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1. Direct measurements reveal instabilities and turbulence within large amplitude internal solitary waves beneath the ocean

   https://doi.org/10.1038/s43247-020-00083-6  

   Chang, Ming-Huei; Cheng, Yu-Hsin; Yang, Yiing Jang; Jan, Sen; Ramp, Steven R.; Reeder, D. Benjamin; Hsieh, Wan-Ting; Ko, Dong S.; Davis, Kristen A.; Shao, Huan-Jie; et al (December 2021, Communications Earth & Environment)

   null (Ed.)

   Abstract Internal solitary waves are ubiquitous in coastal regions and marginal seas of the world’s oceans. As the waves shoal shoreward, they lose the energy obtained from ocean tides through globally significant turbulent mixing and dissipation and consequently pump nutrient-rich water to nourish coastal ecosystem. Here we present fine-scale, direct measurements of shoaling internal solitary waves in the South China Sea, which allow for an examination of the physical processes triggering the intensive turbulent mixing in their interior. These are convective breaking in the wave core and the collapse of Kelvin–Helmholtz billows in the wave rear and lower periphery of the core, often occurring simultaneously. The former takes place when the particle velocity exceeds the wave’s propagating velocity. The latter is caused by the instability induced by the strong velocity shear overcoming the stratification. The instabilities generate turbulence levels four orders of magnitude larger than that in the open ocean. 

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2. Calving as a Source of Acute and Persistent Kinetic Energy to Enhance Submarine Melting of Tidewater Glaciers

   https://doi.org/10.1029/2025GL117900  

   Shaya, M F; Nash, J D; Pettit, E C; Amundson, J M; Jackson, R H; Sutherland, D A; Winters, D (October 2025, Geophysical Research Letters)

   Abstract Calving icebergs at tidewater glaciers release large amounts of potential energy. This energy—in principle—could be a source for submarine melting, which scales with near‐terminus water temperature and velocity. Because near‐terminus currents are challenging to observe or predict, submarine melt remains a key uncertainty in projecting tidewater glacier retreat and sea level rise. Here, we study one submarine calving event at Xeitl Sít’ (LeConte Glacier), Alaska, to explore the effect of calving on ice melt, using a suite of autonomously deployed instruments beneath, around, and downstream of the calving iceberg. Our measurements captured flows exceeding 5 m/s and demonstrate how potential energy converts to kinetic energy . While most energy decays quickly (through turbulence, mixing, and radiated waves), near‐terminus remains elevated, nearly doubling predicted melt rates for hours after the event. Calving‐induced currents could thus be an important overlooked energy source for submarine melt and glacier retreat. 

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3. Subglacial brine flow and wind-induced internal waves in Lake Bonney, Antarctica

   https://doi.org/10.1017/S0954102020000036  

   Lawrence, Jade P.; Doran, Peter T.; Winslow, Luke A.; Priscu, John C. (June 2020, Antarctic Science)

   Abstract Brine beneath Taylor Glacier has been proposed to enter the proglacial west lobe of Lake Bonney (WLB) as well as from Blood Falls, a surface discharge point at the Taylor Glacier terminus. The brine strongly influences the geochemistry of the water column of WLB. Year-round measurements from this study are the first to definitively identify brine intrusions from a subglacial entry point into WLB. Furthermore, we excluded input from Blood Falls by focusing on winter dynamics when the absence of an open water moat prevents surface brine entry. Due to the extremely high salinities below the chemocline in WLB, density stratification is dominated by salinity, and temperature can be used as a passive tracer. Cold brine intrusions enter WLB at the glacier face and intrude into the water column at the depth of neutral buoyancy, where they can be identified by anomalously cold temperatures at that depth. High-resolution measurements also reveal under-ice internal waves associated with katabatic wind events, a novel finding that challenges long-held assumptions about the stability of the WLB water column. 

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4. Breaking Internal Waves on Sloping Topography: Connecting Parcel Displacements to Overturn Size, Interior-Boundary Exchanges, and Mixing

   https://doi.org/10.1175/JPO-D-24-0052.1  

   Whitley, Victoria; Wenegrat, Jacob (June 2025, Journal of Physical Oceanography)

   Internal waves impinging on sloping topography can generate mixing through the formation of near-bottom bores and overturns in what has been called the “internal swash” zone. Here, we investigate the mixing generated during these breaking events and the subsequent ventilation of the bottom boundary layer across a realistic nondimensional parameter space for the ocean using three-dimensional large-eddy simulations. Waves overturn and break at two points during a wave period: when the downslope velocity is strongest and during the rapid onset of a dense, upslope bore. From the first overturning bore to the expulsion of fluid into the interior, there is a strong dependence on the effective wave height, a length scale defined by the ratio of wave velocity over the background buoyancy frequency, an upper bound on the vertical parcel displacement an internal wave can cause. While a similar energetically motivated vertical length scale is often seen in the context of lee-wave generation over topography, the results discussed here suggest this readily measurable parameter can be used to estimate the size of near-boundary overturns, the strength of the ensuing turbulent mixing, and the vertical scale of the along-isopycnal intrusions of fluid ejected from the boundary layer. Examining a volume budget of the near-boundary region highlights spatial and temporal variability that must be considered when determining the water mass transformation during this process. 

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5. Data and scripts from: A robust numerical method for the generation and propagation of periodic finite-amplitude internal waves in natural waters using high-accuracy simulations

   https://doi.org/10.7298/5vkw-0303  

   Lloret, Pierre; Diamessis, Peter; Stastna, Marek; Thomsen, Greg N (November 2024, Cornell University Library)

   These files contain data supporting all results reported in Lloret et al. "A robust numerical method for the generation and propagation of periodic finite-amplitude internal waves in natural waters using high-accuracy simulations". In Lloret et al. we found: The design and implementation of boundary conditions for the robust generation and simulation of periodic finite-amplitude internal waves is examined in a quasi two-layer continuous stratification using a spectralelement-method-based incompressible flow solver. The commonly used Eulerian approach develops spurious, and potentially catastrophic small-scale numerical features near the wave-generating boundary in a non-linear stratification when the parameter A/(δc) is sufficiently larger than unity; A and δ are measures of the maximum wave-induced vertical velocity and pycnocline thickness, respectively, and c is the linear wave propagation speed. To this end, an Euler–Lagrange approach is developed and implemented to generate robust high-amplitude periodic deep-water internal waves. Central to this approach is to take into account the wave- induced (isopycnal) displacement of the pycnocline in both the vertical and (effectively) upstream directions. With amplitudes not restricted by the limits of linear theory, the Euler–Lagrange-generated waves maintain their structural integrity as they propagate away from the source. The advantages of the high-accuracy numerical method, whose minimal numerical dissipation cannot damp the above near-source spurious numerical features of the purely Eulerian case, can still be preserved and leveraged further along the wave propagation path through the robust reproduction of the non-linear adjustments of the waveform. The near- and far-source robustness of the optimized Euler–Lagrange approach is demonstrated for finite-amplitude waves in a sharp quasi two- layer continuous stratification representative of seasonally stratified lakes. The findings of this study provide an enabling framework for two-dimensional simulations of internal swash zones driven by well-developed non- linear internal waves and, ultimately, the accompanying turbulence-resolving three-dimensional simulations. Please cite as: Lloret, P., Diamessis, P., Stastna, M., & Thomsen, G. N. (2024). Data and scripts from: A robust numerical method for the generation and propagation of periodic finite-amplitude internal waves in natural waters using high-accuracy simulations [Data set]. Cornell University eCommons Repository. https://doi.org/10.7298/5VKW-0303 

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