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On thermohaline structure and circulation of the Western Large Aral Sea from 2009 to 2011: Observations and modeling

The shrinkage of the Aral Sea in the second half of the past century has significantly affected the hydrophysical regime of the lake. The objective of this paper is to report on a hydrological structure and circulation of the today’s Aral Sea based on both direct field observations and modeling results. We focus on the results of three field surveys to the Aral Sea which took place in the period from 2009 to 2011. In addition, series of numerical experiments using Princeton Ocean Model adapted to the Aral Sea was undertaken to investigate the contributions from bathymetry and water stratification in the formation of the basin scale circulation. The hydrological structure of the Aral’s western basin in autumn season exhibited a three-layered pattern with two local salinity maxima, separated by a fresher intermediate layer. According to direct observations, water circulation in the surface layer has anti-cyclonic character, while circulation in the bottom layer has cyclonic sign under the predominant northerly winds. The simulation experiments demonstrated clearly that the main cause of the anti-cyclonic circulation in the surface layer of the lake is the "asymmetric" bathymetry with broad shallow area along the eastern coast and relatively steep and deep western slope. However, strong stratification is a necessary condition for the formation of the cyclonic circulation gyre in the bottom layer

Elsevier

Author: Izhitskiy, A. S.
Zavialov, Peter O.
Roget, Elena
Huang, Hueiping
Kurbaniyazov, Abilgazy K.
Date: 2020 February 15
Abstract: The shrinkage of the Aral Sea in the second half of the past century has significantly affected the hydrophysical regime of the lake. The objective of this paper is to report on a hydrological structure and circulation of the today’s Aral Sea based on both direct field observations and modeling results. We focus on the results of three field surveys to the Aral Sea which took place in the period from 2009 to 2011. In addition, series of numerical experiments using Princeton Ocean Model adapted to the Aral Sea was undertaken to investigate the contributions from bathymetry and water stratification in the formation of the basin scale circulation. The hydrological structure of the Aral’s western basin in autumn season exhibited a three-layered pattern with two local salinity maxima, separated by a fresher intermediate layer. According to direct observations, water circulation in the surface layer has anti-cyclonic character, while circulation in the bottom layer has cyclonic sign under the predominant northerly winds. The simulation experiments demonstrated clearly that the main cause of the anti-cyclonic circulation in the surface layer of the lake is the "asymmetric" bathymetry with broad shallow area along the eastern coast and relatively steep and deep western slope. However, strong stratification is a necessary condition for the formation of the cyclonic circulation gyre in the bottom layer
Document access: http://hdl.handle.net/2072/372281
Language: eng
Publisher: Elsevier
Rights: Tots els drets reservats
Subject: Aral, Mar d’ (Uzbekistan i Kazakhstan)
Aral Sea (Uzbekistan and Kazakhstan)
Circulació oceànica
Ocean circulation
Interacció mar-atmosfera
Ocean-atmosphere interaction
Title: On thermohaline structure and circulation of the Western Large Aral Sea from 2009 to 2011: Observations and modeling
Type: info:eu-repo/semantics/article
Repository: Recercat

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