1. Examples of secondary flows and lateral variability

2. U-  U S1S1 S2S2 S3S3 S4S4 U+  UU-  U S1S1 S2S2 S3S3 S4S4 Differential Advection in channel with deep middle and Shallow flanks Producing along channel salinity gradient U+  U U-  U

3. Salty Fresh Effects of Differential Advection on Flood Tide Nunes and Simpson (1985) What’s the effect on stratification? What’s the effect on the along channel momentum balance? What happens on Ebb?

4. Pressure gradient centrifugal acceleration Kalkwijk and Booij (1986) Geyer (1993) Requires Secondary flows to balance forcing

5. Secondary flows due to flow curvature From Geyer (1993)

8. Pressure gradient centrifugal acceleration Baroclinic balance arrests lateral flows Chant and Wilson (1997) Seim and Gregg (1997)

9. Current Vectors Upper layer Lower layer CTD section NY NJ NY NJ CTD section Chant and Wilson, 1997

10. Red - Surface Blue -Middle Purple- Bottom ADCP mooring Average ebb-dry period Secondary circulation Average ebb-wet period No secondary circulation Current Vectors NOAA/NOS - PORTS mooring data.

11. Wet Period 1 m/s 1m2 m 1.5 m Currents during Maximum ebb Wet Period Dry Period 1 m/s Tidal Range 1m2 m 1.5 m Red Surface Blue Bottom

12. Max Ebb vs. Tidal Range Dry Period Tidal Range Depth Tidal Range Along Channel Flow Cross Channel Flow

13. Neap Tides Tidal Range Depth Tidal Range Along Channel Flow Cross Channel Flow Max Ebb vs. Tidal Range Wet Period Spring tides

14. Wet Period - Maximum Ebb binned vs Tidal Range Stronger shear in along channel flow but weaker cross channel flows.

15. Tidal Range Stratification Moderate Strong Weak Complex Lateral Sloshing??

16. Secondary flows driven by Coriolis (Lerczak and Geyer, 2004)

17. Lerczak and Geyer (2004) model set up.

19. A z =22*10 -4 m 2 /s U f =0.25 cm/s Max(V)=10 cm/s A z =3.3*10 -4 m 2 /s U f =7.0 cm/s Max(V)= 2.6 cm/s

20. Lerczak and Geyer (2004) As stratification increases Secondary flows decrease Flood-ebb asymmetry in Secondary flows V~1/  S(z)  ranges from 1 for weakly Stratified case and approaces 100 during strongly case (represents ratio of isopycnal tilting To differential advection)

21. Tidally mean vu y +wu z Is dominated by flood Tide. Note where velocity max Is on flood (red line)

23. Figure 4 Salt section along Hudson during moderate to high flow condition during spring tide (upper panel) and neap tide (Lower panel). See figure 2 for timing of transects relative to river flow and tidal range

24. Figure 5. (upper panel) along channel currents averaged between 1.35 and 6.1 meters above the bottom water from site 4 (blue line) and its low passed filtered component (green line). (lower panel) surface (green line) and bottom (blue line) salinity during the spring of 2002. April May June

25. Exchange flow drops off more slowly than H&R predicts because H&R neglected the effect of lateral circulation that becomes more Important as mixing increases.

26. Including Coriolis produces lateral asymmetries. This would tend to transport Sediment to the right (looking seaward) and thus produce a laterally asymmetric Channel such as the Hudson.

27. Channel Cross-section at mooring array 123 4 In the afternoon we’ll look at aspects of lateral circulation based On data from the Hudson Laterally Asymmetric Channel in Hudson

31. James Neap James Spring Hudson Neap Hudson Spring Vertically Sheared Laterally Sheared Figure 3) Schematic showing movement of Hudson and James river estuary through Kevlin/Ekman number space over the spring neap cycle. Laterally sheared estuaries lie in the upper right quadrant, while vertically sheared estuaries lie in the lower left quadrant

32. U1,V1U2,V2 s1s s1b s2s Full mooring deployment (Lerczak et al. 2006) and locations of Data used in afternoon experiment