R. A. Allard    L. Hsu    K. T. Holland
Naval Research Laboratory
Stennis Space Center, MS 39529-5004
K. Miles
Sverdrup Technology, Inc.
Stennis Space Center, MS 39529-5004
J. M. Smith
Coastal and Hydraulics Laboratory
Vicksburg, MS 39180
M. Earle    C. R. Nichols
Neptune Sciences, Inc.
Reston, VA 20190

Abstract

Nearshore ocean surface wave, surf, water level, and wind data were collected at Camp Lejeune, Onslow Bay, NC from 24 Aug to 6 Sep 1997 to validate a coupled wave and surf modeling system. The field work coincided with a military exercise so the value of the data and modeling system also could be demonstrated for operational applications. Instrumentation included three Neptune Sciences  small wave buoys being developed for the Navy, five Sea-bird wave and tide gauges, four prototype expendable wave and tide gauges, a shore mounted weather station, and a shore mounted surf zone measurement video system. The waves measured during the period were representative of summer conditions with wave heights ranging from 0.2 to 1.0 m one mile offshore and 0.4 to 1.2 m just outside the surf zone. Wave periods generally ranged from 4 to 10 s. Winds measured on the beach were generally from the east and southeast with speeds typically between 2 and 9 rn/s. There were no significant storms during the period, but two cold fronts pushed through the area.

In the modeling approach, a deep water WAM model was coupled independently to the shallow water wave models, STWAVE or REF/DIFl. Outputs from both models drove the most recent version of the Navy Standard Surf Model (NSSM) which provided detailed information (e.g. breaker heights, breaker types, longshore currents) across the surf zone. Water levels (a surf model input) were calculated from the hydrodynamic model, ADCIRC. Wind input to WAM and STWAVE were obtained from the Navy Operational Regional Atmospheric prediction System. Results from the wave and surf modeling system are compared with the collected in-situ data. The video data are used to estimate wave periods, wave angles, wave speeds, longshore currents, and surf zone widths for additional comparisons.

Sponsored by Defense Modeling and Simulation Office.

Published as Abstract OS11B-17 at the American Geophys. Union Fall Meeting, San Francisco, December 1998.
Abstract