1. Internal tides Seim, Edwards, Shay, Werner Some background SAB – generation site? Shelf observations Towards a climatology?

3. Munk&Wunsch,DSR, 1998

4. Estimate of kinetic energy dissipated from M2 tide Egbert&Ray, GRL, 2003

6. Extract energy from barotropic tide where flow pushes stratified fluid over topography Vlasenko et al.,2005 Amplitude of response depends on: Height and width of obstacle Stratification strength and depth Frequency of forcing

7. Critical angle - when the angle of wave propagation matches the bottom slope can get enhanced response and wave beam type structure.

8. Tidal beam on the CA slope and associated mixing

9. Waves can be greatly modified after generation via nonlinearities, transform into Wave packets (aka solitons or solibores)

10. SC GA NC FL Wilmington Jackson- ville Savannah Charleston Our study area – SAB Big complication – Gulf Stream

12. Changes in stratification over slope can focus or defocus wave energy

13. Other fun piece – Brian Blanton’s work – annual variation in tidal amplitude – why?

14. Quoddy model runs, nested in basin scale model (Alfredo/Tom/Cisco)

15. Mean temperature structure – shoals over the slope

16. Critical angle – how best assessed? Looks like a match in places Slope angle Wave angle

17. Cross-shore velocity variance – see some maxima near areas of critical slope – generation sites?

18. SC GA NC FL Onshore side – have several years of ADCP (current meter) data – any sign on internal tide?

19. Challenge – tides dominate velocity variance and shelf so shallow that boundary layer influences structure throughout – how to isolate internal waves?

20. Describing internal structure in shallow water Goal: To remove the barotropic tide, including its associated vertical structure due to bottom friction Method: EOF analysis Isolates internal structure within energetic barotropic dynamics Done by: Catherine Edwards

21. Non-mode0 bandpassed data – lots of info…

23. Apr-Jul05 Jul-Nov05 Dec-Feb06 Feb-Jun06 Internal current variability – dominated by diurnal (near inertial) but has different structure than semi-diurnal currents (bottom- trapped?)

24. Measuring the mass field Pycnocline position varies at the semi-diurnal; current structure dominated by the diurnal Glider-measured density near R4

25. Can begin to look at cross-shore variability…from inshore (GR)

26. Across to shelfbreak (R4)

27. Towards a summary – time and cross –shore – mode 1

28. And mode2

29. In conclusion… Internal tides – exist in the SAB but not as highly NL form? Generation – likely on slope but quite variable Shelf obs – can isolate internal structure, beginning to look at variations x-shelf and with time.