Weekend/Weekday Ozone Observations in the South Coast Air Basin

Table 3.3-1b
Day-of-the-Week Differences in Diurnal Variations of Photochemical Reactivity of
Volatile Organic Compounds at Pico Rivera, Summer 1999-2000
Hour (PDT) Sunday Monday Tuesday Wednesday Thursday Friday Saturday
xylenes/benzene 0 2.85 3.15 3.24 3.34 3.26 2.97 2.83
3 2.81 2.60 2.94 3.14 3.52 3.02 2.95
6 2.66 2.76 2.99 2.84 3.02 3.06 3.05
9 2.02 2.70 3.26 3.00 2.93 2.83 2.52
12 1.44 2.74 2.83 2.99 2.74 2.60 1.89
15 1.77 2.82 3.00 3.30 3.24 2.87 2.25
18 2.47 3.04 3.11 3.53 3.22 3.07 2.81
21 2.76 2.71 3.01 3.12 3.31 3.08 2.96
formaldehyde (ppb) 0 4.9 5.9 6.4 4.5 4.1 4.3 4.6
3 4.5 4.4 5.8 5.7 5.1 4.5 4.1
6 5.7 5.8 7.8 6.2 4.8 5.9 5.3
9 6.8 9.4 10.6 10.1 7.1 8.3 7.6
12 10.5 8.0 10.3 10.0 9.3 9.1 9.3
15 8.7 7.5 8.3 6.3 6.4 7.4 7.6
18 6.3 5.6 7.4 5.8 5.3 5.8 5.6
21 5.5 5.2 6.3 5.6 4.1 5.1 5.0
formaldehyde/pams 0 3% 3% 3% 3% 4% 4% 3%
3 3% 2% 3% 3% 4% 4% 4%
6 4% 2% 3% 2% 3% 4% 4%
9 7% 5% 5% 6% 5% 7% 7%
12 11% 7% 8% 8% 6% 8% 10%
15 12% 7% 8% 7% 6% 8% 10%
18 8% 5% 6% 5% 5% 6% 7%
21 5% 4% 5% 4% 3% 5% 4%
MIR sum of PAMS 0 3.2 3.2 3.3 3.3 3.3 3.3 3.3
3 3.1 2.8 3.0 3.0 3.2 3.1 3.0
6 3.0 3.1 3.1 2.9 3.1 3.3 3.0
9 2.9 3.0 3.0 3.1 3.1 3.2 3.0
12 2.7 3.0 2.9 3.1 2.8 3.0 2.8
15 3.0 3.2 3.2 3.4 3.1 3.3 3.1
18 3.4 3.5 3.4 3.5 3.3 3.4 3.5
21 3.4 3.4 3.3 3.3 3.2 3.1 3.3
MIR sum of PAMS + 0 3.4 3.4 3.5 3.4 3.4 3.6 3.6
carbonyl compounds 3 3.3 3.0 3.2 3.1 3.3 3.3 3.3
6 3.3 3.2 3.2 2.9 3.2 3.4 3.2
9 3.4 3.3 3.3 3.3 3.3 3.5 3.4
12 3.5 3.3 3.4 3.4 3.1 3.5 3.4
15 3.7 3.6 3.6 3.6 3.4 3.6 3.7
18 3.9 3.7 3.7 3.7 3.5 3.8 3.9
21 3.7 3.6 3.6 3.5 3.3 3.4 3.5
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