1

Whose Ozone is this? 

High Ozone Concentrations in the Owens Valley: April 2008 

Prepared by Toni Richards, Air Quality Specialist 

Environmental Management Office 

Bishop Paiute Tribe 

May 8, 2008 

April is typically a time of unsettled weather in the Owens Valley. The Bishop Tribe’s Air Program installed an ozone 

monitor in September 2007. Programming was completed and real time data were available in October 2007. 

Assessment of the instrument is still in progress and results are being closely studied. As the start of the ozone season 

approached, some unexpectedly high concentrations were observed. This report is a preliminary examination of the 

weather associated with these high concentration days. The goal of this exercise is to improve our understanding in this 

assessment phase of the ozone monitor. 

Technical assistance for this report was graciously provided by Duane Ono, Deputy Air Pollution Control Officer for 

Great Basin Unified Air Pollution Control District, and Bob Baxter and Don Lehrman, Certified Consulting 

Meteorologists with Technical and Business Systems. 

Figure 1 shows daily ozone concentrations as measured on the Bishop Paiute Reservation during the month of April 2008. 

Four days (April 15, 19, 20 and 30), exceeded the federal standard. In addition, one day (April 21) exceeded the Tribal 

and State of California standard. 

FIGURE 1 

Ozone

April 2008

0

10

20

30

40

50

60

70

80

90

1-Apr-082-Apr-083-Apr-084-Apr-085-Apr-086-Apr-087-Apr-088-Apr-089-Apr-08

10-Apr-0811-Apr-0812-Apr-0813-Apr-0814-Apr-0815-Apr-0816-Apr-0817-Apr-0818-Apr-0819-Apr-0820-Apr-0821-Apr-0822-Apr-0823-Apr-0824-Apr-0825-Apr-0826-Apr-0827-Apr-0828-Apr-0829-Apr-0830-Apr-08

Date

Parts per billion

Ozone 8hr max

Ozone 1hr max

Ozone

The Bishop Tribal 8-hour 

standard is 70 parts per 

billion, the same as the 

California standard.

The federal 24-hour 

standard is 75 parts per 

billion.

The Bishop Tribal 1-hour 

stancard is 90 parts per 

billion, the same as the 

California standard.

There is no federal 1-hour 

standard

For real time air quality 

information go to

www.bishoptribeemo.com

Exceeds the 

federal and the 

Tribal 8-hour 

standard

Exceeds the 

Tribal 8-hour 

standard

For comparison, Figure 2 shows particulate matter concentrations during the same month. Unfortunately both particulate 

monitors experienced separate but unrelated mechanical problems during the early part of the month, so the data are not 

complete. Nevertheless, corresponding relatively high PM-10 concentrations are observed on April 14, 19 and 29. As we 

shall see, all of these days are associated with relatively high winds and frontal passage. 

Because of the time of year and the weather conditions, we suspect that the high ozone could be caused by stratospheric 

ozone intrusion. The PM and ozone events may not be related, but it’s interesting that they both happened at about the 

same time. 
April Ozone

2

FIGURE 2 

Particulate Matter Less than 10 Microns and Particulate Matter Less than 2.5 Microns

April 2008

0

20

40

60

80

100

120

140

160

180

200

1-Apr-082-Apr-083-Apr-084-Apr-085-Apr-086-Apr-087-Apr-088-Apr-089-Apr-08

10-Apr-0811-Apr-0812-Apr-0813-Apr-0814-Apr-0815-Apr-0816-Apr-0817-Apr-0818-Apr-0819-Apr-0820-Apr-0821-Apr-0822-Apr-0823-Apr-0824-Apr-0825-Apr-0826-Apr-0827-Apr-0828-Apr-0829-Apr-0830-Apr-08

Date

PM in micrograms per cubic meter

PM10 24-Hr MC

PM2.5 24-Hr MC

PM10 Hourly Max

PM2.5 Hourly Max

PM-10

The Bishop Tribal 24 hour 

standard is 50 micrograms 

per cubic meter, the same 

as the California standard.

The federal 24-hour 

standard is 150 

micrograms per cubic 

meter.

PM-2.5

The Bishop Tribal 24-hour 

standard is 35 micrograms 

per cubic meter, the same 

as the federal and 

California standard.

