FORECASTING THE WAVE-CURRENT INTERACTIONS AT THE MOUTH OF THE COLUMBIA RIVER, OR, USA

Sarah Kassem, H. Tuba Ozkan-Haller

Abstract


An operational wave forecast of the area near the mouth of the Columbia River is presented. This region is known for its large waves and strong tidal currents. The forecast is forced with full directional spectra obtained from a refined WaveWatchIII forecast of the Pacific Northwest, and tidal current inputs are obtained from an estuarine circulation forecast of the Columbia River. The forecast has been operational since August 2011 providing short-term predictive wave information at the mouth of the Columbia River. Results from a 6-month period are promising, with a normalized root-mean-squared error (NRMSE) of 16% at the location of an inshore buoy, which is located outside the zone of tidal influence in 25 m water depth. Near the river mouth and in the channel, wave heights are heavily dominated by the tidal currents which significantly increase wave heights on ebb tides. Hindcast results shows that the model is able to predict the general effect of the tidal currents with a NRMSE of 30% in wave heights at the river mouth. Despite some of the model limitations, it still provides valuable information to navigators and bar pilots since it includes the effects of the tidal currents.

Keywords


wave-curren interactions; Columbia River; Forecasting; SWAN

References


Allan, J.C., and P.D. Komar. 2002. Extreme storms on the Pacific Northwest coast during the 1997-98 el niño and 1998-99 la niña, Journal of Coastal Research, 18 (1), 175-193.

Battjes, J.A., and J.P.F.M Janssen. 1978. Energy loss and set-up due to breaking of random waves, Proceedings of the 16th International Conference on Coastal Engineering, ASCE, 569-587.

Booij, N., Ris, R.C., and L.H. Holthuijsen. 1999. A third-generation wave model for coastal regions 1. Model description and validation. Journal of Geophysical Research, 104 (C4), 7649-7666.http://dx.doi.org/10.1029/98JC02622

Elias, E., Gelfenbaum, G., and A. Van der Westhuysen. 2012. Validation of a coupled wave-flow model in a high-energy setting: The mouth of the Columbia River, Journal of Geophysical Research, 117, 21 pp.

García-Medina, G., Özkan-Haller, H.T., Ruggiero, P., and J. Oskamp. 2012. A nearshore wave forecasting system for the US Pacific Northwest, Weather and Forecasting, (in review).

González, F.I. 1984. A case study of wave-current-bathymetry interactions at the Columbia River entrance, Journal of Physical Oceanography, 14 (6), 1065-1078.2.0.CO;2">http://dx.doi.org/10.1175/1520-0485(1984)014<1065:ACSOWI>2.0.CO;2

Komen, G.J., Hasselmann, S., and K. Hasselmann. 1984. On the existence of a fully developed windsea spectrum, Journal of Physical Oceanography, 14, 1271-1285.2.0.CO;2">http://dx.doi.org/10.1175/1520-0485(1984)014<1271:OTEOAF>2.0.CO;2

Moritz, H.R., Gelfenbaum, G.R., and P. Ruggiero. 2005. Morphological implications of oceanographic measurements acquired along a mega-transect at the mouth of the Columbia River, USA. AGU Fall Meeting, Abstract OS23A-1534.

Moritz, H.R., Gelfenbaum, G.R., Kaminsky, G.M., Ruggiero, P., Oltman-Shay, J., and J.D. Mckillip. 2007. Implementing regional sediment management to sustain navigation at an energetic tidal inlet, Coastal Sediments 2007, ASCE.

Ruggiero, P., Kaminsky, G.M., Gelfenbaum, G., and B. Voigt. 2005. Seasonal to interannual morphodynamics along a high-energy dissipative littoral cell, Journal of Coastal Research, 21 (3), 553-578.http://dx.doi.org/10.2112/03-0029.1

Zhang, Y., Baptista, A.M., and E.P. Myers III. 2004. A cross-scale model for 3D baroclinic circulation in estuary-plume-shelf systems: I. Formulation and skill assessment, Continental Shelf Research, 24 (18), 2187-2214.http://dx.doi.org/10.1016/j.csr.2004.07.021


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