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Hurricane Katrina caused extensive damage to offshore oil and gas production facilities. In this study, the state-of-the-art ocean circulation (the Princeton Ocean Model) and surface wave (Wave Watch III) models, together with high-resolution analyzed winds from NOAA/Hurricane Research Division, are used to simulate the current and wave conditions during Katrina. The model simulation shows large (>15 m) surface waves and strong (>2 m [s.sup.-1]) wind-driven and inertial currents superposed on the Loop Current and Loop Current eddy. The simulated wave fields are verified with surface buoy and satellite altimetry observations; the agreement generally is better than 0.5 m, and the correlation coefficient is above 0.95. Also, while the observed 55-ft significant wave heights on National Data Buoy Center (NDBC) buoy 42040 surpassed the previous record in the Gulf of Mexico, circumstantial evidence suggests that waves as large as 70 ft might have occurred in the storm path. Comparison with the operational analysis suggests that the current NCEP model system tends to underestimate the spatial extent of the serious wave impact.

Dispersion processes in the near-shore coastal waters 15 km south of the Hudson-Raritan estuary of New Jersey are investigated using measurements of velocity and salinity profile at two locations, one 600 m offshore in a 10.7-m-deep water and the other 1,200 m offshore in 12.8-m-deep water. Following the traditional approach, we seek to quantify dispersion coefficient K, representing the various mechanisms responsible for alongshore dispersion. The velocity and salinity measurements are decomposed into spatial and temporal averages and deviations from the averages. Using the various correlation terms, contributions to the salt flux in the alongshore direction - such as the mean advection, the residual circulation, and the oscillatory shear flow induced by wind variations - are determined. These contributions are then employed in the estimation of the horizontal (along-shore) dispersion coefficient. The time variation in the coefficient over the 30-day study period is presented, revealing a high degree of variability, with magnitudes ranging from 360 to 2,700 [m.sup.2]/s. This variability is attributed to the extremely variable wind speed and direction observed during the study period, with the freshwater discharge of the esturary also playing an important role.