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Approximate formulas and physical interpretations for horizontal acoustic modes in a shelf-slope front model
Brendan J DeCourcy1, Ying-Tsong Lin2, William L Siegmann1
1Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
Abstract:
The structure and behavior of horizontal acoustic modes for a three-dimensional idealized model of a shelf-slope front are examined analytically. The Wentzel-Kramers-Brillouin-Jeffreys (WKBJ) method is used to obtain convenient simple expressions and to provide physical insight into the structure and behavior of horizontal modes as trapped, leaky, or transition types. Validity regions for WKBJ expressions in terms of slope and frontal parameters are found, and outside the regions the asymptotic formulas for large order and large argument Hankel functions are used. These combined approximations have very good accuracy as shown by comparisons with numerical solutions for modal shapes and horizontal wavenumbers.
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