scholarly journals Numerical modelling of the Caspian Sea tides

Ocean Science ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 209-219
Author(s):  
Igor P. Medvedev ◽  
Evgueni A. Kulikov ◽  
Isaac V. Fine
Keyword(s):  
Caspian Sea ◽  
Ocean Model ◽  
Tidal Range ◽  
The South ◽  
Tidal Dynamics ◽  
The Caspian Sea ◽  
Sea Levels ◽  
The North ◽  
Anticlockwise Rotation ◽  
Diurnal Tides

Abstract. The Caspian Sea is the largest enclosed basin on Earth and a unique subject for the analysis of tidal dynamics. Tides in the basin are produced directly by the tide-generating forces. Using the Princeton Ocean Model (POM), we examine details of the spatial and temporal features of the tidal dynamics in the Caspian Sea. We present tidal charts of the amplitudes and phase lags of the major tidal constituents, together with maps of the form factor, tidal range, and tidal current speed. Semi-diurnal tides in the Caspian Sea are determined by a Taylor amphidromic system with anticlockwise rotation. The largest M2 amplitude is 6 cm and is located in Türkmen Aylagy (called Turkmen Bay hereafter). For the diurnal constituents, the Absheron Peninsula separates two individual amphidromes with anticlockwise rotation in the north and in the south. The maximum K1 amplitudes (up to 0.7–0.8 cm) are located in (1) the south-eastern part of the basin, (2) Türkmenbaşy Gulf, (3) Mangyshlak Bay; and (4) Kizlyar Bay. As a result, the semi-diurnal tides prevail over diurnal tides in the Caspian Sea. The maximum tidal range, of up to 21 cm, has been found in Turkmen Bay. The strongest tidal currents have been located in the straits to the north and south of Ogurja Ada, where speeds reach 22 and 19 cm s−1, respectively. Numerical simulations of the tides using different mean sea levels (within a range of 5 m) indicate that spatial features of the Caspian Sea tides are strongly sensitive to changes in mean sea level.

scholarly journals Numerical modelling of the tides in the Caspian Sea

2019 ◽  
Author(s):  
Igor Medvedev ◽  
Evgueni Kulikov ◽  
Isaac Fine
Keyword(s):  
Caspian Sea ◽  
Numerical Experiments ◽  
Ocean Model ◽  
Tidal Currents ◽  
Tidal Range ◽  
Tidal Dynamics ◽  
The Caspian Sea ◽  
Southeastern Part ◽  
Counterclockwise Rotation ◽  
The North

Abstract. The Caspian Sea is the largest enclosed basin on the Earth and a unique object for analysis of tidal dynamics. The Caspian Sea has independent tides only, which are generated directly by tide-forming forces. Based on the Princeton Ocean Model (POM) the spatial and temporal features of tidal dynamics in the Caspian Sea were described in detail. Detailed tidal charts for amplitudes and phase lags of the major tidal harmonics, form factor, tidal range and velocity of tidal currents were plotted. Semidiurnal tides in the Caspian Sea are determined by a Taylor amphidromic system with counterclockwise rotation. The largest M2 amplitude is 6 cm and is located in the Turkmen Bay. The Absheron Peninsula splits this system into two separate amphidromies with counterclockwise rotation to the north and to the south of it. The maximum K1 amplitudes (up to 0.7–0.8 cm) are located in: (1) the southeastern part of the Caspian Sea, (2) the Türkmenbaşy Gulf, (3) the Mangyshlak Bay, and (4) the Kizlyar Bay. The semidiurnal tides prevail over diurnal tides in the Caspian Sea. The maximum tidal range has been observed in the Turkmen Bay, up to 21 cm. The highest velocity of the total tidal currents is observed in the straits to the north and south of Ogurja Ada, up to 22 cm/s and 19 cm/s, respectively. Were made numerical experiments with tidal simulation using different mean sea level MSL of the Caspian Sea (from −25 m to −30 m). Numerical experiments indicate that the spatial features of tides are strongly sensitive to the MSL changes.

scholarly journals Spatio-temporal variability of organic matter contents in the waters of the Caspian Sea

2019 ◽  
Vol 46 (1) ◽  
pp. 70-81
Author(s):  
A. I. Agatova ◽  
N. I. Torgunova ◽  
E. A. Serebryanikova ◽  
L. K. Dukhova
Keyword(s):  
Organic Matter ◽  
Hydrogen Sulfide ◽  
Caspian Sea ◽  
Vertical Mixing ◽  
Qualitative Change ◽  
Border Region ◽  
The Caspian Sea ◽  
Sea Levels ◽  
The North ◽  
Spatio Temporal