For real time air quality 

information go to

www.bishoptribeemo.com

PM-10 shut down

due to A/C problems

PM-2.5 shut down

due to chiller problems

Dust

SW Winds to 

45mph

The discussion below reviews the results for each of the high ozone days separately, including information on wind speed, 

direction and barometric pressure as well as model results from Hysplit and visibility information. 

APRIL 15, 2008

Figure 4 shows the particulate matter and ozone concentrations for April 15. Interestingly, the ozone and PM-10 peaks 

are within one hour of each other, with peak ozone concentrations at 9:00AM and peak PM-10 concentrations at 

10:00AM. 

FIGURE 4 

April 15, 2008

Particulate Matter and Ozone Hourly Concentrations

70 69

66

64

66

70

73

77

80

76

74 73

75

73

71

69

67 67

65 64 65 66 65

63

0

10

20

30

40

50

60

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Date

PM in micrograms per cubic meter

30

40

50

60

70

80

90

Ozone in parts per billion

PM-10

PM-2.5

Ozone
April Ozone

3

Figure 5 shows wind speed, gust and direction. Winds were out of the North nearly the entire day with peak gusts over 30 

miles per hour. Wind speeds peak at nearly the same time as ozone and PM-10 concentrations, near 9:00 or 10:00 AM 

PST. However, even higher PM-10 concentrations were observed on the previous day at 6:00 PM PST. 

FIGURE 5 

April 15, 2008

Wind Speed, Gust and Direction

0

5

10

15

20

25

30

35

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Wind speed in miles per hour

0

45

90

135

180

225

270

315

360

Wind direction in degrees

Wind

Gust

Direction

Figure 6 shows barometric pressure. Looking at just the data for April 15, it appears to be a period of rising barometric 

pressure. 

FIGURE 6 

April 15, 2008

Barometric Pressure

860

862

864

866

868

870

872

874

876

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Barometric pressure in millibars

Baro
April Ozone

4

However, if we extend the time frame to include April 14, the frontal passage becomes more apparent as shown in Figure 

7. 

FIGURE 7 

April 14-15, 2008

Barometric Pressure

860

862

864

866

868

870

872

874

876

878

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:051:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

14-Apr 15-Apr

Date and Time

Barometric Pressure in millibars

Baro

Figure 8 shows the 8-hour Hysplit back trajectories, computed at 2-hour intervals for the 6-hour period starting at 7:00 

AM PST. All trajectories point westward, with a slight northward trend in the latest trajectory. 
April Ozone

5

FIGURE 8 

Hysplit Trajectories April 15, 7:00 – 13:00 PST 

Figure 10 shows the corresponding wind and pollution roses. The wind rose confirms the predominant local wind 

direction from the North. Interestingly, while the pollution rose shows the highest concentrations to be from the North, 

high concentrations are also observed from the West quadrant. 

FIGURE 10 

Wind Rose April 15 Pollution Rose April 15 
April Ozone

6

April 2008 was consistently hazy. Therefore visibility images are included for each high ozone day to see if they provides 

additional information. In response to our inquiry, Duane Ono from GBUAPCD consulted with California Air Resources 

Board who confirmed the impact of a plume of Chinese dust during the period, indicating that “TOMS Absorbing Aerosol 

data show large dust export from Asia from April 14 to about the May 4, with persistent North American impacts.” 

The camera is mounted on the roof of the Environmental Management Office and downloads a picture of Mt. Tom 

(approximately 13 miles to West) at the start of each hour. The images are archived. Figure 11 shows the images for 

April 15. Some evidence of the haze is evident in the later afternoon photographs. 
April Ozone

7

FIGURE 11 

April 15 hourly photos 8:00AM to 3:00PM 
April Ozone

8

April 19, 2008

Figure 12 shows the particulate matter and ozone concentrations for April 19. This information is part of a 2-day pattern 

that includes April 20 (discussed below). As on April 15, high PM-10 concentrations precede the high ozone 

concentrations with high PM-10 concentration occurring 4:00 PM PST, and ozone concentrations continuing to rise at 

midnight. 

