Presentation is loading. Please wait.

Presentation is loading. Please wait.

Estuarine circulation

Similar presentations


Presentation on theme: "Estuarine circulation"— Presentation transcript:

1 Estuarine circulation
Announcements Research groups Cruise dates Added another project – WC respiration Thursday: Thompson paper discussion

2 Equations of motion, momentum (Navier-Stokes equations)
Momentum equations: Force/vol Pressure Coriolis Gravity Friction Dρu/Dt = ∂p/∂x + ρ2Ωvsin(φ) Kx(∂2ρu/∂x2+∂2ρu/∂y2+∂2ρu/∂z2 ) Dρv/Dt = ∂p/∂y - ρ2Ωusin(φ) Ky(∂2ρv/∂x2+∂2ρv/∂y2+∂2ρv/∂z2 ) Dρw/Ddt = ∂p/∂z ρg Kz(∂2ρw/∂x2+∂2ρw/∂y2+∂2ρw/∂z2 ) where Dρu/Dt = ∂ρu/∂t + u∂ρu/∂x + v∂ρu/∂y + w∂ρu/∂z Dρv/Dt = ∂ρv/∂t + u∂ρv/∂x + v∂ρv/∂y + w∂ρv/∂z Dρw/Dt = ∂ρw/∂t + u∂ρw/∂x + v∂ρw/∂y + w∂ρw/∂z (non-linear terms) Equation of Continuity: ∂u/∂x + ∂v/∂y + ∂w/∂z = 0 Number of unknowns: 7 (u, v, w, p, Kx, Ky, Kz) (velocities, pressure, eddy viscosities) Number of equations: 4 Turbulence closure: 3 equations to relate Kx, Ky, Kz to u, v, and w (This problem remains unsolved in a general way, but many approximate solutions exist)

3 Pressure gradient terms
Barotropic fields Isobars and isopyncnals parallel Baroclinic fields Isobars and isopyncnals inclined Sea surface Isobar Isopycnal Level surface

4 Estuary density gradients

5 Estuary density gradients
Salinity distributions in Puget Sound South Sound Admiralty Inlet

6 Ebbesmeyer et al.

7 Estuarine circulation with sills
Thompson 1994

8 Residual circulation Mean circulation after subtracting the oscillating tidal circulation Important for calculating mean transport in and out of Puget Sound

9 PS mean circulation Ebbesmeyer et al.

10 Instantaneous circulation
Several numerical models of Puget Sound circulation: Department of Ecology – South Puget Sound PNNL Salish Sea Model UW MoSSea King County model USGS model

11 Equations of motion, momentum (Navier-Stokes equations)
Momentum equations: Force/vol Pressure Coriolis Gravity Friction Dρu/Dt = ∂p/∂x + ρ2Ωvsin(φ) Kx(∂2ρu/∂x2+∂2ρu/∂y2+∂2ρu/∂z2 ) Dρv/Dt = ∂p/∂y - ρ2Ωusin(φ) Ky(∂2ρv/∂x2+∂2ρv/∂y2+∂2ρv/∂z2 ) Dρw/Ddt = ∂p/∂z ρg Kz(∂2ρw/∂x2+∂2ρw/∂y2+∂2ρw/∂z2 ) where Dρu/Dt = ∂ρu/∂t + u∂ρu/∂x + v∂ρu/∂y + w∂ρu/∂z Dρv/Dt = ∂ρv/∂t + u∂ρv/∂x + v∂ρv/∂y + w∂ρv/∂z Dρw/Dt = ∂ρw/∂t + u∂ρw/∂x + v∂ρw/∂y + w∂ρw/∂z (non-linear terms) Equation of Continuity: ∂u/∂x + ∂v/∂y + ∂w/∂z = 0

12 Modeled currents in southern PS
DOE SPS model

13 Equations of motion Momentum equations:
Force/vol Pressure Coriolis Gravity Friction ρDu/Dt = ∂p/∂x + ρ2Ωvsin(φ) ρKx(∂2u/∂x2+∂2u/∂y2+∂2u/∂z2 ) ρDv/Dt = ∂p/∂y - ρ2Ωusin(φ) ρKy(∂2v/∂x2+∂2v/∂y2+∂2v/∂z2 ) ρDw/Ddt = - ∂p/∂z ρg ρKz(∂2w/∂x2+∂2w/∂y2+∂2w/∂z2 ) where Du/Dt = ∂u/∂t + u∂u/∂x + v∂u/∂y + w∂u/∂z Dv/Dt = ∂v/∂t + u∂v/∂x + v∂v/∂y + w∂v/∂z Dw/Dt = ∂w/∂t + u∂w/∂x + v∂w/∂y + w∂w/∂z (non-linear terms) Equation of Continuity: ∂u/∂x + ∂v/∂y + ∂w/∂z = 0

14 Scaling momentum equation
Importance of individual terms Re = Reynolds number = L u / n Inertial forces / viscous forces (100m) (0.1 m/s) / 10-6 m2/s) = 107 R0 = Rossby number = u / (f L), f = 2ωsin(φ) Non-linear terms / coriolis term (1 m/s) / ((10-4 s-1)(104 m)) = 1 Rossby radius of deformation ~ u/f = 10 km Ez = Ekman number = Kz/(f H2) Friction term / coriolis term (10-4 m2/s) / ((10-4 s-1)(100m)2) = 10-4 Friction only important along the boundaries of Puget Sound (sea surface, bottom boundary layer)

15 SJF cross section Northern shore Southern shore Out In


Download ppt "Estuarine circulation"

Similar presentations


Ads by Google