Houston High Ozone May 8, 2008
- Ozone Animation
- Plume Animation
- Satellite Animation
- Satellite Image True Color - Texas 1:220 pm CDT (from UW SSEC)
- Satellite Image True Color - Houston 1:22 pm CDT (from UW SSEC)
- Winds Aloft at La Porte Airport
- Winds Aloft at La Porte Airport Mid-Day
- Winds Aloft at UH La Marque
High ozone was measured on the east side of the Houston area on Thursday, May 8th. The highest measured eight-hour average was 86 parts per billion (ppb) at the Wallisville Road Continuous Ambient Monitoring Station (CAMS) 617 north of Baytown and rated as Level Orange, Unhealthy for Sensitive Groups, on the U.S. Environmental Protection Agency (EPA) Air Quality Index (AQI) scale. The highest measured one-hour average was 116 parts per billion (ppb) for the hour from 5:00 to 6:00 p.m. Central Daylight Time (CDT), also at Wallisville Road CAMS 617. Level Orange ozone was measured at two of the 41 sites reporting complete data for the day in the Houston metro area and "Moderate" or higher ozone was measured at 41 sites. This day was the 7th day this year with Level Orange ozone measurements somewhere in the Houston area.
Skies were partly cloudy in the early morning, mostly clear mid-day, and then scattered high cirrus clouds moved in from the west in the afternoon. Winds were very moderate from the west and west-northwest in the morning and decreased and turned more to the south in the afternoon. The high temperature was 89 degrees Fahrenheit (°F) at George Bush Houston Intercontinental Airport, 92° at Hobby Airport, and 83° at Galveston Airport.
Regional background levels of ozone, in the air coming into the Houston area, ranged from about 48 to 57 ppb as indicated by the peak eight-hour averages at Conroe CAMS 78, Northwest Harris County CAMS 26, and Katy Park CAMS 559. The difference of 29 to 38 ppb between the measured eight-hour area maximum of 86 ppb and the approximate regional background level was likely caused by local air pollution sources in the Houston area. The approximate local contribution was about 34 to 44 percent of the measured 86 ppb area eight-hour peak.
The Plume Animation shows the estimated plume tracks from large industrial sources of oxides of nitrogen (NOx) and volatile organic compounds (VOC), along with the plume tracks for the centers of the broad urban plumes coming from downtown Houston and other major urban centers. The plume animation suggests that urban and industrial emissions from the Houston Ship Channel area were in the vicinity of some of the highest ozone measurements.