FIGURE 12 

April 19, 2008

Particulate Matter and Ozone Concentrations

52

46

37

40

36 35

39

57

63 64 65

58

62

68

70 71 71 70 70

66

72 73

76

79

-10

10

30

50

70

90

110

130

150

170

190

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

PM in micrograms per cubic meter

30

40

50

60

70

80

90

Ozone in parts per billion

PM-10

PM-2.5

Ozone

Figure 13 shows wind speed, gust and direction. On the 19th, winds were predominantly from the West Northwest gusting 

over 40 miles per hour. 
April Ozone

9

FIGURE 13 

April 19, 2008

Wind Speed, Gust and Direction

0

5

10

15

20

25

30

35

40

45

50

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Wind speed in miles per hour

0

45

90

135

180

225

270

315

360

Wind direction in degrees

Wind

Gust

Direction

Figure 14 shows barometric pressure and frontal passage is clearly apparent. 

FIGURE 14 

April 19, 2008

Barometric Pressure

858

859

860

861

862

863

864

865

866

867

868

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Barometric pressure in millibars

Baro

Figure 15 shows the 8-hour Hysplit back trajectories, computed at 2-hour intervals for the 6-hour period starting at 8:00 

PM PST on April 19. All trajectories point directly westward. 
April Ozone

10

FIGURE 15 

Hysplit Trajectories April 19, 20:00 to April 20, 2:00 PST 

Figure 16 shows the wind and pollution roses for the 19th. The wind roses confirm predominant local winds from the 

West and Southwest. The pollution roses indicate ozone from a variety of directions, with West dominanting. 

FIGURE 16 

Wind Rose April 19 Pollution Rose April 19 

Figure 17 shows the visibility images for April 19. Again, the hazy conditions are more apparent in the later afternoon, 

and these images clearly show the low visibility that prevailed in April. 
April Ozone

11

FIGURE 17 

April 19 hourly photos 11:00AM to 6:00PM 
April Ozone

12

April 20, 2008

Figure 18 shows the particulate matter and ozone concentrations for April 20. The April 20th episode appears to be a 

continuation of the episode that started on the 19th, with peak ozone concentrations at 1:00 AM PST, more or less 

coinciding with peak PM-10 concentrations, although values remain high throughout the 24-hour period. However, once 

again, much higher PM-10 concentrations are observed on the previous day, April 19th. 

FIGURE 18 

April 20, 2008

Particulate Matter and Ozone Concentrations

81

77

71

74

70

68

74

76 77 78 77 77 77 77 77 76 75

73

71

69

72 71

65 66

0

10

20

30

40

50

60

70

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

PM in 

micrograms per cubic meter

30

40

50

60

70

80

90

Ozone in parts per billion

PM-10

PM-2.5

Ozone

Figure 19 shows wind speed, gust and direction. As on April 15th, winds are predominantly from the North, gusting to 35 

miles per hour. The wind speeds had dropped slightly from 19th

. 
April Ozone

13

FIGURE 19 

April 20, 2008

Wind Speed, Gust and Direction

0

5

10

15

20

25

30

35

40

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Wind Speed in miles per hour

0

45

90

135

180

225

270

315

360

Wind Direction in degrees

Wind

Gust

Direction

Figure 20 shows barometric pressure. The frontal passage initiated on the 19th is clearly apparent. 

FIGURE 20 

April 20, 2008

Barometric Pressure

862

864

866

868

870

872

874

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Barometric Pressure in millibars

Baro

Figure 21 shows the 8-hour Hysplit back trajectories, computed at 2-hour intervals for the 6-hour period starting at 7:00 

AM PST. All trajectories point directly westward, with a slight northward trend in the later ones. 
April Ozone

14

FIGURE 21 

Hysplit Trajectories April 20, 7:00 to 13:00 PST 

Figure 22 shows the wind and pollution roses. The wind rose shows predominant North and Northwest winds, but the 

pollution rose indicates high ozone concentrations coming from a multiplicity of directions. 

FIGURE 22 

Wind Rose April 20 Pollution Rose April 20 

Figure 23 shows the visibility images. 
April Ozone

15

FIGURE 23 

April 20 hourly photos 8:00AM to 3:00PM 
April Ozone

16

April 30, 2008

Figure 24 shows the particulate matter and ozone concentrations for April 30. These are the highest ozone concentrations 

observed in April. While the ozone concentrations peak prior to the PM-10 concentrations, much higher PM-10 

concentrations are observed on the 29th, a pattern similar to the other high ozone days examined. 

