of 1m/s of only 1.5%. For the collection of oceanographic and meteorological information, data provided by the Gloria platform located in front of Romania’s coast were is used, as well as records from the three offshore buoys anchored in the Romanian seaside area and which are part of the EMSO EUXINUS research infrastructure managed by National Institute for Research and Development on Marine Geology and Geoecology - GeoEcoMar. In addition, free data such as those provided by the site of the research institute Grigore Antipa were easily accessed. Presently there are three fixed platforms in the Black Sea. Wave energy is underexploited, both worldwide and in the Black Sea. The potential of this type of energy is huge, and the environmental impact is low compared to other renewable energy technologies.

scholarly journals Wave Regime and Lithodynamics in the Region of the Western Crimea Accumulative Coasts

2020 ◽  
Vol 27 (4) ◽  
Author(s):  
Yu. N. Goryachkin ◽  
V. V. Fomin ◽  
◽  
Keyword(s):  
Black Sea ◽  
Opposite Direction ◽  
Wind Waves ◽  
Reanalysis Data ◽  
The Black Sea ◽  
Wave Regime ◽  
Wave Characteristics ◽  
Convergence Zones ◽  
The Waves

Purpose. The paper is aimed at obtaining the wave regime characteristics in the region of the Western Crimea accumulative coast, at constructing the scheme of the sediment along-coastal fluxes for various wind directions, at analyzing the previous notions on the lithodynamical processes in the region under study and their comparison with the obtained results. Methods and Results. The wave regime was analyzed using the results of the retrospective calculations of wind waves in the Black Sea derived due to the model SWAN and based on the ERA-Interim atmospheric reanalysis data for 1979–2018. The data of retrospective calculations performed by the method of annual maximums yielded the parameters of the waves of various repeatability. The sediment along-coastal flux was simulated and the schemes for six wind directions were constructed by the method including model values of the wave characteristics. Conclusions. Operative and extreme characteristics of the wind waves in the region under study are obtained. It is shown that in the above-mentioned area, the most intense sediment along-coastal fluxes occur being affected by the waves formed by the western, southwestern and southern winds. The northwestern and western winds give rise to the sediment main flux directed to the east. At the western wind, to the southeast from the Donuzlav sandbar and in the coast concavities, the sediments are transported in the opposite direction. When the winds are southwestern and southern, the sediment along-coastal flux move from the Cape Uret to Lake Donuzlav northern spit, where it meets the oppositely directed flux. To the southeast from Lake Donuzlav, the multidirectional fluxes arise; at that, in the coast concavities their convergence zones are formed. At the southeastern and eastern winds, the sediment along-coastal fluxes’ capacity decreases sharply; the fluxes are of multidirectional character and they form not a single flux on any of the long stretches of the coastline.

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