August 15, 2012

Dense Smoke over the Western Half of the United States; Cloud Capped Boundary Layer and Smoke Over Baltimore

Fires across California and Nevada, Oregon, Idaho, Wyoming and Montana are producing a large amount of smoke (leading to high AOD) across much of the western half of the United States, as shown in today's MODIS Terra "true color" and AOD images (top left and right images). The National Weather Service issued an Excessive Heat Warning for Washington and Oregon as a high pressure over the region will lead to very hot temperatures across the region until Saturday. Temperatures are forecasted over the region to be very hot temperatures across the region from Wednesday through Saturday. The hottest days are forecast to be Thursday and Friday when inland valley temps should reach 100 degrees. NRL NAAPS Friday's forecast product shows the presence of this smoke across the entirety of the United States.

Regarding the United States air quality we had Moderate ozone concentrations along the Ohio River Valley, the Rocky Mountain States and California. PM2.5 reached code Purple and Red AQI levels in locations near the California wildfires. The locations with smoke recorded Code Yellow concentrations.

Lidar observations at UMBC show a cloud capped boundary layer, with clouds advecting during our operation. The boundary layer extended up to 1 km with particle pollution also present up to 4 km. This particle pollution is most likely smoke from the Pacific Northwest as indicated from HYSPLIT backtrajectories (not shown here).

Posted by Ruben Delgado at August 15, 2012 10:37 PM

I just want to say thanks for maintaining this excellent and useful site. Too many people have no idea how poor our air quality is - they assume just because they can't see ozone it poses no threat when in fact it is even more toxic to trees than it is to people. A free book about that here:

and a blog here:

Thanks again,

Posted by: Gail at August 16, 2012 12:26 PM
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