Geoscience Reference
In-Depth Information
10.11 Discuss the behavior of
R
f
and
Ri
in the asymptotic stable state. How could
this state determine the depth of the nocturnal ABL?
10.12 Explain the role of the second-moment budgets in turbulent flow calculation.
10.13 Derive an expression for the eddy diffusivity for momentum in the surface
layer. Discuss its asymptotic behavior.
10.14 Identify and discuss the rate of buoyant production of vertical temperature
flux. What is its role in unstable conditions? In stable conditions?
10.15 Explain why large-eddy simulation generally does not perform well in the
atmospheric surface layer. (Hint: consider the behavior of the length scale
of the vertical velocity field near the surface.)
10.16 In large-eddy simulation of the atmospheric boundary layer the surface fluxes
are typically determined from the resolved (calculated) fields through the
standard surface-exchange coefficients. Is this justifiable? Discuss.
10.17 Use dimensional analysis t
o
determine the averaging time
T
required to
determine the time average
u
T
u(t)
with
ensemble mean
U
,variance
u
2
, and integral scale
τ
. Can you obtain the
answer,
Eq. (2.36)
? Explain.
10.18 Show that
Eq. (10.11)
rests on good approximations.
10.19 Why is pipe length
L
not one of the governing parameters in pipe flow,
Section 10.2.1
?
10.20
Dis
cuss the differences between the buoyant production terms for
qw
and
θw
and how the differences might impact their budgets.
10.21 Why does
Eq. (10.38)
not use
θ(r)
?
of a stationary function of time
˜
References
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et al
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,
559
, 117-149.
Banta, R., 1985: Late-morning jump in TKE in the mixed layer over a mountain basin.
J.
Atmos. Sci.
,
42
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Bradley, E. F., R. A. Antonia, and A. J. Chambers, 1981a: Turbulence Reynolds number
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Bound.-Layer Meteor.
,
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Bradley, E. F., R. A. Antonia, and A. J. Chambers, 1981b: Temperature structure in the
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Bound.-Layer Meteor.
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23
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,
30
, 241-258.
Bradshaw, P., 1994: Turbulence: the chief outstanding difficulty of our subject.
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