1. Lake Iseo Field Experiment
Leticia Chamelete de Vilhena

2. Energy transfer
Basin-scale internal waves decay at a higher rate than can be accounted for simply by internal dissipation
Other mechanisms must act to transfer energy from these basin-scale waves to turbulent scales

3. High frequency waves Ubiquitous to lakes and oceans
Exist in narrow but discrete frequency bands approaching the buoyancy frequency, N
Important in the cascade of energy to turbulent scales
Enhance dissipation and mixing, bringing significant implications to mass fluxes and bioproductivity
Shear instabilities
Nonlinear steepening of basin-scale internal waves
Internal hydraulic jumps
Excitation by intrusions and gravity currents
Flow interaction with boundaries

4. Nonlinear waves
2 groups: waves described by linear stability models, and waves described by nonlinear models
Steepening timescale (Horn et al. 2001) determines when nonlinear effects are important
Moderate forcing
Layer depth ratio
This spectrum is composed of progressive waves, containing both weakly and strongly nonlinear waves, the former consisting of a sinusoidal profile with frequencies near 10-4 Hz, while the latter can be described by a hyperbolic-secant-squared profile with frequencies near 10-3 Hz

5. Objectives
Role of nonlinear waves on the transfer of energy and resulting mixing is still incomplete
The breaking of high frequency waves and the resulting mixing may be a significant way of maintaining the lake’s productivity and the health of the ecosystem
especially when the effects of topography and complex stratification found in the field are considered
Esp. in a strongly stratified water body such as Lake Iseo,

6. Objectives
Document the generation of nonlinear waves in the Southern embayment of Lake Iseo
Document breaking of high frequency waves and resulting mixing
Calculate the energy flux going into high frequency waves and the dissipation in the water column

7. Methods F-probe + Microstructure data Non-hydrostatic ELCOM
Most numerical models employed to study the hydrodynamics of lakes make the hydrostatic approximation. While these models have been used to satisfactorily simulate most flows, by neglecting vertical accelerations they are unable to capture the evolution and propagation of solitons and therefore the transfer of energy from the basin-scale seiche to these shorter waves. Therefore, to correctly simulate this degeneration process with the Navier–Stokes equations, a model must reproduce both non-linearities and non-hydrostatic pressure.