U. Putrevu et J. Oltmanshay, INFLUENCE FUNCTIONS FOR EDGE WAVE-PROPAGATION OVER A NONPLANAR BOTTOMBATHYMETRY, Physics of fluids, 10(1), 1998, pp. 330-332
The problem of edge waves propagating over a nonplanar bottom bathymet
ry is examined. Assuming that the variation from the planar case is sm
all, we examine the problem using a perturbation expansion. This assum
ption allows an analytical estimate of how nonplanar features change t
he frequency and spatial structure of an edge wave with a given wavenu
mber. We find that these changes can be conveniently expressed in term
s of ''influence functions.'' For example, the change in frequency, si
gma(1,n), of a given edge-wave mode, n, can be expressed as sigma(1,n)
/sigma(0,n) = integral(0)(infinity)h(1)I(sigma)dx where x is the cross
-shore coordinate, h(1)(x) is the deviation from the planar topography
, sigma(0,n) is the frequency of the edge wave on a plane beach, and I
-sigma is the influence function. Similar results are also derived for
the spatial structure of the edge wave. The results show that 1) in g
eneral, the spatial structure of the edge wave is more sensitive to bo
ttom perturbations than the frequency, and 2) at a given wavenumber, t
he higher modes are more sensitive to shoreline features than the lowe
r modes. (C) 1998 American Institute of Physics.