Kuperman and Ingenito [49] obtained the following interface condition for an interface with RMS roughness :

where the elements of **A** are given by:

with,

and,

The subscripts 1 and 2 denote properties in the upper and lower media, respectively. For a free surface the appropriate result is obtained by letting and go to zero. Note that this formula also breaks down in a catastrophic fashion if is too large.

Tue Oct 28 13:27:38 PST 1997