270 likes | 394 Views
Photo Credit : US Coast Guard, Station Yaquina Bay. Photo Credit: Hydrodynamic Processes & Ecosystems Group (HPEG), Portland State University. Modeling Updates on MCR. MCR Environment. Photo Credit : US Coast Guard, Station Yaquina Bay.
E N D
Photo Credit: US Coast Guard, Station Yaquina Bay Photo Credit: Hydrodynamic Processes & Ecosystems Group (HPEG), Portland State University Modeling Updates on MCR
MCR Environment Photo Credit: US Coast Guard, Station Yaquina Bay Photo Credit: Hydrodynamic Processes & Ecosystems Group (HPEG), Portland State University Significant wave heights () at the MCR range from 1.2 m in summer to 3 m in winter. Tidal velocities ranges from 1 m/s on flood to over 2 m/son ebb conditions. Mean monthly river discharge from CR is highly dependent on the season: reported values at the Beaver Army Terminal at Quincy varies between 3500 m3/s in September to 9600 m3/s in May.
Outline MODELING DATA ASSIMILATION • Model Setup • Validation • Mega-Transect Experiment (MGT) – 2005 • RIVET II – 2013 • Results • Wave-Current Interaction • Effect of River Plume on Waves • Conclusions • Synthetic data
1 km Model Setup • Regional Ocean Modeling System (ROMS) • Resolution: 1 km(horizontal resolution), 40 terrain-following levels • Initial & Boundary Conditions: 3 km Data Assimilating ROMS Model (Kurapov et al., 2009; Kurapov et al., 2011; Yu et al., 2012) • Model solution is provided by John Osborne.
200m Model Setup • Resolution: with 40 terrain following levels • Initial & boundary conditions & atmospheric forcing: 1 km resolution ROMS (provided by John Osborne) • Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) Modeling System(Warner et al., 2010). • Ocean Model: The Regional Ocean Modeling System (ROMS) • Wave Model: Simulating WAvesNearshore (SWAN)
USACE Mega Transect Experiment (2005) • Flow, wave and sediment measurements (Moritz et. al. 2007) 1 2 3 4 5
Forcing Conditions (Buoy 46029) River Discharge Wind Speed Wind Direction Significant Wave Height Wave Direction
Validation (2005) – Flow, Temperature and Salinity RMSE = 0.26 m/s BIAS = 0.13 m/s Skill = 0.93 RMSE = 1.10 °C BIAS = 0.13 °C Skill = 0.78 ● Obs Model RMSE = 1.16 PSU BIAS = 0.03 °C Skill = 0.93
Validation (2013) – RIVerine and Estuarine Transport (RIVET II) 7-Jun-2013 13:00 GMT Dataset provided by Rocky Geyer
Validation (2013) – RIVerine and Estuarine Transport (RIVET II) MODEL OBSERVATION 7-Jun-2013 13:00 GMT Black contour lines: totalvelocity (m/s) Surface elevation = -1.405 m (low tide)
Validation (2013) – RIVerine and Estuarine Transport (RIVET II) 7-Jun-2013 13:00 GMT Dataset provided by Rocky Geyer
Validation (2013) – RIVerine and Estuarine Transport (RIVET II) MODEL OBSERVATION 7-Jun-2013 21:00 GMT Black contour lines: totalvelocity (m/s) Surface elevation = 0.673 m (high tide)
Ocean-Wave Coupling 1-way Coupled No Coupling 2-way Coupled Ocean Model (ROMS) Ocean Model (ROMS) Ocean Model (ROMS) - currents ( - surface elevation ( - wave parameters - currents ( - surface elevation ( surface elevation ( Wave Model (SWAN) Wave Model (SWAN) Wave Model (SWAN)
Wave-Current Interaction: Effect of Currents on Waves Ebb Flood Flood Ebb Flood Ebb No coupling 2-way No coupling:only surface elevation () is passed to the wave model, no feedback from the wave model to the hydrodynamic model. Strong tidal current signature in at the mouth. The effect is more pronounced in ebb than in flood conditions.
Wave-Current Interaction: Effect of Waves on Currents Ebb Flood Flood Ebb Flood Ebb 1-way 2-way • 1-way coupled : currents and surface elevation ()are passed to the wave model, no feedback from the wave model to the hydrodynamic model.
Effect of the River Plume on Wave Height Ebb Flood Flood Ebb Flood Ebb 2-way coupled; Hs (m) 1-way coupled; Hs (m) Hs • 2-way coupled – 1-way coupled • Features of the plume reflected in the wave height ().
Effect of the River Plume on Wave Height Ebb Flood Flood Ebb Flood Ebb 2-way coupled; Hs (m) 1-way coupled; Hs (m) Hs • 2-way coupled – 1-way coupled • Features of the plume reflected in the wave height ().
Effect of the River Plume on Waves White contour lines: Salinity between 26-32 PSU Moving average of 2-way No coupling 2-way
Effect of the River Plume on Waves White contour lines: Salinity between 26-32 PSU Moving average of 2-way No coupling 2-way
Conclusions • Effect of the tidal currents on waves is substantial at the mouth: • a clear tidal signature can be seen in significant wave height (). • more pronounced in ebb than flood. • significant wave height () can increase up to 50% in ebb. • Effect of waves on tidal currents is subtle compared to vice versa. • River plume, generated by the large river discharge combined with the ebb tidal currents, causes features of the plume to be reflected in the wave height.
Member 200 Member 1 Member 2 Observations Prior Bathymetry Assimilation New Bathymetry
Work in Progress • 3D Assimilation • Running only the ocean model for 1 member only takes about 4 days to advance the model 2 days. • 2D Assimilation • Much faster, but still computationally expensive. • 2D Box Assimilation • 3D Box Assimilation
Preliminary Results Prior Iteration 1 Iteration 2 True Box, smoothing v1 Box, smoothing v2 Smoothing v1