102
Air Pollution and Turbulence: Modeling and Applications
Frequently, this fraction is taken to be constant and equal to 0.2 (e.g., Stull 1976).
This assumption was the basis of a parameterization used in several models. In these
parameterizations, the ED in the CBL, K topo , is set to satisfy that ratio between the
fl uxes, that is,
Δ
= −
θ
′ ′ Δθ
topo
0.2(
)
.
v s
v
z
K
w
(4.66)
Such approximation was implemented in the ECMWF model (Beljaars and Betts
1992).
Δθ v
(w΄θ΄ v ) z i
(w΄θ΄ v ) s
w΄θ΄ v (Wm
–2 )
0
θ v (K)
z i
z (m)
Y
(a)
(w΄θ΄ v ) s
w΄θ΄ v (Wm
–2 )
0
θ v (K)
(w΄θ΄ v ) z i
δz
Y
h
z i
z (m)
Δθ v
(b)
FIGURE 4.16 Vertical profi les of φ
–
v and
θ
′ ′
(
)
v s
w
in jump models: (a) zeroth-order and
(b) fi rst-order. γ = ∂φ
–
v /∂z in the inversion region, z i is the inversion height, Δφ
–
vi is the intensity
of the inversion, and δz is the inversion thickness.
© 2010 by Taylor and Francis Group, LLC
Air Pollution and Turbulence: Modeling and Applications
Frequently, this fraction is taken to be constant and equal to 0.2 (e.g., Stull 1976).
This assumption was the basis of a parameterization used in several models. In these
parameterizations, the ED in the CBL, K topo , is set to satisfy that ratio between the
fl uxes, that is,
Δ
= −
θ
′ ′ Δθ
topo
0.2(
)
.
v s
v
z
K
w
(4.66)
Such approximation was implemented in the ECMWF model (Beljaars and Betts
1992).
Δθ v
(w΄θ΄ v ) z i
(w΄θ΄ v ) s
w΄θ΄ v (Wm
–2 )
0
θ v (K)
z i
z (m)
Y
(a)
(w΄θ΄ v ) s
w΄θ΄ v (Wm
–2 )
0
θ v (K)
(w΄θ΄ v ) z i
δz
Y
h
z i
z (m)
Δθ v
(b)
FIGURE 4.16 Vertical profi les of φ
–
v and
θ
′ ′
(
)
v s
w
in jump models: (a) zeroth-order and
(b) fi rst-order. γ = ∂φ
–
v /∂z in the inversion region, z i is the inversion height, Δφ
–
vi is the intensity
of the inversion, and δz is the inversion thickness.
© 2010 by Taylor and Francis Group, LLC