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Given the significant ecological implications of coastal plumes, their dispersion and driving mechanisms have been extensively investigated, whereas existing knowledge about the limnetic ones remain unrevealed. Accordingly, this study investigated the behaviors of the Detroit (DRP) and Maumee (MRP) River sediment plumes in the semi-enclosed western basin of Lake Erie on multiple temporal scales. Results demonstrated that the two plumes' dispersions were constrained by the basin's coastlines beyond the advections induced by Ekman currents. The north and west wind forced MRP traveled downstream, while those under the south and east wind propagated upstream. The inter-annual and seasonal variability of MRP sizes are mainly impacted by its river flux, with moderate contributions of zonal wind and the Detroit River flux, resulting in significantly larger spring patches and indicating the potential interactions between the two plumes. On the other hand, DRP paced upstream under the west wind, traveled downstream under the north and east wind, and the south wind induced advection confined it at its river mouth. Its sizes varied with wind forcing and were significantly influenced by wind directions. They had limited inter-annual variations but with prominent seasonality, which featured for small summer surface patches resulting from its negative buoyancy. Overall, this study demonstrated the behavior of two dynamically distinctive limnetic plumes bounded in a semi-enclosed basin, which could further our understanding of plume dynamics in lakes and enclosed environments.

Although the significance of surface gravity waves has been consistently emphasized in previous limnetic studies, the roles of wave-current interactions in lake dynamics are not sufficiently understood due to the lack of high-resolution wave information. With a two-way coupled hydrodynamic and wave model system, this study investigated how the Lake Erie dynamics are impacted by the wave-induced surface and radiation stresses on the seasonal-mean and episodic scales. The results showed that the surface radiation stress was the same as or an order of magnitude larger than the wave-induced surface stress in the nearshore area (< 5 km offshore), while the latter prevailed in the offshore areas. By enhancing air-lake momentum and heat transfers, the wave-enhanced surface stress improved the model's skill in simulating hydrodynamics in the Central and Eastern Basins, and it was of greater importance (at least an order of magnitude larger) in modifying surges, offshore currents and thermal structures compared to those of the radiation stress. Nevertheless, the radiation stress played key roles in wave-induced nearshore currents, especially in the shallow Western Basin. Their significances reached O (0.01 to 0.1 m/s) on the seasonal and episodic scales, respectively, and could have similar importance in other shallow water environments.

Hindcast of wave dynamics in Lake Erie during 2002 to 2012 was conducted using a state-of-art finite-volume coastal ocean surface wave model (FVCOM-SWAVE). After model calibration, the surface gravity wave dynamics were examined from the aspects of wave climate and seasonality, inter-basin wave interactions, as well as its potential susceptibility to regional climate change. Compared to the Central and Eastern Basins, the Western Basin has relatively gentle wave climate. The Western Basin and the nearshore areas are most susceptible to the wave-induced bottom orbital oscillations on the seasonal mean scale, and the offshore Central Basin is sensitive to them as well during episodic events. Profound seasonality was found in both mean and extreme wave dynamics during ice-free cycles. Mean significant wave height (SWH) is highest during fall with more occurrences of extreme events (SWH > 3.1 m) and is lowest during summer, which is controlled by wind speed and direction collectively. Besides, swells generated in the Central and Eastern Basins could interact with each other under various wind directions, whereas wave generated in the Central Basin could hardly propagate into the Western Basin. In addition, the regression analysis of surrounding meteorological stations indicates increasing SWH in the Western Basin and decreasing SWH in the Eastern Basin.

Given the importance of wave–current interaction in estuarine and coastal dynamics, it is crucial to revisit impacts of surface gravity waves on three-dimensional (3D) nearshore circulation. This work investigates wave-induced circulation in three typical coastal systems including an idealized inlet and planar and natural barred beaches, by implementing the recent 3D radiation stress (RS) theory and vortex-force (VF) formalism to an unstructured-grid Finite-Volume Community Ocean Model (FVCOM). In the idealized inlet case, 3D RS generated appreciable currents near barriers and lateral boundaries while VF forced strong flows via breaking and roller-induced accelerations in front of the inlet. Both simulations indicate vertically varying wave-induced circulation that decreases markedly. In the planar beach with obliquely incident waves, both methods successfully produced surface onshore and bottom undertow, as well as the wave breaking and roller-induced longshore currents. Nevertheless, 3D RS generated unrealistic offshore currents close to the shoreline. The coupled models were validated against observations in the natural barred beach, and results indicate that the 3D RS model agrees slightly better with the observed longshore currents while 3D VF captures the vertical shear of the onshore–offshore flows reasonably. Further investigations suggest that both methods produce the wave breaking-induced surface onshore and bottom undertow successfully, yet they are located further offshore resulting from the 3D RS-induced unrealistic offshore currents. Successful implementations of the paired wave–current theories to the unstructured model would be fundamental and beneficial to the coastal ocean modeling community.

Interbasin exchange and interannual variability in Lake Erie's three basins are investigated with the help of a three-dimensional unstructured-grid-based Finite Volume Coastal Ocean Model (FVCOM). Experiments were carried out to investigate the influence of grid resolutions and different sources of wind forcing on the lake dynamics. Based on the calibrated model, we investigated the sensitivity of lake dynamics to major external forcing, and seasonal climatological circulation patterns are presented and compared with the observational data and existing model results. It was found that water exchange between the western basin (WB) and the central basin (CB) was mainly driven by hydraulic and density-driven flows, while density-driven flows dominate the interaction between the CB and the eastern basin (EB). River-induced hydraulic flows magnify the eastward water exchange and impede the westward one. Surface wind forcing shifts the pathway of hydraulic flows in the WB, determines the gyre pattern in the CB, contributes to thermal mixing, and magnifies interbasin water exchange during winter. Interannual variability is mainly driven by the differences in atmospheric forcing, and is most prominent in the CB.