Prediction of Caspian Sea Level Fluctuations Using Artificial Intelligence

2012 ◽  
Vol 9 (11) ◽  
pp. 16663-16704
Author(s):  
S. A. G. Leroy ◽  
H. A. K. Lahijani ◽  
J.-L. Reyss ◽  
F. Chalié ◽  
S. Haghani ◽  
...  

Abstract. We analysed dinoflagellate cyst assemblages in four short sediment cores, two of them dated by radionuclides, taken in the south basin of the Caspian Sea. The interpretation of the four sequences is supported by a collection of 27 lagoonal or marine surface sediment samples. A sharp increase in the biomass of the dinocyst occurs after 1967, especially owing to Lingulodinium machaerophorum. Considering nine other cores covering parts or the whole of Holocene, this species started to develop in the Caspian Sea only during the last three millennia. By analysing instrumental data and collating existing reconstructions of sea level changes over the last few millennia, we show that the main forcing of the increase of L. machaerophorum percentages and of the recent dinocyst abundance is global climate change, especially sea surface temperature increase. Sea level fluctuations likely have a minor impact. We argue that the Caspian Sea has entered the Anthropocene.


2016 ◽  
Vol 408 ◽  
pp. 52-64 ◽  
Author(s):  
Elias Ramezani ◽  
Almut Mrotzek ◽  
Mohammad Reza Marvie Mohadjer ◽  
Ata Abdollahi Kakroodi ◽  
Salomon B. Kroonenberg ◽  
...  

2020 ◽  
Vol 3 ◽  
pp. 42-57
Author(s):  
A.V. Pavlova ◽  
◽  
V.S. Arkhipkin ◽  
S.A. Myslenkov ◽  
◽  
...  

The article presents the results of hydrodynamic modeling of sea level fluctuations in the Caspian Sea using the ADCIRC model for the period from 1979 to 2017. Surges are simulated using an irregular triangulation computational grid with a changing cell size, that easily adapts to changes in shoreline and depth and, therefore, more accurately describes coastal zones. It is found that the seasonal variability of surges is characterized by a maximum in winter and spring and by a minimum in summer. On the western coast of the North Caspian Sea, the maximum sea-level fluctuations are observed in December-February, and on the northern and eastern coasts – in February and March. The areas of inundation of the coastal territory of the Russian sector of the sea are identified. For the surge on March 12–16, 1995, that was one of the most catastrophic ones in terms of its consequences, the inundation area made up 53% of the possible flooded area, and the inundation area for the surge registered on March 27–April 1, 2015 made up 71 %. The more severe consequences of the surge in 1995 are associated with the fact that the mean annual sea level, that determines the possible flooded area, in 1995 was much higher than in 2015. Keywords: ADCIRC, Caspian Sea, unstructured grid, storm surge, sea level, numerical modeling Fig. 11. Ref. 15.


2019 ◽  
pp. 27-39
Author(s):  
G. I. Rychagov

The main focus of the article is the significance of the geomorphological method for the reconstruction of paleogeographic events that took place in the Late Pleistocene and Holocene. The specific data obtained as a result of applying this method are given. A reasonable curve of the Caspian Sea level fluctuations in the Holocene was compiled. A risk zone has been defined, within which the level of the Caspian Sea will fluctuate in the future, under modern physics-geographical conditions, which is fundamental importance when planning any economic measures in the coastal zone. Predictions were made and later justified of the Caspian Sea level fluctuations in the 20thearly 21st centuries. The climatic nature of the Caspian transgressions was confirmed. Obtained were new data on the evolution of the shores of the Caspian Sea under rising level conditions, which can be used when forecasting the development of the shores of other seas in the conditions of the present-day rise of the World Ocean level.


Radiocarbon ◽  
1993 ◽  
Vol 35 (3) ◽  
pp. 409-420 ◽  
Author(s):  
Yu. A. Karpytchev

Owing to the large basin area of the Caspian Sea, fluctuations in its level reflect climatic changes in the northern hemisphere. To reconstruct these fluctuations, I collected mollusk shells, plant debris, carbonates and organic matter samples for 14C dating from deposits of ancient salt marshes, depressions and bars formed during significant sea-level decline. I studied the impact of eolian sedimentation via parallel dating of carbonates and other materials. The data demonstrate that sea level rises during periods of cooling and falls during warming periods; this is true for both long-term (2–2.5 ka) and short-term climatic changes.


2013 ◽  
Vol 51 (5) ◽  
pp. 858-873 ◽  
Author(s):  
M.A. Sharifi ◽  
E. Forootan ◽  
M. Nikkhoo ◽  
J.L. Awange ◽  
M. Najafi-Alamdari

2019 ◽  
Vol 47 (5) ◽  
pp. 130-148 ◽  
Author(s):  
A. V. Frolov

The paper deal with the scenario method for predicting long-term fluctuations in the Caspian Sea level. The scenario forecasts are included: Model of the sea level fluctuations mechanism, Models of the main components of the sea water balance, Morphometric characteristics of sea, Dependence between the outflow of water into the Kara-Bogaz-Gol Bay and the sea level, Assessments of possible direct technogenic impacts on the sea water balance, for example, the withdrawals of water from the inflow into the sea. The Caspian Sea level long-term fluctuations are considered by us as the output process of a non-linear hydrological system. The mechanism of the Caspian level fluctuations contains two negative and one positive feedback. The dependences of the Caspian sea area and the outflow from the sea into the Kara-Bogaz-Gulf bay on the sea level form negative feedbacks. Positive feedback is formed by the nonlinear dependence of evaporation from the sea area on the sea level. Under certain conditions, the effect of this dependence can lead to the sea level bimodal probability distribution density. A necessary (but not sufficient) condition for bimodality is the absence of free seawater inflow from the sea into Kara-Bogaz-Gol. The results of scenario forecasts of the Caspian Sea level developed within the framework of the Caspian Federal Targeted Program (1994-95) are presented. The linear and nonlinear models of the sea level fluctuations used in scenario forecasts are discussed. Failure to take into account of any kind of the feedbacks leads to incorrect predictive estimates of the sea level fluctuations statistical characteristics.


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