Weekend/Weekday Ozone Observations in the South Coast Air Basin

Table 4.5-1
Ambient NOx (ppb) Associated with CO and Black Carbon at On-Road and Regional Locations in the SoCAB 1
4-32
Sampling Mon, 10/2/00 Wed, 10/4/00 Sat, 10/7/00 Sun, 10/8/00
ID Location Period Obs. NOx [CO] NOx [BC] Obs. NOx [CO] NOx [BC] Obs. NOx [CO] NOx [BC] Obs. NOx [CO] NOx [BC]
Concentration (ppb) ± standard deviation
IH1 Industry Hills 0200-0245 36 ± 4 29 ± 1 22 ± 3 12 ± 1 47 ± 2 24 ± 1 54 ± 8 26 ± 5
CV1 Covina Loop 0300-0345 70 ± 19 68 ± 29 37 ± 16 52 ± 35 64 ± 8 45 ± 12 73 ± 29 30 ± 4
DS1 Dodger Stadium 0415-0500 26 ± 1 22 ± 6 25 ± 4 20 ± 4 21 ± 2 14 ± 14 73 ± 8 28 ± 3
CO1 Compton Loop 0515-0600 122 ± 49 82 ± 48 100 ± 52 81 ± 24 60 ± 24 36 ± 22 111 ± 26 45 ± 11
HF1 Pasadena Fwy 0630-0715 93 ± 41 37 ± 5 58 ± 13 24 ± 7 72 ± 17 23 ± 8 102 ± 11 41 ± 3
DS2 Dodger Stadium 0730-0815 102 ± 64 51 ± 9 56 ± 14 46 ± 10 46 ± 9 15 ± 2 79 ± 15 33 ± 8
CO2 Compton Loop 0830-0915 149 ± 64 191 ± 105 106 ± 42 225 ± 183 102 ± 35 157 ± 88 117 ± 25 71 ± 32
CV2 Covina Loop 0930-1015 98 ± 20 203 ± 96 105 ± 64 160 ± 79 106 ± 27 75 ± 25 120 ± 46 55 ± 21
IH2 Industry Hills 1030-1115 37 ± 1 47 ± 6 28 ± 1 30 ± 3 29 ± 1 18 ± 1 31 ± 7 12 ± 3
PO1 Pomona Loop 1130-1215 104 ± 19 168 ± 86 78 ± 32 201 ± 82 90 ± 27 71 ± 36 98 ± 36 68 ± 34
Percent of sum of NOx[CO] + NOx[BC] ± standard error
IH1 Industry Hills 0200-0245 9 55 ± 0.9 45 ± 0.9 9 65 ± 0.7 35 ± 0.7 9 66 ± 0.3 34 ± 0.3 9 67 ± 0.8 33 ± 0.8
CV1 Covina Loop 0300-0345 6 52 ± 4.2 48 ± 4.2 6 43 ± 7.6 57 ± 7.6 4 59 ± 3.4 41 ± 3.4 4 70 ± 3.8 30 ± 3.8
DS1 Dodger Stadium 0415-0500 6 54 ± 2.4 46 ± 2.4 10 56 ± 1.6 44 ± 1.6 7 66 ± 5.9 34 ± 5.9 9 72 ± 1.0 28 ± 1.0
CO1 Compton Loop 0515-0600 7 60 ± 5.5 40 ± 5.5 5 52 ± 6.2 48 ± 6.2 8 64 ± 5.6 36 ± 5.6 7 71 ± 2.6 29 ± 2.6
HF1 Pasadena Fwy 0630-0715 10 69 ± 2.2 31 ± 2.2 9 70 ± 2.1 30 ± 2.1 7 76 ± 3.1 24 ± 3.1 4 71 ± 0.6 29 ± 0.6
DS2 Dodger Stadium 0730-0815 6 63 ± 5.3 37 ± 5.3 6 55 ± 4.3 45 ± 4.3 7 74 ± 1.6 26 ± 1.6 9 71 ± 1.6 29 ± 1.6
CO2 Compton Loop 0830-0915 6 47 ± 5.9 53 ± 5.9 5 38 ± 6.3 62 ± 6.3 4 43 ± 10.6 57 ± 10.6 7 63 ± 5.5 37 ± 5.5
CV2 Covina Loop 0930-1015 6 35 ± 3.3 65 ± 3.3 5 40 ± 10.4 60 ± 10.4 8 59 ± 3.9 41 ± 3.9 7 68 ± 4.7 32 ± 4.7
IH2 Industry Hills 1030-1115 7 44 ± 1.2 56 ± 1.2 5 48 ± 1.2 52 ± 1.2 5 62 ± 1.0 38 ± 1.0 7 72 ± 1.1 28 ± 1.1
PO1 Pomona Loop 1130-1215 4 41 ± 7.2 59 ± 7.2 5 30 ± 5.8 70 ± 5.8 7 57 ± 3.4 43 ± 3.4 8 59 ± 2.6 41 ± 2.6
1 Appportionment derived from the following multiple linear regression equation: [NOx, ppb] = -1.34 + 39.42 * [CO, ppm] + 14.84 * [BC, µg/m 3 ].