1. Background
Methodology
Weather Conditions on Ozone
High Ozone Events
Results & Discussion
Acknowledgements
Ground level Ozone is a secondary pollutant made from primary
pollutant NOx & VOCs under UV radiation through reaction
mechanisms shown in Figure 1.
Ozone (O3) is a main component of photochemical smog. High
amounts of ground level O3 are known to have harmful effects on
human health. Table 1 shows various O3 alert levels and the risks
correlated with increased O3 concentrations
This project was funded by the Chemistry Department at CSU Channel Islands. We would like to
give special thanks to Simone Aloisio for mentoring and topic guidance & Haley Neel and Kelsie
Boatwright for previous work on data collection.
Effects weather conditions have on ozone concentrations in
Camarillo, California
Evy M. Monge, Ryan R. Rush, Simone Aloisio CSU Channel Islands Camarillo, CA 93012
Figure 3. Schematic diagram of instrument Figure 4. Front face of instrument
Ozone measurements are taken daily through instrument based UV-
absorption at 260 nm. A 2B Technologies Model 205 Ozone Monitor
(Figures 3&4) is used to collect five minute averages of ozone
concentrations in ambient air. The data is consolidated into one hour
averages and recorded with the corresponding weather data. Both
weather and ozone data is collected on site at the campus.
Figure 2. Source: Intergovernmental Panel on Climate Change, Fifth Assessment Report
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10.00
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90.00
9-May
6:30
12:30
18:30
10-May
6:30
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11-May
6:30
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12-May
6:30
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13-May
6:30
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14-May
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15-May
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16-May
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17-May
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18-May
6:30
12:30
18:30
PeakOzone(ppb)
Days (hours)
High Ozone Event May 2014
Effects of climate change on Ozone
HIGH OZONE DAYS
Ozone Grade F
Weighted Average 12.3
Orange Ozone Days 37
Red Ozone Days 0
Purple Ozone Days 0
GROUPAT RISK
Pediatric Asthma 18,297
Adult Asthma 55,541
COPD 29,842
Cardiovascular Disease 43,232
Diabetes 63,400
TOTAL POPULATION 835,981
Figure 1. Tropospheric Ozone formation. Table 1. Source: EPAAir Quality Index and levels of health concerns.
Table 2. Source: State of the Air 2014 Ventura County
O3 concentrations have a strong positive correlation to increased
temperatures (Figure 6). With contemporary issues such as global
warming and the continuing threat of increased temperatures, regions
like Camarillo, with warm-summer mediterranean climate, can
expect to have increased O3 concentrations.
Projected temperature increases are shown in Figure 2 where RCP 2.6
is a low-emission mitigation scenario and RCP 8.5 is a high emission
scenario. To date global temperatures haves increase by 0.8 C.
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Ozone[ppb]
Time (hrs)
Diurnal Pattern of Ozone
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70.0
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Ozone(ppb)
High Temperature (C)
Peak Ozone vs. High Temperature of the day
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Ozone(ppb)
Absolute Humidity (g/m)
Peak Ozone vs Absolute Humidity
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Ozone(ppb)
High Wind Speed (mph)
Peak Ozone vs. High wind Speed of the day
Table 2 shows that at least 25 % of the population are at great health
risks on high O3 alert days.
Figure 13. Probability of ozone alert days of concentrations higher than 80 ppb as a
function of temperature in New England, Los Angeles and the Southeast.
Figure 5. Diurnal pattern of ozone concentrations during the time of day Figure 6. Relationship of ozone concentrations with temperature
Figure 7. Relationship of ozone concentrations with humidity Figure 8. Relationship of ozone concentrations with wind speeds
Weather Condition Unit [Ozone]  50 ppb
Temperature  30 C 54 % Probability
 30 C 13 % Probability
 25 C 19 % Probability
< 25 C 14 % Probability
Absolute Humidity  7
g
m3
20 % Probability
 7
g
m3
15 % Probability
 5
g
m3
60 % Probability
 5
g
m3
14 % Probability
Wind Speeds  35 MPH 15 % Probability
 35 MPH 15 % Probability
Ozone measurements were taken from October 2013 – October 2014. The Diurnal
pattern of ozone (Figure 5) shows the time O3 concentrations peak. To date O3
concentrations were found to average around 40 ppb.
We found a strong positive correlations of O3 concentrations to temperature (Figure 6)
and a weak negative correlation of O3 to humidity (Figure 7) which is expected from
previous studies of O3. However Correlations between O3 concentrations and wind
speeds (Figure 8) showed a weak positive correlation contrary to previous studies.
A spike in ozone is seen on two different occasions. The high ozone event from October
had temperatures that were average for the area with majority of the winds coming from
the Southwest. The high ozone event from May had days with higher than average heat
with winds coming from the Southwest and the Northeast. Santa Ana winds come from
an inland north-east direction and with that we get higher temperatures and pollutants.
We hypothesize the spike in ozone came with these winds. Further observation is
needed to help understand why the unexplained high ozone event in October occurred.
The weather conditions such as; temperature, humidity and wind speeds were focused
on for O3 concentrations which were greater than or equal to 50 ppb. Red markers on
the graphs depict those concentrations that are greater than or equal to 50 ppb and are
used in the data analysis of weather conditions on O3 discussed below.
Temperature analysis showed that if temperatures are greater than or equal to 30 C the
probability of having O3 concentrations being 50 ppb or higher is 54% this in
comparison to the probability if temperatures were below 30C (Table 3) shows that O3
concentrations over 50 ppb are four more times likely to occur with increased
temperatures. Figure 8 shows the exponential probability of O3 concentrations being
greater than 80 ppb over 8 hours from 1980-1998 in three different regions in the U.S.A
with increased temperatures.
Humidity Analysis shows that if water vapor concentrations are less than or equal to 5
(grams/m3) the O3 concentrations that are greater than or equal to 50 ppb have a
60 % probability of occurring. This is believed to occur due to the low concentrations of
OH radical which is known to destroy O3.
Wind speed analysis shows there is no significant relationship to O3 concentrations.
Table 3. Weather conditions and their relationship to ozone concentrations  50 ppb
0
10
20
30
40
50
60
70
22-Oct
3:30
6:30
9:30
12:30
15:30
18:30
21:30
23-Oct
3:30
6:30
9:30
12:30
15:30
18:30
21:30
24-Oct
3:30
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9:30
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15:30
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21:30
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3:30
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26-Oct
3:30
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21:30
27-Oct
3:30
6:30
9:30
12:30
15:30
18:30
21:30
PeakOzone(ppb)
Days (Hours)
High Ozone Event October 2014
0
90
180
270
360
12:00 AM 6:00 AM 12:00 PM 6:00 PM 12:00 AM
CompassCoordinate
Time (hours)
Wind Direction during May
East 90
South 180
West 270
North 360
0
90
180
270
360
12:00 AM 6:00 AM 12:00 PM 6:00 PM 12:00 AM
CompasCoordinates
Time (hours)
Wind Direction during October 2014
Figure 9. High ozone event during a heat wave in May 2014 Figure 10. Wind directions during the month of May 2014 in compass coordinates.
Figure 11. High ozone event during average temperatures in October 2014 Figure 12. Wind directions during the month of October 2014 in compass coordinates