Geology Reference
In-Depth Information
d
½
O
3
dt
¼
C
þ
E
v
ð½
O
3
ft
½
O
3
Þ
H
þ
v
d
½
O
3
H
C is a term representative of the photochemistry (production or
destruction), E
v
the entrainment velocity, [O
3
]
ft
the concentra-
tion of free tropospheric ozone, v
d
the dry deposition velocity
and H the height of the boundary layer. The ozone budget
shown in Table 8 has been calculated both in the summer and
winter using the ozone continuity equation for a site in the
marine boundary layer.
(i) Describe the chemistry involved in calculating the term C
in the ozone continuity equation.
(ii) Given the magnitude of the photochemical terms in Table 8,
comment on the amount of available NO
x
.
(iii) How does the ability to make or destroy ozone change with
season?
(iv) What factors affect the magnitude of a deposition velocity?
(v) What role does entrainment play in the boundary layer?
(vi) What are the weaknesses of using this approach for the
calculation of chemical budgets?
(vii) Predict the likely diurnal cycle of ozone and hydrogen
peroxide in the remote marine boundary layer.
(xvi) Nitric acid has many potential loss processes in the troposphere.
Given that the reaction
OH
þ
HNO
3
!
H
2
O
þ
NO
3
has a rate constant of 2.0
10
13
cm
3
molecule
1
s
1
and the
hydroxyl radical concentration is 4
10
6
molecule cm
3
.The
Table 8 Calculated average ozone removal and addition rates according to
pathway, ppbv day
1
(upper part) and fractional contributions to
overall production or destruction patyways (lower part)
O
3
removal
O
3
addition
Photochemistry
(%)
Deposition
(%)
Photochemistry
(%)
Entrainment
(%)
Pathway
Summer
1.19
0.18
0.56
2.1
Winter
0.61
0.35
0.29
0.1
Summer
87
13
21
79
Winter
64
36
74
26