We analyzed spatio-temporal changes in concentrations and elemental compositions of dissolved organic matter in the waters of the Caspian Sea over the period 2010–2015. These studies showed that over the past 5 years of lowering of sea levels, mean concentrations of Corg and Norg remained virtually unchanged, whereas concentrations of Porg decreased more than three-fold, suggesting a qualitative change in organic matter. Based on data averages, concentrations of Corg, Norg, and Porg in Southern waters were slightly higher than in the North and Middle-Caspian waters during the monitoring period. In deep areas at the border region of hydrogen sulfide occurrence, concentrations of Corg, Norg, and Porg increase. Hence, the presence of hydrogen sulfide in the deep waters of the Derbent and South Caspian basins, and the corresponding increase in organic matter contents, indicates no radical improvement of vertical mixing of the sea in these areas during the eight years of our regression model. Moreover, according to the carbohydrate distribution, organic substances of petroleum hydrocarbons contribute considerably to a common pool.

scholarly journals Natural-climatic Conditions of Salyan Plain

2020 ◽  
Vol 6 (3) ◽  
pp. 222-225
Author(s):  
A. Jafarova
Keyword(s):  
Caspian Sea ◽  
Climatic Conditions ◽  
Recent Past ◽  
The South ◽  
The Caspian Sea ◽  
The West ◽  
The North

The Salyan plain is the smallest of the 5 plains of the Kur-Araz lowland. Salyan Plateau was formed in the recent past as a result of the withdrawal of the Caspian Sea. The Salyan plain borders on the Akkusha River in the west, the Caspian Sea in the east, the Kur River in the north, and Kyzylagach Bay in the south and covers an area of 149,000 ha. The article provides information about the relief of the Salyan plain, climate, soil and vegetation.

ICE CONDITIONS IN THE NORTH-WESTERN PART OF THE CASPIAN SEA IN THE MODERN PERIOD

2020 ◽  
Vol 19 (6) ◽  
pp. 4-17
Author(s):  
Nepomenko Leonid ◽  
◽  
Popova Natalia ◽  
Zubanov Stepan ◽  
Ostrovskaya Elena ◽  
...  
Keyword(s):  
Caspian Sea ◽  
The Caspian Sea ◽  
The North ◽  
Modern Period ◽  
Ice Conditions ◽  
North Western

scholarly journals The length of coastlines in Ptolemy's Geography and in ancient periploi

2018 ◽  
Vol 9 (1) ◽  
pp. 9-24 ◽  
Author(s):  
Dmitry A. Shcheglov
Keyword(s):  
Caspian Sea ◽  
Simple Explanation ◽  
The Caspian Sea ◽  
The North ◽  
True Value ◽  
The Earth ◽  
Erroneous Estimate ◽  
Remarkable Agreement ◽  
East West

Abstract. The lengths of the coastlines in Ptolemy's Geography are compared with the corresponding values transmitted by other ancient sources, presumably based on some lost periploi (literally "voyages around or circumnavigations", a genre of ancient geographical literature describing coastal itineraries). The comparison reveals a remarkable agreement between them, suggesting that Ptolemy relied much more heavily on these or similar periploi than it used to be thought. Additionally, a possible impact of Ptolemy's erroneous estimate of the circumference of the Earth is investigated. It is argued that this error resulted in two interrelated distortions of the coastal outlines in Ptolemy's Geography. First, the north–south stretches of the coast that were tied to particular latitudes are shown compressed relative to the distances recorded in other sources in roughly the same proportion to which Ptolemy's circumference of the Earth is underestimated relative to the true value. Second, in several cases this compression is compensated by a proportional stretching of the adjacent east–west coastal segments. In particular, these findings suggest a simple explanation for the strange shape of the Caspian Sea in Ptolemy's Geography.

scholarly journals Mental health services in Azerbaijan

2004 ◽  
Vol 1 (3) ◽  
pp. 16-17
Author(s):  
Fuad Ismayilov
Keyword(s):  
Mental Health ◽  
Soviet Union ◽  
Mental Health Services ◽  
Health Services ◽  
Caspian Sea ◽  
Total Population ◽  
The Other ◽  
The Caspian Sea ◽  
The North ◽  
The Soviet Union

