Aug 07 2012
A Lot of Dust in the Air
There is a lot of dust in the air. From whence does it come? NASA and university scientists have made the first measurement-based estimate of the amount and composition of tiny airborne particles that arrive in the air over North America each year. With a 3-D view of the atmosphere now possible from satellites, the scientists calculated that dust, not pollution, is the main ingredient of these imports. According to a new analysis of NASA satellite data, 64 million tons of dust, pollution and other particles that have potential climate and human health effects survive a trans-ocean journey to arrive over North America each year. This is nearly as much as the estimated 69 million tons of aerosols produced domestically from natural processes, transportation and industrial sources. The results were published Aug. 2 in the journal Science.