Moderate PM2.5 were registered in pretty much the half eastern part of the US (top left). In the west, unhealthy levels were reached in California and Idaho. Fires continue taking place in several regions (top right). According to MODIS web, the majority of the wildfires burn in the forests of Idaho, while large fires in northwestern Wyoming are producing heavy smoke plumes which are driven strongly eastward by heavy winds. Smoke in southern Oregon blows more southerly, while the northern California fires spread smoke locally. The clouds likely were carrying rains, which help dampen fires, but thunderstorms are a mixed blessing - they also bring strong winds, which encourage fire spread, and the accompanying lightning may ignite new blaze. By August 29, the National Interagency Fire Center reported that 28 large fires remained active, with 15,800 personnel working to suppress those fires. The number of acres burned was reported as 696,366. The number of large fires by state was: 8 in California, 5 in Idaho, 6 in Montana, 5 in Oregon, 2 in Washington, 1 in Utah and 1 in Wyoming. The number of large fires contained this year was 293. A "large" fire is defined as a wildfire of 100 acres or more occurring in timber or a wildfire of 300 acres or more occurring in grass/sage. MODIS images detect large fires, but also can detect fires much smaller than this designation (bottom).
SPECIAL FEATURE: Tracking Dust Across the Atlantic
Hundreds of millions of tons of dust are picked up from the deserts of Africa and blown across the Atlantic Ocean each year. That dust helps build beaches in the Caribbean and fertilizes soils in the Amazon. It affects air quality in North and South America. And some say dust storms might play a role in the suppression of hurricanes and the decline of coral reefs.
The natural-color images (top), were captured by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite on July 31 and August 1-2, 2013. The dust also was detected by the Ozone Mapping Profiling Suite (OMPS) on Suomi NPP. The maps below show the relative concentrations of aerosol particles on the same dates.