PHYSICAL MATHEMATICS SEMINAR


TITLE:		INTERNAL WAVE BREAKING ON CONCAVE
		AND CONVEX SLOPING BOUNDARIES

SPEAKER:	SONYA LEGG
		ASSOCIATE SCIENTIST, PHYSICAL OCEANOGRAPHY
		WOODS HOLE OCEANOGRAPHIC INSTITUTE



ABSTRACT: 

When internal waves reflect from a sloping boundary, the angle between the group velocity 
vector and the horizontal is preserved. As a result, for topographic slopes close to the critical 
angle, the energy density in the reflected wave may be greatly enhanced.  Laboratory and 
numerical experiments of internal wave reflection from a critical planar slope have shown that 
turbulent mixing then results. However, analytic predictions have suggested that for slopes 
which are concave about the critical point, the energy enhancement would be reduced, and less 
mixing is expected. Here this prediction is tested using numerical simulations of finite amplitude
internal wave reflection from a variety of slopes. No reduction in mixing is found for the concave 
slopes. Instead mixing is found whenever the slope angle is within a range about the critical angle 
such as to produce a reflected wave with Froude number Fr > 1, a range which is determined by
the incoming wave Froude number. 


TUESDAY, FEBRUARY 25, 2003  
2:30 pm
Building 2, Room 338

Refreshments will be served at 3:30 PM in Room 2-349

                      

Massachusetts Institute of Technology
Department of Mathematics
Cambridge, MA  02139