06 vorticity eqn - atmdyn.orgatmdyn.org/teaching/intro_dyn2/06_vorticity_eqn.pdf · Vorticity...

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1. Vorticity equation in z-coords 2. Physical meaning 3. Examples Vorticity equations From Wikipedia

Transcript of 06 vorticity eqn - atmdyn.orgatmdyn.org/teaching/intro_dyn2/06_vorticity_eqn.pdf · Vorticity...

  • 1. Vorticity equation in z-coords

    2. Physical meaning

    3. Examples

    Vorticity equations

    From Wikipedia

  • Governing equations

    Primitive equations in z-coords

    ut + uux + vuy + wuz − fv = −1ρ

    px

    vt + uvx + vvy + wvz + fu = −1ρ

    py

  • Governing equations

    Primitive equations in z-coords

    Vorticity equation (in z-coords)

    ut + uux + vuy + wuz − fv = −1ρ

    px

    vt + uvx + vvy + wvz + fu = −1ρ

    py

    DDt (ζ + f) = − (ζ + f) ( ∂u∂x + ∂v∂y )

    −( ∂w∂x ∂v∂z − ∂w∂y ∂u∂z )+

    1ρ2 ( ∂ρ∂x ∂p∂y − ∂ρ∂y ∂p∂x )

  • Stretching termDDt (ζ + f) = − (ζ + f) ( ∂u∂x + ∂v∂y )

    u

    v

  • Tilting term

    xy

    z

    DDt (ζ + f) = − ( ∂w∂x ∂v∂z − ∂w∂y ∂u∂z )

    u

    u

    w

    w

  • Solenoidal termDDt (ζ + f) =

    1ρ2 ( ∂ρ∂x ∂p∂y − ∂ρ∂y ∂p∂x )

    1010 hPa

    1000 hPa

    990 hPa

    ρ

  • Governing equations

    Primitive equations in z-coords

    Vorticity equation (in z-coords) (where, and )

    ut + uux + vuy + wuz − fv = −1ρ

    px

    vt + uvx + vvy + wvz + fu = −1ρ

    py

    ∇ = ∇2 ⃗u = iu + jvDDt (ζ + f) = − (ζ + f)∇ ⋅ ⃗u − ∇w ×

    ∂ ⃗u∂z

    +1ρ2

    ∇ρ × ∇p

    StretchingTerm

    TiltingTerm

    SolenoidalTerm

  • Example (stretching)

    Youtube NSF Fluid Mechanics Series (9.Vorticity 2/2 11분30초)

  • Example (tilting)

    From Holton, originally from Klemp (1987)

    Youtube: Vorticity 4K (Mike Olbinski) (Wind shear 0:59, Rotation 4:21, Tornado: 5:07)

  • Example (tilting)

    Youtube NSF Fluid Mechanics Series 
(9.Vorticity 2/2 14:15)

    곡류천의 예
(https://educalingo.com/)

  • Example (solenoid)

    From Essentials of Meteorology (Ahrens)

  • Example (solenoid)

    From Holton