Thermohaline strucutre and circulation of the Western Large Aral Sea in the beginning of XXI century A. S. Izhitskiy 1 , P.O. Zavialov 1 and E. Roget 2 Girona, 27 of June 2014 1 Shirshov Institute of Oceanology RAS, Moscow, Russia 2 University of Girona, Catalonia, Spain
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Thermohalinestrucutreand circulation of the Western Large ... · Water circulation –“natural” conditions the peculiar feature of the water circulation in the Aral Sea in its
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Thermohaline strucutre and circulation of
the Western Large Aral Sea in the beginning
of XXI century
A. S. Izhitskiy1, P.O. Zavialov1 and E. Roget2
Girona, 27 of June 2014
1 Shirshov Institute of Oceanology RAS, Moscow, Russia2 University of Girona, Catalonia, Spain
Motivation
The fourth largest lake on Earth in 1960, the Central Asia’s Aral Sea has lost over 80% of its area and over 90% of its
volume because of severe desiccation, associated mainly with unsustainable diversions of water for irrigation from the
tributary rivers.
The changes in physical and geographical conditions occurred in past 50 years have led to considerable rebuilding of the
entire hydrological structure of the sea.
In comparison with pre-desiccation state the overall level drop was about 27 m.
the significance of the ongoing changes of the Aral Sea is not limited to the applied, regional aspects. The lake can be
thought of as a “natural laboratory”, where the evolution of a large inland water body under anthropogenic intervention
through diversions of the river runoff can be investigated.
The shrinkage resulted in profound changes of the lake’s ecosystem and desertification of the surrounding areas.
main objective
investigation of the hydrological regime and
circulation of the today’s Aral Sea
methods
direct field observations
numerical modelling
Thermohaline structure – “natural” conditions
Salinity (ppt) distribution in summer, typical for the predesiccation
Aral Sea. Longitudinal vertical section through the western deep
basin [Zavialov , 2009].
Surface salinity (ppt) distribution in summer,
typical for the predesiccation Aral Sea
[Zavialov, 2009].
• the slim spatial and vertical variability of salinity, except the
estuaries regions
• the relatively small vertical density stratification
• the vertical stratification was governed mainly by
temperature
• thermal and haline mixing of the water column, full
ventilation through the year
Water circulation – “natural” conditions
the peculiar feature of the water circulation in the Aral Sea in its predesiccation