FIGURE 24 

April 30, 2008

Particulate Matter and Ozone Concentrations

67

72 71

58 59

64

80 80 80

83 83

85 84 84

78

75 74

69

63 63 63 62 61 60

-10

0

10

20

30

40

50

60

70

80

90

1:00:05

Time

PM in micrograms per cubic meter

30

40

50

60

70

80

90

Ozone in parts per billion

PM-10

PM-2.5

Ozone

Figure 25 shows the wind speed, gust and direction. Winds are consistently from the North, gusting over 35 miles per 

hour. 
April Ozone

17

FIGURE 25 

April 30, 2008

Wind Speed, Gust and Direction

0

5

10

15

20

25

30

35

40

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Wind speed in miles per hour

0

45

90

135

180

225

270

315

360

Wind direction in degrees

Wind

Gust

Direction

Figure 26 shows barometric pressure. Once again, frontal passage is apparent. 

FIGURE 26 

April 30, 2008

Barometric Pressure

858

860

862

864

866

868

870

872

874

876

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Barometric Pressure in 

millibars

Baro
April Ozone

18

Figure 27 shows the 8-hour Hysplit back trajectories, computed at 2-hour intervals for the 6-hour period starting at 6:00 

AM PST. All trajectories point northwestward, with a slight increase in the northward trend in the later ones. 

FIGURE 27 

Hysplit Trajectories April 30 6:00 to 12:00 PST 

Figure 29 shows the wind and pollution roses. The wind roses confirm local North winds. The pollution roses show a 

predominant northern direction for the ozone, but with considerable variation from Northwest to Northeast. 
April Ozone

19

FIGURE 28 

Wind Rose April 30 Pollution Rose April 30 

Figure 29 shows the visibility images. 
April Ozone

20

FIGURE 29 

April 30 hourly photos 6:00AM to 1:00PM 
HIGH OZONE EPISODES ON THE BISHOP PAIUTE RESERVATION 

JUNE AND JULY 2008 

WILDFIRE IMPACTS 

Prepared by Toni Richards, Air Quality Specialist 

Bishop Paiute Tribe 

Environmental Management Office 

February 24, 2009 

In June and July of 2008, ozone monitors registered high values on the Bishop Paiute Reservation, 

with values exceeding the Tribal standard on June 10 and July 11 (73ppb and 74ppb), exceeding both 

the Tribal and federal standard on June 25 and 26, and on July 12 (76, 79 and 76ppb, respectively). 

In 2008, both June and July were active wildfire periods. According to the CalFire website: “On June 

20, 2008, a severe thunderstorm system moved through northern and central California resulting in 

over 6,000 total lightning strikes in more than 26 counties. The overwhelming number of lightning 

strikes, along with record dry conditions sparked over two thousand lightning fires.” 

(http://www.fire.ca.gov/index_incidents_overview.php)

The map below shows the fires that were ignited following the June 20th incident, known as the 

“lightening siege,” and August 11, 2008. The Bishop area was impacted by fires in Mariposa County, 

including the North Mountain, Silver, Mariposa and Oliver fires, all started 6/21/2008. Many of these 

fires were still burning in early July. Additional impacts came from the Clover fire which started in 

May, 2008 but continued to burn for through the middle of July for resource management purposes, 

and from the Piute Fire started on June 28, 2008. 

This report focuses the days 3 days that exceeded the tribal and federal 8-hour standard to improve 

our understanding of these high ozone episodes. 

JUNE 2008 

Figure 1 below shows ozone concentrations for June, 2008. 

FIGURE 1 

Ozone

June 2008

79

76

73

0

10

20

30

40

50

60

70

80

90

100

1-Jun-082-Jun-083-Jun-084-Jun-085-Jun-086-Jun-087-Jun-088-Jun-089-Jun-08

10-Jun-0811-Jun-0812-Jun-0813-Jun-0814-Jun-0815-Jun-0816-Jun-0817-Jun-0818-Jun-0819-Jun-0820-Jun-0821-Jun-0822-Jun-0823-Jun-0824-Jun-0825-Jun-0826-Jun-0827-Jun-0828-Jun-0829-Jun-0830-Jun-08

Date

Parts per billion

Ozone 8hr max

Ozone 1hr max

Ozone

The Bishop Tribal 8-hour 

standard is 70 parts per 

billion, the same as the 

California standard.

The federal 24-hour 

standard is 75 parts per 

billion.

The Bishop Tribal 1-hour 

standard is 90 parts per 

billion, the same as the 

California standard.

There is no federal 1-

hour standard.

