July 5, 2009
Smoke over California, Fireworks and PM2.5
The lightning sparked fires, discussed in yesterday’s post by Nikisa, in Trinity and Toulumne Counties in California have not been fully contained their smoke is visible on the MODIS AQUA True Color Image (top left, source: UW MODIS Direct). PM2.5 concentrations in California varied from Good to Moderate due the smoke of these fires. The early morning Moderate PM2.5 AQI Levels (top right, source: EPA Airnow) might be due to fireworks displays that can temporarily increase the levels of local air pollution. Pollution increases after sunset when fireworks displays are held, and can continue into the next day if a stagnant air mass enables the particles to remain to be trapped in a location for an extended period of time. PM2.5 concentrations peaked in the Baltimore-Washington area between 8:00-10:00 pm LT due to firework displays on the National Mall and Baltimore’s InnerHarbor (bottom left) Ozone concentrations (bottom right, source EPA Airnow) were good throughout most of the states with California, Idaho and Utah experiencing Moderate AQI levels as the day progressed.
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