Geology Reference
In-Depth Information
1
(a)
3
2
1
0
(b)
2
1
0
0.15
(c)
0.10
0.05
0.00
10
100
1000
NO
x
(pptv)
Figure 13 Observed ozone production rates (P(O
3
)) and concentrations of HO
2
and OH
during SONEX (8-12 km altitude, 40-601N latitude) plotted a function of the
NO
x
concentration (NO
x
¼
observed NO
þ
modelled NO
2
). The observed
rates and concentrations are averaged over 24 h, using diel factors obtained
from a locally constrained box model. The lines on the three panels correspond
to model-calculated values for median upper tropospheric conditions as en-
countered during SONEX
19
Case Study I - A practical example of the dependence of ozone
production on NO
x
- An example of the experimental determination
of these relationships is shown in Figure 13, a comparison of observed
ozone production rates (P(O
3
)) and concentrations of HO
2
and OH
from the NASA SONEX mission
19
plotted as a function of NO
x
. The
data were taken from a suite of aircraft measurements between 8 and
12 km altitude at latitudes between 40 and 601N. The model data
suggest that P(O
3
) becomes independent of NO
x
above 70 pptv and
the turn-over point into a NO
x
-saturated regime occurs at about 300
pptv. The bulk of the experimental observation below [NO
x
]
o
300
