Assessment of a Fully Coupled Circulation-Wave Model for the Mouth of the Columbia River

Tuesday, 16 December 2014
Cigdem Akan1, Saeed Moghimi1, H Tuba Ozkan-Haller2, Alexander L Kurapov3, John J Osborne3, Ruth Branch4, C Chris Chickadel5, Gordon Farquharson6, W Rockwell Geyer7, Merrick C Haller1, Guillermo Díaz Méndez1 and James M Thomson4, (1)Oregon State University, Corvallis, OR, United States, (2)Oregon St Univ, Corvallis, OR, United States, (3)COAS/Oregon State Univ, Corvallis, OR, United States, (4)Applied Physics Lab (UW), Seattle, WA, United States, (5)University of Washington Seattle Campus, Seattle, WA, United States, (6)University of Washington, Seattle, WA, United States, (7)WHOI, Woods Hole, MA, United States
Numerical simulations were performed for the Mouth of the Columbia River (MCR) using a 3D ocean circulation model (ROMS) two-way coupled to a phase-averaged wave propagation model (SWAN) within the framework of a collaborative project called DARLA (Data Assimilation and Remote Sensing for Littoral Applications) funded by the Office of Naval Research (ONR). Model results were compared against an extensive data set obtained during the Riverine and Estuarine Transport II (RIVET II) experiment done in May-June, 2013. Data sources used in the aforementioned multi-institution effort experiment include CTD casts, SAR, RADAR, LIDAR and SWIFT measurements and thus present a unique chance to qualitatively and quantitatively analyze the model output. In order to assess the model performance quantitatively, root mean square (RMS) error, bias, model skill and scatter index were used. In general, the model is able reproduce the temporal and spatial behavior of the momentum and scalar transport (temperature and salinity). Also, modeled wave parameters are in good agreement with the LIDAR and RADAR observations. Finally, the effect of the river plume on the waves and vice versa is discussed and advantages and disadvantages of nesting from a realistic outer model are reported.