December 7, 2006
Poor air quality in California, poor correlation to AOD
The onset of cold clean air is keeping air quality conditions pretty good in the eastern half of the U.S., but California, Oregon, and Washington all had elevated fine particle concentrations today. Conditions were the worst in California, reaching unhealthy levels in much of the central part of the state. Both Fresno and Visalia had 1 hour peaks over 90 ug/m3, according to the California Air Resources Board. The pollutants must be fairly localized or have a composition to cause low impact to optical depth, since they can only be faintly seen in the MODIS Aqua image (below right). Aerosol optical depths from MODIS and GOES are both very low. Today would be an ideal case study of the conditions when AOD is poorly correlated with ground-level fine particles in the western U.S.
 |  |