For real time air quality 

information go to

www.bishoptribeemo.co

m

Exceeds the 

federal and the 

Tribal 8-hour 

standard

Exceeds the 

Tribal 8-hour 

standard

Figure 2 shows the corresponding PM concentrations. The 24-hour PM-2.5 standards on both days 

exceeded the Tribal and federal standards with concentrations of 39.23 and 35.54 μg/m3, 

respectively. 

FIGURE 2 

Particulate Matter Less than 10 Microns and Particulate Matter Less than 2.5 Microns

June 2008

50.48

69.89 59.82

764.40

211.70

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

800.00

900.00

1-Jun-082-Jun-083-Jun-084-Jun-085-Jun-086-Jun-087-Jun-088-Jun-089-Jun-08

10-Jun-0811-Jun-0812-Jun-0813-Jun-0814-Jun-0815-Jun-0816-Jun-0817-Jun-0818-Jun-0819-Jun-0820-Jun-0821-Jun-0822-Jun-0823-Jun-0824-Jun-0825-Jun-0826-Jun-0827-Jun-0828-Jun-0829-Jun-0830-Jun-08

Date

PM in micrograms per cubic meter

PM10 24-Hr MC

PM2.5 24-Hr MC

PM10 Hourly Max

PM2.5 Hourly Max

PM-10

The Bishop Tribal 24 hour 

standard is 50 micrograms 

per cubic meter, the same 

as the California standard.

The federal 24-hour 

standard is 150 

micrograms per cubic 

meter.

PM-2.5

The Bishop Tribal 24-hour 

standard is 35 micrograms 

per cubic meter, the same 

as the federal and 

California standard.

For real time air quality 

information go to

www.bishoptribeemo.com

PM-10 

exceeds tribal 

standard

Dust

S Winds to 

48mph

PM-2.5 

exceeds tribal 

standard

Fires

June 25, 2008 

Figure 3 shows the hourly ozone and PM concentrations for June 25. On that day, PM-2.5 values 

were quite high in the early morning hours, and PM-10 shows a peak at 7:00 AM. The peak in PM-10 

and the rising ozone levels coincide with a change in wind direction from the North to the South, 
Southeast, and an increase in wind speeds, as shown in Figure 4. The barometer is fairly stable, as 

seen in Figure 5. 

FIGURE 3 

Particulate Matter and Ozone Hourly Concentrations

June 25, 2008

0

50

100

150

200

250

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

PM in micrograms per cubic meter

0

10

20

30

40

50

60

70

80

90

100

Ozone in parts per billion

PM-10

PM-2.5

Ozone

FIGURE 4 

Wind June 25, 2008

0

5

10

15

20

25

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Wind speed in mph

0

50

100

150

200

250

300

350

400

Wind direction in degrees

Wind

Gust

Direction
FIGURE 5 

Barometric Presure

865

866

867

868

869

870

871

872

873

874

875

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Millibars

Baro

The hourly photographs shown in Figure 6 reveal a substantial reduction in visibility associated with 

the wildfires. The camera focuses on Mt. Tom at 13,500ft and at a distance of about 13 miles to the 

West of the Reservation. Its silhouette which usually dominates the landscape is barely apparent. 

The last photograph is photograph from June 1, 2008 with clear weather and good air quality for 

comparison. 

FIGURE 6 

Clear air day June 1, 2008 

June 26, 2008 

Figure 7 shows the hourly PM and ozone concentrations for June 26. In this case, there is a pattern 

of rising PM-2.5 concentrations followed by a period of high ozone concentrations. As on the 25th, 

winds are moderate, increasing in the afternoon, and the barometer is fairly stable (Figures 8 and 9). 

Figure 10 shows the corresponding sequence of photographs for the 26th

. As on the previous day, 

Mt. Tom is nearly completely obscured. 
FIGURE 7 

Particulate Matter and Ozone Hourly Concentrations

June 26, 2008

0

10

20

30

40

50

60

70

80

90

100

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

PM in micrograms per cubic meter

0

10

20

30

40

50

60

70

80

90

Ozone in parts per billion

PM-10

PM-2.5

Ozone

FIGURE 8 

Wind June 26, 2008

0

5

10

15

20

25

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Wind speed in mph

0

50

100

150

200

250

300

350

Wind direction in degrees

Wind

Gust

Direction
FIGURE 9 

Barometric Presure

865

866

867

868

869

870

871

872

873

874

875

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Millibars

Baro

FIGURE 10 

JULY 2008 

Figure 11 below shows the ozone concentrations for July 2008, with an exceedance of the Tribal 8-

hour standard on July 11 (74ppb) and exceedances of both the Tribal and federal standard on July 12 

