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

2pUW16. Application of the mode vector parabolic equation to the 3-dimensional wedge problem.

Ahmad T. Abawi

W. A. Kuperman

Marine Phys. Lab., Scripps Inst. of Oceanogr., Univ. of California, San Diego, La Jolla, CA 92093-0238

The MVPE [Abawi et al., this session] is applied to the problem of propagation of waves in a 3-dimensional coastal wedge and the results are compared with those when horizontal coupling is neglected and with the results obtained from conventional 3-dimensional methods. The components of the solution vector are the amplitudes of the vertical modes which are coupled in both range and azimuth. The coupling matrices for both range and azimuth are precomputed by the method summarized in [McDonald et al., 2357 (1994)]. In the absence of mode coupling, the solution reduces to the solution of the adiabatic mode parabolic equation [M. D. Collins, 2269 (1993)]. The system of equations are numerically solved by the Crank--Nicholson finite difference method. For a single vertical mode, this system of equations closely resembles a system of discretized parabolic equation in range and azimuth. For multiple modes, the matrices involved are band diagonal with the coupling matrices appearing in their diagonal. The size of these matrices are thus equal to the number of points in azimuth times the number of vertical modes. When the physics of the problem is contained in a subset of coupled modes, this method offers additional advantages in numerical computation over the conventional 3-dimensional methods.