ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

3aUW5. A study of the evolution of under-ice fresh water layer during summer melt phase in the Arctic.

Subramaniam D. Rajan

Henry Laible

Woods Hole Oceanogr. Inst., Woods Hole, MA

Walter B. Tucker, III

Cold Regions Res. and Eng. Lab., Hanover, NH

In the Arctic, the entire snow cover and a significant part of the ice melt during the summer months. The melt water, which is at about 0 (degrees)C, reaches the underside of the ice where it overlies much colder and denser saline water and forms under-ice melt ponds. It has been suggested that these under-ice melt ponds can play a significant role in heat flux through the ice. The changes in acoustic propagation in a region very close to the bottom of the ice using data collected during a multiseason cross-hole tomography experiment conducted in the Arctic are presented. Since acoustic propagation is dependent on the properties of the medium, the changes in acoustic propagation to the changes in the characteristics of the medium are related. Further an investigation is made as to whether these changes correspond to those observed by Martin and Kauffman [J. Fluid Mech. (1974)] in a laboratory experiment conducted to study the development of under-ice melt ponds. [Work supported by ONR.]