(76ppb). On July 10, the Tribal 24-hour PM-10 was exceeded, and the PM-2.5 standard was 

approached but not exceeded. The high ozone values follow on the two succeeding days. We focus 

on the 12th when the federal 8-hour ozone standard was exceeded. 
FIGURE 11 

Ozone

July 2008

76 74

0

10

20

30

40

50

60

70

80

90

100

1-Jul-082-Jul-083-Jul-084-Jul-085-Jul-086-Jul-087-Jul-088-Jul-089-Jul-08

10-Jul-0811-Jul-0812-Jul-0813-Jul-0814-Jul-0815-Jul-0816-Jul-0817-Jul-0818-Jul-0819-Jul-0820-Jul-0821-Jul-0822-Jul-0823-Jul-0824-Jul-0825-Jul-0826-Jul-0827-Jul-0828-Jul-0829-Jul-0830-Jul-0831-Jul-08

Date

Parts per billion

Ozone 8hr max

Ozone 1hr max

Ozone

The Bishop Tribal 8-hour 

standard is 70 parts per 

billion, the same as the 

California standard.

The federal 24-hour 

standard is 75 parts per 

billion.

The Bishop Tribal 1-hour 

standard is 90 parts per 

billion, the same as the 

California standard.

There is no federal 1-

hour standard.

For real time air quality 

information go to

www.bishoptribeemo.co

m

Exceeds the 

federal and the 

Tribal 8-hour 

standard

Exceeds the 

Tribal 8-hour 

standard

FIGURE 12 

Particulate Matter Less than 10 Microns and Particulate Matter Less than 2.5 Microns

July 2008

51.50

66.84

0.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00

160.00

180.00

1-Jul-082-Jul-083-Jul-084-Jul-085-Jul-086-Jul-087-Jul-088-Jul-089-Jul-08

10-Jul-0811-Jul-0812-Jul-0813-Jul-0814-Jul-0815-Jul-0816-Jul-0817-Jul-0818-Jul-0819-Jul-0820-Jul-0821-Jul-0822-Jul-0823-Jul-0824-Jul-0825-Jul-0826-Jul-0827-Jul-0828-Jul-0829-Jul-0830-Jul-0831-Jul-08

Date

PM in micrograms per cubic meter

PM10 24-Hr MC

PM2.5 24-Hr MC

PM10 Hourly Max

PM2.5 Hourly Max

PM-10

The Bishop Tribal 24 hour 

standard is 50 micrograms 

per cubic meter, the same 

as the California standard.

The federal 24-hour 

standard is 150 

micrograms per cubic 

meter.

PM-2.5

The Bishop Tribal 24-hour 

standard is 35 micrograms 

per cubic meter, the same 

as the federal and 

California standard.

For real time air quality 

information go to

www.bishoptribeemo.com

PM-10 

exceeds tribal 

standard

July 12, 2008 

Figure 13 shows the hourly particulate matter and ozone concentrations. While the PM-2.5 

concentrations are moderately high, they had been even higher in the 2 days prior. Figure 14 shows 

wind speed and direction revealing light to moderate winds increasing in the afternoon. Figure 15 

shows barometric pressure. Figure 16 shows the corresponding visibility information, revealing 

substantially reduced visibility throughout the day. 
FIGURE 13 

Particulate Matter and Ozone Hourly Concentrations

July 12, 2008

0

20

40

60

80

100

120

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

PM in micrograms per cubic meter

0

10

20

30

40

50

60

70

80

90

Ozone in parts per billion

PM-10

PM-2.5

Ozone

FIGURE 14 

Wind July 12, 2008

0

5

10

15

20

25

30

35

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Wind speed in mph

0

50

100

150

200

250

300

350

Wind direction in degrees

Wind

Gust

Direction
FIGURE 15 

Barometric Pressure July 12, 2008

870

871

872

873

874

875

876

877

878

879

880

1:00:052:00:053:00:054:00:055:00:056:00:057:00:058:00:059:00:05

10:00:0511:00:0512:00:0513:00:0514:00:0515:00:0516:00:0517:00:0518:00:0519:00:0520:00:0521:00:0522:00:0523:00:05

0:00:05

Time

Millibars

Baro

FIGURE 16