1. Freshwater input
Salty water inflow
(near the bottom)
Along the Estuary: Pressure Gradient balanced by Friction (Pritchard, 1956)

2. Pressure gradient vs. vertical mixing

4. C
Burchard & Hetland (2010, JPO, 40, 1243)

5. Jay (2010, in Contemporary Issues in Estuarine Physics, Chap. 4)
Burchard & Hetland (2010, JPO, 40, 1243)

8. looking into the bay
Further seaward: surface outflow; bottom inflow

9. Outflow over shoals; inflow in channels
Looking into the bay IN
OUT
Outflow over shoals; inflow in channels
WHY THE DIFFERENCE?
E = Az / [ f H 2 ]

10. Examples in the lower Chesapeake Bay with different E.
Which has larger
E = Az / [ f H 2 ] ?
Larger E
Smaller E

11. Along-basin: Across-basin:
Pressure Gradient Pressure Gradient
+ Friction Friction
+ Coriolis Coriolis
Friction/Coriolis
E = A z / (f H 2)

12. Ekman # -- proxy for dynamical DEPTH
Friction/Coriolis
E = A z / (f H 2)
frictional
influence z z y y
Small E
Deep Basin
Large E
Shallow Basin

13. Along-basin: Across-basin:
Pressure Gradient Pressure Gradient
+ Friction Friction
+ Coriolis Coriolis
Friction/Coriolis
E = A z / (f H 2)

14. w = u + iv z – vertical distance from the surface
H – total water column depth
D – density gradient
N – sea level slope
α = (1 + i )/DE, where DE = [2Az / f ] ½
w = u + iv

15. Friction/Coriolis E = A z / (f H 2) Friction increases
Coriolis increases
deep
depth
distance
It matters how Deep!
shallow
(red is inflow; white is outflow)
(contours are normalized with the
maximum flow)
Valle-Levinson et al, 2003, JPO

16. Ri
out B in

17. Width matters! low E med E high E Ke = B/R; E = Az / (f H2) (wide)
(narrow)
Width matters!
low E
deep
med E
Ke = B/R; E = Az / (f H2)
high E
shallow
(looking into the estuary; orange is inflow; white is outflow)
Valle-Levinson, 2008, JGR

18. low E med E high E Adriatic & Med Rías Gibraltar Estuaries Ke = B/R
(wide)
(narrow)
low E
deep
Adriatic &
Med
Rías
Gibraltar
med E
Estuaries
high E
shallow
Ke = B/R
E = Az / (f H2)
Valle-Levinson, 2008, JGR