130 likes | 245 Views
Internal Tides, Mixing and the Bottom Boundary Layer. James Girton and Eric Kunze APL/UW and Univ. Victoria. Monterey Canyon Internal Tides. From Kunze, Rosenfeld, Carter, and Gregg (JPO 2002). Beams and Flux Divergence. From Kunze, Rosenfeld, Carter, and Gregg (JPO 2002).
E N D
Internal Tides, Mixing and the Bottom Boundary Layer James Girton and Eric Kunze APL/UW and Univ. Victoria
Monterey Canyon Internal Tides From Kunze, Rosenfeld, Carter, and Gregg (JPO 2002)
Beams and Flux Divergence From Kunze, Rosenfeld, Carter, and Gregg (JPO 2002)
Critical Reflection From Nash, Kunze, Toole, and Schmitt (JPO 2004)
Bottom Boundary Mixing Successive mixing events and subsequent collapse lead to gradual dispersal of boundary layer fluid away from margin Internal wave breaking mixes stratified fluid near boundary Shadowgraph image: subcritical internal wave breaking against a sloping boundary. Fluorescein-dyed boundary layer fluid spreading into the interior. From McPhee-Shaw and Kunze (JGR 2002)
BBL Bores in the Canyon From Rosenfeld et al (‘Aha 1999)
8 occupations of 9 stations (72 XCPs) over 12.4 hours, followed by microstructure time-series. • 5 km 5 km box, resolves M2 and M4 harmonic. • Additional 1/2-hourly XCP+microstructure time-series for 12.4 hours at one spot to resolve high-frequency variability • Max XCP depth = 2000 m; profiles to 1 m above bottom Survey Box
Processes/Observables • Energy flux divergence vs. local dissipation • Near-critical reflection (bispectra) • Bottom boundary-layer stress and bores • Stratification flux from boundary • Nonlinearity of semidiurnal tide (M4) • Impact of wave-field coherence on mixing parameterizations
TPXO Surface Tides From Klymak and Pinkel proposal
Now Where? • Slope North of Bay • Corrugated Topography • Submarine Fan • Broad Ridge South of Bay
Timing/Location Criteria • 3 cycles of the semidiurnal tide (close to spring) • Less than 2000 m water depth • Probably site survey nearFLIP • Strong internal tides and 2-D geometry preferred