Azerbaijan is a nation with a Turkic population which regained its independence after the collapse of the Soviet Union in 1991. It has an area of approximately 86 000 km2. Georgia and Armenia, the other countries comprising the Transcaucasian region, border Azerbaijan to the north and west, respectively. Russia also borders the north, Iran and Turkey the south, and the Caspian Sea borders the east. The total population is about 8 million. The largest ethnic group is Azeri, comprising 90% of the population; Dagestanis comprise 3.2%, Russians 2.5%, Armenians 2% and others 2.3%.

scholarly journals Geothermal field and geology of the Caspian Sea region

2019 ◽  
pp. 104-118 ◽  
Author(s):  
Vladimir I. Zui ◽  
Siamak Mansouri Far Far
Keyword(s):  
Heat Flow ◽  
Flow Pattern ◽  
Caspian Sea ◽  
Sedimentary Basins ◽  
Geothermal Field ◽  
Flow Density ◽  
General Tendency ◽  
The Caspian Sea ◽  
Northern Iran ◽  
The North

The Caspian Sea and adjacent areas form the vast oil and gas-bearing megabasin. It consists of North Caspian, Middle Caspian, and South Caspian sedimentary basins. The granite-metamorphic basement of the basins becomes from north to south younger in the direction from Early Precambrian to Early Cimmerian age. It represents a transitional zone from the southern edge of the East European Craton to Alpine folding. Geothermal investigations have been carried out both in hundreds of deep boreholes and within the Caspian Sea and a few preliminary heat flow maps were published for the Caspian Sea region. All they excluded from consideration the southern part of the region within Iranian national borders. We prepared a new heat flow map including the northern Iran. The purpose of the article is to consider heat flow pattern within the whole Caspian Sea region including its southern part. Two vast high heat flow anomalies above 100 mW/m2 distinguished in the map: within the southwestern Iran and in waters of the Caspian Sea to the North of the Apsheron Ridge, separated by elongated strip of heat flow below 50 –55 mW/m 2 . A general tendency of heat flow from growing was distinguished from the Precambrian crustal blocks of the North Caspian Depression to the Alpine folding within the territory of Iran. Analysis of the heat flow pattern is discussed and two heat flow density profiles were compiled.

Numerical Study on Circulation and Thermohaline Structures With Effects of Icing Event in the Caspian Sea

2010 ◽  
Author(s):  
Daisuke Kitazawa ◽  
Jing Yang
Keyword(s):  
Numerical Simulation ◽  
Water Temperature ◽  
Coriolis Force ◽  
Caspian Sea ◽  
Numerical Study ◽  
Measurement Data ◽  
Ocean Model ◽  
Water Current ◽  
The Caspian Sea ◽  
Volga River

A hydrostatic and ice coupled model was developed to analyze circulation and thermohaline structures in the Caspian Sea. The northern part of the Caspian Sea freezes in the winter. Waters start icing in November and ices spread during December and January. The northern part of the Caspian Sea is covered by ices in severe winters. Ice-covered area is at its maximum during January and February, and then ices begin melting in March and disappear in April. The occurrence of ices must have significant effects on circulation and thermohaline structures as well as ecosystem in the northern Caspian Sea. In the present study, formation of ices is modeled assuming that ices do not move but spread and shrink on water surface. Under the ices, it is assumed that the exchange of momentum flux is impeded and the fluxes of heat and brine salt are given at sea-ice boundary. The ice model was coupled with a hydrostatic model based on MEC (Marine Environmental Committee) Ocean Model developed by the Japan Society of Naval Architect and Ocean Engineers. Numerical simulation was carried out for 20 years to achieve stable seasonal changes in current velocity, water temperature, and salinity. The fluxes of momentum, heat, and salt were estimated by using measurement data at 11 meteorological stations around the Caspian Sea. Inflow of Volga River was taken into account as representative of all the rivers which inflow into the Caspian Sea. Effects of icing event on circulation and thermohaline structures were discussed using the results of numerical simulation in the last year. As a result, the accuracy of predicting water temperature in the northern Caspian Sea was improved by taking the effects of icing event into account. Differences in density in the horizontal direction create several gyres with the effects of Coriolis force. The differences were caused by differences in heat capacity between coastal and open waters, differences in water temperature due to climate, and inflow of rivers in the northern Caspian Sea. The water current field in the Caspian Sea is formed by adding wind-driven current to the dominant density-driven current, which is based on horizontal differences in water temperature and salinity, and Coriolis force.

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