April 15, 2009
Mostly Good Air Quality; Beginning of Ozone Season in Texas?
Several Texas cities including Austin and Dallas reached code yellow (moderate) levels of ozone for several hours this afternoon. Widespread moderate ozone levels are forecast for tomorrow across many parts of Texas, including Houston and El Paso. With temperatures in the 70s, abundant sunshine is likely a factor in the elevated ozone levels. See the animated image of ozone levels today from AIRNow, below right. Also note that PM2.5 values as reported by AIRNow (below left) were primarily in the code green (good) range today.
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Terra MODIS true color image shows cloud cover in the northeast and much of the west. The corresponding Terra MODIS AOD shows mostly clean air (low levels of particles), with a blip of high AOD likely related to fires (see NOAA HMS) in Oklahoma, and also in Canada. However, NOAA HMS is not showing visible smoke plumes in the Gulf of Mexico from fires in Central America as in previous days. Note that in the MODIS true color image, below left, one could mistake the sunglint over the Gulf of Mexico (off the Texas coast) for smoke, but closer examination reveals that this is indeed not smoke. The sunglint has a vertical pattern parallel to and in the middle of the satellite swath.
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