Laboratory Study of Horizontal Mixing Process between Two River Plumes at the Sea Shelf (with an Application to the Kara Sea)

• Published in: Procedia IUTAM Vol. 8; pp. 103 - 110
• Main Authors: Elkin, D.N., Kremenetskiy, V.V., Zatsepin, A.G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2013
• Subjects: Horizontal mixing; Kara Sea; Laboratory study; Ob’ and Yenisei river plumes; Horizontal mixing; Laboratory study; Ob’ and Yenisei river plumes; Kara Sea
• ISSN: 2210-9838; 2210-9838
• DOI: 10.1016/j.piutam.2013.04.014

The area of about 40000 km2 of desalinated upper layer waters with a salinity less than 25 psu was found during cruise 54 of R/V Akademik Mstislav Keldysh in the southwestern part of the Kara Sea (September 2007). The thickness of the desalinated layer was about 10 m and it was separated from underlying marine waters with salinity more than 30 psu by strong density interface. It is likely that initial formation of this layer occurred in June when the flood of the Yenisei and Ob’ rivers inflowing into the Kara Sea at the same geographical region was maximal. The results of chemical analysis of water samples taken from this layer in different parts of the desalinated area revealed that the proportions of the content of Ob’ and Enisey waters in the samples are different. It means that the horizontal mixing process between the interacting Ob’ and Yenisei plumes in the Kara Sea is not completed even after 3 - 4 months after their formation. Laboratory experiments focusing on investigation of horizontal mixing process between two interacting fresh water plumes at the surface of saline water layer were fulfilled in the tank displaced on the rotating platform to reproduce the effects of Earth rotation. It is found that the horizontal mixing efficiency decreases with the increase of platform rotation rate. The estimate of mixing timescale based on laboratory results give the evidence that 3 - 4 months are not enough for the complete horizontal mixing of Ob’ and Yenisei river plumes.