580 California St., Suite 400
San Francisco, CA, 94104
Key research themes
1. How can ship responses be used to estimate directional wave spectra and improve wave monitoring coverage?
This research area focuses on utilizing measured ship responses, such as motions and structural loads, to estimate the directional wave spectrum at the ship's location. Such methods offer potentially extensive spatio-temporal wave data coverage by transforming operating ships into moving wave buoys, complementing traditional fixed buoy, satellite, and radar measurements. The theme explores physics-based, data-driven, and hybrid approaches to improve wave estimation accuracy, robustness to operational uncertainties, and real-time applicability, thereby enriching wave monitoring networks and aiding operational performance optimization.
Key finding: The authors introduce the Wave Buoy Analogy (WBA) framework that processes wave-induced ship responses—heave, roll, pitch—to estimate directional wave spectra. A novel hybrid method combining physics-based transfer function... Read more
Key finding: Although primarily focused on ship-generated very long waves, this work empirically characterizes wave phenomena produced by large fast-displacement ships moving over bathymetric depth changes. The detailed measurements of... Read more
Key finding: This study presents SeaVision, a system that derives wind wave parameters from standard marine X-band navigation radar on ships. Validation against Spotter buoy data and WaveWatch III hindcasts in the North Atlantic confirms... Read more
Key finding: Extending the SeaVision development, this study elaborates on its deployment during multiple North Atlantic and Arctic cruises, comparing radar wave measurements to co-located Spotter buoy and WaveWatch III model outputs. The... Read more
Key finding: Utilizing the Offshore Sensing Sailbuoy equipped with a GPS-based 2 Hz motion sensor, the study demonstrates that an autonomous, wind-propelled vessel can reliably measure directional wave parameters with results closely... Read more
2. What are the dynamics and impacts of ship-generated waves in shallow and coastal waters?
This research theme investigates the characteristics, generation mechanisms, and environmental consequences of waves created by ship movements in shallow water environments such as channels, fjords, and tidal flats. It covers wave hydrodynamics near hulls, wave transformation and propagation in depth-limited domains, interaction with coastal morphology, and resulting sediment mobilization and erosion. The research spans experimental measurements, advanced numerical modeling including nonlinear and dispersive effects, and practical implications for sustainable navigation management and coastal ecosystem preservation.
Key finding: The paper develops and validates a coupled numerical modeling chain combining near-field CFD hydrodynamics with unstructured hydrodynamic models for far-field wave propagation in shallow tidal systems. Applied to the Venice... Read more
Key finding: Employing a nonlinear dispersive 2D higher-order Boussinesq-type model adapted for ship wave generation via a moving pressure disturbance, the authors simulate both near- and far-field ship-borne waves in finite-depth... Read more
Key finding: This observational and theoretical study documents the generation of very long amplitude waves (mini-tsunamis) produced by large cruiseferries in the Oslofjord when traversing sharp bathymetric depth changes at subcritical... Read more
Key finding: This study experimentally and numerically shows that waves induce unsteady inflow conditions on ship propellers causing fluctuations in thrust and torque, propeller emergence, and shaft speed variations that affect engine... Read more
3. What physical mechanisms govern the generation and statistical properties of extreme and rogue waves at sea?
This theme explores the origins and dynamics of rogue waves, focusing on nonlinear wave interactions and statistical signatures in the open ocean. It critically evaluates competing theories such as third-order quasi-resonant wave-wave modulational instabilities and second-order bound nonlinearities enhanced constructive interference. The theme includes analysis of field measurements, wave spectral modeling, and theoretical frameworks to discern which mechanisms dominate rogue wave formation in realistic multi-directional sea states and how these extremes fit within weakly nonlinear random wave statistics.
Key finding: By analyzing extensive field data from varied European locations, the study finds that rogue waves predominantly arise from constructive interference of elementary waves enhanced by second-order bound nonlinearities rather... Read more
Key finding: The paper models ship rolling induced by irregular ocean waves using nonlinear dynamic equations incorporating time-varying restoring and damping moments, accounting for coupled motions including sway and pitch. Numerical... Read more
Key finding: This work presents a practical method based on linear potential flow theory and stationary phase approximations to accurately compute both near- and far-field ship-generated wave elevations in finite depth water. The... Read more