This paper presents a case study on the wave-current interaction near
the local curvature of a Gulf Stream meander. The wave data were obtai
ned from in situ measurements by a pitch-roll discus buoy during the S
urface Wave Dynamics Experiment (SWADE) conducted off Wallops Island,
Virginia, from October 1990 to March 1991. Owing to the advection of t
he Gulf Stream by the semidiurnal tide, the discus buoy was alternatel
y located outside and inside the Gulf Stream. The directional wave mea
surements from the buoy show the changes in wave direction, wave energ
y, and directional spreading when waves encountered the current in the
Gulf Stream meanders. A wave refraction model, using the ray-tracing
method with an estimated Gulf Stream velocity field and meandering con
dition, was used to simulate wave refraction patterns and to estimate
wave parameters at relative locations corresponding to buoy measuremen
ts. The numerical simulation shows that a focusing zone of wave rays w
as formed near the boundary and behind the crest of a simulated Gulf S
tream meander. The focusing of wave rays causes changes in wave direct
ion, increases in wave energy, and decreases in wave directional sprea
ding, which are in good agreement with the results from the buoy measu
rements.